One Health surveillance of colistin-resistant Enterobacterales in Belgium and the Netherlands between 2017 and 2019

BACKGROUND

Colistin serves as the last line of defense against multidrug resistant Gram-negative bacterial infections in both human and veterinary medicine. This study aimed to investigate the occurrence and spread of colistin-resistant Enterobacterales (ColR-E) using a One Health approach in Belgium and in the Netherlands.

METHODS

In a transnational research project, a total of 998 hospitalized patients, 1430 long-term care facility (LTCF) residents, 947 children attending day care centres, 1597 pigs and 1691 broilers were sampled for the presence of ColR-E in 2017 and 2018, followed by a second round twelve months later for hospitalized patients and animals. Colistin treatment incidence in livestock farms was used to determine the association between colistin use and resistance. Selective cultures and colistin minimum inhibitory concentrations (MIC) were employed to identify ColR-E. A combination of short-read and long-read sequencing was utilized to investigate the molecular characteristics of 562 colistin-resistant isolates. Core genome multi-locus sequence typing (cgMLST) was applied to examine potential transmission events.

RESULTS

The presence of ColR-E was observed in all One Health sectors. In Dutch hospitalized patients, ColR-E proportions (11.3 and 11.8% in both measurements) were higher than in Belgian patients (4.4 and 7.9% in both measurements), while the occurrence of ColR-E in Belgian LTCF residents (10.2%) and children in day care centres (17.6%) was higher than in their Dutch counterparts (5.6% and 12.8%, respectively). Colistin use in pig farms was associated with the occurrence of colistin resistance. The percentage of pigs carrying ColR-E was 21.8 and 23.3% in Belgium and 14.6% and 8.9% in the Netherlands during both measurements. The proportion of broilers carrying ColR-E in the Netherlands (5.3 and 1.5%) was higher compared to Belgium (1.5 and 0.7%) in both measurements. mcr-harboring E. coli were detected in 17.4% (31/178) of the screened pigs from 7 Belgian pig farms. Concurrently, four human-related Enterobacter spp. isolates harbored mcr-9.1 and mcr-10 genes. The majority of colistin-resistant isolates (419/473, 88.6% E. coli; 126/166, 75.9% Klebsiella spp.; 50/75, 66.7% Enterobacter spp.) were susceptible to the critically important antibiotics (extended-spectrum cephalosporins, fluoroquinolones, carbapenems and aminoglycosides). Chromosomal colistin resistance mutations have been identified in globally prevalent high-risk clonal lineages, including E. coli ST131 (n = 17) and ST1193 (n = 4). Clonally related isolates were detected in different patients, healthy individuals and livestock animals of the same site suggesting local transmission. Clonal clustering of E. coli ST10 and K. pneumoniae ST45 was identified in different sites from both countries suggesting that these clones have the potential to spread colistin resistance through the human population or were acquired by exposure to a common (food) source. In pig farms, the continuous circulation of related isolates was observed over time. Inter-host transmission between humans and livestock animals was not detected.

CONCLUSIONS

The findings of this study contribute to a broader understanding of ColR-E prevalence and the possible pathways of transmission, offering insights valuable to both academic research and public health policy development.

Safety and Immunogenicity of a Revaccination With a Respiratory Syncytial Virus Prefusion F Vaccine in Older Adults: A Phase 2b Study

BACKGROUND

In the previous (parent) study, 2 doses of different formulations of an investigational vaccine against respiratory syncytial virus (RSVPreF3 OA) were well tolerated and immunogenic in older adults. This multicenter phase 2b extension study assessed safety and immunogenicity of a revaccination (third) dose of the 120 μg RSVPreF3-AS01E formulation.

METHODS

In total, 122 older adults (60-80 years), previously vaccinated with 2 doses of RSVPreF3-AS01E formulations (containing 30, 60, or 120 μg RSVPreF3 antigen), received an additional 120 μg RSVPreF3-AS01E dose 18 months after dose 2. Vaccine safety was evaluated in all participants up to 6 months and immunogenicity in participants who received 120 μg RSVPreF3-AS01E doses until 1 month after dose 3.

RESULTS

Similar to the parent study, mostly mild-to-moderate solicited adverse events and no vaccine-related serious adverse events or potential immune-mediated disorders were reported. Neutralizing titers and cell-mediated immune responses persisted for 18 months after 2-dose vaccination. Dose 3 increased RSV-specific neutralizing titers against RSV-A and RSV-B and median CD4+ T-cell frequencies. After dose 3, RSV-specific neutralizing titers but not CD4+ T-cell frequencies were below levels detected 1 month after dose 1.

CONCLUSIONS

Revaccination with 120 μg RSVPreF3-AS01E 18 months after dose 2 is well tolerated and immunogenic in older adults.

CLINICAL TRIALS REGISTRATION

NCT04657198; EudraCT, 2020-000692-21.

Efficacy and safety of respiratory syncytial virus prefusion F protein vaccine (RSVPreF3 OA) in older adults over 2 RSV seasons

BACKGROUND

The adjuvanted RSV prefusion F protein-based vaccine (RSVPreF3 OA) was efficacious against RSV-related lower respiratory tract disease (RSV-LRTD) in ≥60-year-olds over 1 RSV season. We evaluated efficacy and safety of 1 RSVPreF3 OA dose and of 2 RSVPreF3 OA doses given 1 year apart against RSV-LRTD over 2 RSV seasons post-dose 1.

METHODS

In this phase 3, blinded trial, ≥60-year-olds were randomized (1:1) to receive RSVPreF3 OA or placebo pre-season 1. RSVPreF3 OA recipients were re-randomized (1:1) to receive a second RSVPreF3 OA dose (RSV_revaccination group) or placebo (RSV_1dose group) pre-season 2; participants who received placebo pre-season 1 received placebo pre-season 2 (placebo group). Efficacy of both vaccine regimens against RSV-LRTD was evaluated over 2 seasons combined (confirmatory secondary objective, success criterion: lower limits of 2-sided confidence intervals [CIs] around efficacy estimates >20%).

RESULTS

The efficacy analysis comprised 24,967 participants (RSV_1dose: 6227, RSV_revaccination: 6242, placebo: 12,498). Median efficacy follow-up was 17.8 months. Efficacy over 2 seasons of 1 RSVPreF3 OA dose was 67.2% (97.5% CI: 48.2-80.0) against RSV-LRTD and 78.8% (95% CI: 52.6-92.0) against severe RSV-LRTD. Efficacy over 2 seasons of a first dose followed by revaccination was 67.1% (97.5% CI: 48.1-80.0) against RSV-LRTD and 78.8% (95% CI: 52.5-92.0) against severe RSV-LRTD. Reactogenicity/safety of the revaccination dose were similar to dose 1.

CONCLUSION

One RSVPreF3 OA dose was efficacious against RSV-LRTD over 2 RSV seasons in ≥60-year-olds. Revaccination 1 year post-dose 1 was well tolerated but did not seem to provide additional efficacy benefit in the overall study population. ClinicalTrials.gov registration: NCT04886596.

Epidemiology and molecular typing of multidrug-resistant bacteria in tertiary hospitals and nursing homes in Flanders, Belgium

This study aimed to map MDRO carriage and potential transmission within and between three Flemish tertiary care hospitals and their neighbouring nursing homes. A cross-sectional MDRO prevalence survey was organized between October 2017 and February 2019. Perianal swabs were cultured for detection of MDRO. Determination of clonal relatedness based on wgMLST allelic profiles was performed. The prevalence of MDRO in Belgian hospitals and NHs is on the rise, compared to previous studies, and transmission in and between institutions is observed. These results re-emphasize the need for a healthcare network-wide infection prevention strategy in which WGS of MDRO strains can be supportive.

Safety and Immunogenicity of Respiratory Syncytial Virus Pre-fusion Maternal Vaccine Co-administered with Diphtheria-Tetanus-Pertussis Vaccine: A Phase 2 Study

BACKGROUND

Respiratory syncytial virus (RSV) fusion protein stabilized in the prefusion conformation (RSVPreF3) was under investigation as a maternal vaccine.

METHODS

This phase 2, randomized, placebo-controlled, single-dose, multicenter study enrolled healthy, non-pregnant women, randomized 1:1:1:1:1 to five parallel groups studying RSVPreF3 (60 or 120 µg) co-administered with diphtheria, tetanus, and acellular pertussis vaccine (dTpa) or placebo, and dTpa co-administered with placebo. Safety and humoral immune responses were assessed. An extension phase also assessed a RSVPreF3 120 μg vaccination 12-18 months post-first vaccination.

RESULTS

The safety profile of RSVPreF3 was unaffected by dose or dTpa co-administration. Solicited and unsolicited adverse events (AEs) were evenly distributed across study groups. Injection-site pain was higher following the second vaccination vs the first vaccination. Medically attended AEs were rare (<5% overall). Both RSVPreF3 dose levels (alone and with dTpa) were immunogenic, increasing levels of RSV-A neutralizing antibody ≥8 fold and anti-RSVPreF3 IgG antibody ≥11 fold at 1 month post-vaccination, which persisted at 12-18 months post-vaccination; modest 2-fold increases were observed with a second RSVPreF3 vaccination.

CONCLUSIONS

This study indicates RSVPreF3 co-administration with dTpa induces robust immune responses and is well tolerated, regardless of the RSVPreF3 dose level used.

CLINICAL TRIALS REGISTRATION

NCT04138056.

Immunogenicity, safety, and preliminary efficacy evaluation of OVX836, a nucleoprotein-based universal influenza A vaccine candidate: a randomised, double-blind, placebo-controlled, phase 2a trial

BACKGROUND

OVX836, a recombinant vaccine containing the nucleoprotein of the influenza A virus A/WSN/1933 (H1N1) and the oligomerisation domain OVX313, has displayed a good safety profile and elicited dose-dependent humoral and cellular immune responses at 90 μg or 180 μg (intramuscularly) in previous clinical trials. The aim of this study was to explore higher doses, since no maximum tolerated dose had been reached.

METHODS

In this phase 2a, randomised, double-blind, placebo-controlled study, we recruited 137 healthy adults aged 18-55 years in a single centre in Belgium. Participants were randomly assigned (interactive web response system; block size=4) using SAS (version 9.4) to receive one single intramuscular administration of OVX836 influenza vaccine at three doses (180 μg [n=33], 300 μg [n=35], and 480 μg [n=36]) or placebo (n=33). The two primary endpoints were the safety and the cell-mediated immune response to OVX836 at the three doses in terms of change of nucleoprotein-specific IFNγ spot forming cell (SFC) frequencies in the peripheral blood mononuclear cell (PBMC) population, measured by IFNγ ELISpot, at day 8 versus pre-injection baseline (day 1). The population used for the safety analysis is the modified intention-to-treat cohort. The population used for the immunogenicity analysis is the per-protocol cohort. This trial is registered with ClinicalTrials.gov, NCT05060887, and EudraCT, 2021-002535-39.

FINDINGS

Participants were recruited between Nov 15, 2021, and Feb 1, 2022. OVX836 had a favourable safety profile up to 480 μg without reaching the maximum tolerated dose, and showed a good safety profile at all doses with mild local and systemic reactogenicity. 7 days after vaccination, although no significant differences were observed between the doses, OVX836 increased the frequency of nucleoprotein-specific IFNγ SFCs per million PBMCs from days 1 to 8 (primary endpoint): by 124 SFCs per 106 PMBCs (95% CI 67 to 180; p=0·002) at 180 μg; by 202 SFCs per 106 PMBCs (95% CI 138 to 267; p<0·0001) at 300 μg; by 223 SFCs per 106 PMBCs (95% CI 147 to 299; p<0·0001) at 480 μg; and decreased by 1 SFCs per 106 PMBCs (95% CI -24 to 22] in the placebo group (Kruskal-Wallis test p<0·0001 followed by Mann-Whitney's tests; per-protocol cohort). Dose-dependent and polyfunctional nucleoprotein-specific CD4 T-cell responses were observed, and CD8 T-cell responses were elicited at 300 μg and 480 μg (secondary endpoints).

INTERPRETATION

OVX836 appears to be a safe and well tolerated candidate vaccine that elicits humoral and cellular nucleoprotein-specific immune responses (including CD8 T cells at the highest dose levels) and showed a preliminary signal of protection against influenza. Therefore, OVX836 is a promising vaccine candidate for universal influenza A prevention, that warrants further trials.

FUNDING

OSIVAX, Bpifrance, Wallonia Region, and the EUs Horizon 2020 Research and Innovation Program.

Safety and immunogenicity of a novel multivalent OspA-based vaccine candidate against Lyme borreliosis: a randomised, phase 1 study in healthy adults

BACKGROUND

Lyme borreliosis, potentially associated with serious long-term complications, is caused by the species complex Borrelia burgdorferi sensu lato. We investigated a novel Lyme borreliosis vaccine candidate (VLA15) targeting the six most common outer surface protein A (OspA) serotypes 1-6 to prevent infection with pathogenic Borrelia spp prevalent in Europe and North America.

METHODS

This was a partially randomised, observer-masked, phase 1 study in healthy adults older than 18 years to younger than 40 years (n=179) done in trial sites in Belgium and the USA. Following a non-randomised run-in phase, a sealed envelope randomisation method was applied with a 1:1:1:1:1:1 ratio; three dose concentrations of VLA15 (12 μg, 48 μg, and 90 μg) were administered by intramuscular injection on days 1, 29, and 57. The primary outcome was safety (frequency of adverse events up to day 85) assessed in participants who received at least one vaccination. Immunogenicity was a secondary outcome. The trial is registered with ClinicalTrials.gov, NCT03010228, and is complete.

FINDINGS

Between Jan 23, 2017 and Jan 16, 2019, of 254 participants screened for eligibility, 179 were randomly assigned into six groups: alum-adjuvanted 12 μg (n=29), 48 μg (n=31), or 90 μg (n=31) and non-adjuvanted 12 μg (n=29 participants), 48 μg (n=29), or 90 μg (n=30). VLA15 was safe and well tolerated and the majority of adverse events were mild or moderate. Overall, adverse events were more frequent in the 48 μg and 90 μg groups (range 28-30 participants [94-97%]) when compared with the 12 μg group (25 [86%] participants, 95% CI 69·4-94·5) for adjuvanted and non-adjuvanted groups. Common local reactions were tenderness (151 [84%] participants; 356 events, 95% CI 78·3-89·4) and injection site pain (120 [67%]; 224 events, 59·9-73·5); most frequent systemic reactions were headache (80 [45%]; 112 events, 37·6-52·0), excessive fatigue (45 [25%]; 56 events, 19·4-32·0), and myalgia (45 [25%]; 57 events, 19·4-32·0). A similar safety and tolerability profile was observed between adjuvanted and non-adjuvanted formulations. The majority of solicited adverse events were mild or moderate. VLA15 was immunogenic for all OspA serotypes with higher immune responses induced in the adjuvanted higher dose groups (geometric mean titre range 90 μg with alum 61·3 U/mL-321·7 U/mL vs 23·8 U/mL-111·5 U/mL at 90 μg without alum).

INTERPRETATION

This novel multivalent vaccine candidate against Lyme borreliosis was safe and immunogenic and paves the way to further clinical development.

FUNDING

Valneva Austria.

Immune responses in healthy adults elicited by a bivalent norovirus vaccine candidate composed of GI.4 and GII.4 VLPs without adjuvant

The development of an efficacious vaccine against norovirus is of paramount importance given its potential to reduce the global burden of norovirus-associated morbidity and mortality. Here, we report a detailed immunological analysis of a phase I, double-blind, placebo-controlled clinical trial performed on 60 healthy adults, ages 18 to 40. Total serum immunoglobulin and serum IgA against vaccine strains and cross-reactive serum IgG against non-vaccine strains were measured by enzyme immunoassays, whereas cell-mediated immune responses were quantified using intracellular cytokine staining by flow cytometry. A significant increase in humoral and cellular responses, e.g., IgA and CD4⁺ polypositive T cells, was triggered by the GI.4 Chiba 407 (1987) and GII.4 Aomori 2 (2006) VLP-based norovirus vaccine candidate rNV-2v, which is formulated without adjuvant. No booster effect was observed after the second administration in the pre-exposed adult study population. Furthermore, a cross-reactive immune response was elicited, as shown by IgG titers against GI.3 (2002), GII.2 OC08154 (2008), GII.4 (1999), GII.4 Sydney (2012), GII.4 Washington (2018), GII.6 Maryland (2018), and GII.17 Kawasaki 308 (2015). Due to viral infection via mucosal gut tissue and the high variety of potentially relevant norovirus strains, a focus should be on IgA and cross-protective humoral and cell-mediated responses in the development of a broadly protective, multi-valent norovirus vaccine.

Clinical trial registration

https://clinicaltrials.gov, identifier NCT05508178. EudraCT number: 2019-003226-25.

Sanitary installations and wastewater plumbing as reservoir for the long-term circulation and transmission of carbapenemase producing Citrobacter freundii clones in a hospital setting

BACKGROUND

Accumulating evidence shows a role of the hospital wastewater system in the spread of multidrug-resistant organisms, such as carbapenemase producing Enterobacterales (CPE). Several sequential outbreaks of CPE on the geriatric ward of the Ghent University hospital have led to an outbreak investigation. Focusing on OXA-48 producing Citrobacter freundii, the most prevalent species, we aimed to track clonal relatedness using whole genome sequencing (WGS). By exploring transmission routes we wanted to improve understanding and (re)introduce targeted preventive measures.

METHODS

Environmental screening (toilet water, sink and shower drains) was performed between 2017 and 2021. A retrospective selection was made of 53 Citrobacter freundii screening isolates (30 patients and 23 environmental samples). DNA from frozen bacterial isolates was extracted and prepped for shotgun WGS. Core genome multilocus sequence typing was performed with an in-house developed scheme using 3,004 loci.

RESULTS

The CPE positivity rate of environmental screening samples was 19.0% (73/385). Highest percentages were found in the shower drain samples (38.2%) and the toilet water samples (25.0%). Sink drain samples showed least CPE positivity (3.3%). The WGS data revealed long-term co-existence of three patient sample derived C. freundii clusters. The biggest cluster (ST22) connects 12 patients and 8 environmental isolates taken between 2018 and 2021 spread across the ward. In an overlapping period, another cluster (ST170) links eight patients and four toilet water isolates connected to the same room. The third C. freundii cluster (ST421) connects two patients hospitalised in the same room but over a period of one and a half year. Additional sampling in 2022 revealed clonal isolates linked to the two largest clusters (ST22, ST170) in the wastewater collection pipes connecting the rooms.

CONCLUSIONS

Our findings suggest long-term circulation and transmission of carbapenemase producing C. freundii clones in hospital sanitary installations despite surveillance, daily cleaning and intermittent disinfection protocols. We propose a role for the wastewater drainage system in the spread within and between rooms and for the sanitary installations in the indirect transmission via bioaerosol plumes. To tackle this problem, a multidisciplinary approach is necessary including careful design and maintenance of the plumbing system.

Respiratory syncytial virus disease burden in community-dwelling and long-term care facility older adults in Europe and the United States: A prospective study

Respiratory syncytial virus (RSV) causes respiratory illnesses, which can lead to serious complications in older adults. We estimated how common infections due to RSV are in adults living in the community or long-term care facilities. For 2 years, we followed approximately 2000 adults 50 years and older in Europe and the United States. Between October 2019 and March 2020, about 2 in 100 adults in this study had RSV infections; of these, fewer than one fifth had complications and there were no hospitalizations or deaths. Other viruses were present for less than one fifth of RSV infections. Between October 2020 and June 2021, during COVID-19 restrictions, we detected RSV infection in one adult, living in a long-term care facility, with no complications. RSV causes respiratory disease among adults 50 years and older and therefore programs to prevent RSV infection are needed in this age group.

Respiratory Syncytial Virus Prefusion F Protein Vaccine in Older Adults

BACKGROUND

Respiratory syncytial virus (RSV) is an important cause of acute respiratory infection, lower respiratory tract disease, clinical complications, and death in older adults. There is currently no licensed vaccine against RSV infection.

METHODS

In an ongoing, international, placebo-controlled, phase 3 trial, we randomly assigned, in a 1:1 ratio, adults 60 years of age or older to receive a single dose of an AS01_E-adjuvanted RSV prefusion F protein-based candidate vaccine (RSVPreF3 OA) or placebo before the RSV season. The primary objective was to show vaccine efficacy of one dose of the RSVPreF3 OA vaccine against RSV-related lower respiratory tract disease, confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR), during one RSV season. The criterion for meeting the primary objective was a lower limit of the confidence interval around the efficacy estimate of more than 20%. Efficacy against severe RSV-related lower respiratory tract disease and RSV-related acute respiratory infection was assessed, and analyses according to RSV subtype (A and B) were performed. Safety was evaluated.

RESULTS

A total of 24,966 participants received one dose of the RSVPreF3 OA vaccine (12,467 participants) or placebo (12,499). Over a median follow-up of 6.7 months, vaccine efficacy against RT-PCR-confirmed RSV-related lower respiratory tract disease was 82.6% (96.95% confidence interval [CI], 57.9 to 94.1), with 7 cases (1.0 per 1000 participant-years) in the vaccine group and 40 cases (5.8 per 1000 participant-years) in the placebo group. Vaccine efficacy was 94.1% (95% CI, 62.4 to 99.9) against severe RSV-related lower respiratory tract disease (assessed on the basis of clinical signs or by the investigator) and 71.7% (95% CI, 56.2 to 82.3) against RSV-related acute respiratory infection. Vaccine efficacy was similar against the RSV A and B subtypes (for RSV-related lower respiratory tract disease: 84.6% and 80.9%, respectively; for RSV-related acute respiratory infection: 71.9% and 70.6%, respectively). High vaccine efficacy was observed in various age groups and in participants with coexisting conditions. The RSVPreF3 OA vaccine was more reactogenic than placebo, but most adverse events for which reports were solicited were transient, with mild-to-moderate severity. The incidences of serious adverse events and potential immune-mediated diseases were similar in the two groups.

CONCLUSIONS

A single dose of the RSVPreF3 OA vaccine had an acceptable safety profile and prevented RSV-related acute respiratory infection and lower respiratory tract disease and severe RSV-related lower respiratory tract disease in adults 60 years of age or older, regardless of RSV subtype and the presence of underlying coexisting conditions. (Funded by GlaxoSmithKline Biologicals; AReSVi-006 ClinicalTrials.gov number, NCT04886596.).

Double-Blind, Placebo-Controlled, Dose-Escalating Study Evaluating the Safety and Immunogenicity of an Epitope-Specific Chemically Defined Nanoparticle RSV Vaccine

BACKGROUND

V-306 is a virus-like particle-based vaccine candidate displaying respiratory syncytial virus (RSV) F site II protein mimetics (FsIIm) as an antigenic epitope.

METHODS

This was a randomized, placebo-controlled, double-blind, dose-escalating, first-in-human study, conducted in 60 women aged 18-45 years. Twenty subjects per cohort (15 vaccine and five placebo) received two V-306 intramuscular administrations on Days 0 and 56 at 15 µg, 50 µg, or 150 µg. Safety and immunogenicity were assessed after each vaccination and for 1 year in total.

RESULTS

V-306 was safe and well tolerated at all dose levels, with no increase in reactogenicity and unsolicited adverse events between the first and second administrations. At 50 µg and 150 µg, V-306 induced an increase in FsIIm-specific immunoglobulin G (IgG) titers, which lasted at least 4 months. This did not translate into an increase in RSV-neutralizing antibody titers, which were already high at baseline. No increase in the anti-F protein-specific IgG titers was observed, which were also high in most subjects at baseline due to past natural infections.

CONCLUSIONS

V-306 was safe and well-tolerated. Future modifications of the vaccine and assay conditions will likely improve the results of vaccination.

Human Immunity and Susceptibility to Influenza A(H3) Viruses of Avian, Equine, and Swine Origin

Influenza A viruses (IAVs) of subtype H3 that infect humans are antigenically divergent from those of birds, horses, and swine. Human immunity against these viruses might be limited, implying potential pandemic risk. To determine human risk, we selected 4 avian, 1 equine, and 3 swine IAVs representing major H3 lineages. We tested serum collected during 2017-2018 from 286 persons in Belgium for hemagglutination inhibiting antibodies and virus neutralizing antibodies against those animal-origin IAVs and tested replication in human airway epithelia. Seroprevalence rates for circulating IAVs from swine in North America were >51%, swine in Europe 7%-37%, and birds and equids ≤12%. Replication was efficient for cluster IV-A IAVs from swine in North America and IAVs from swine in Europe, intermediate for IAVs from horses and poultry, and absent for IAVs from wild birds and a novel human-like swine IAV in North America. Public health risk may be highest for swine H3 IAVs.

LB745. Respiratory Syncytial Virus (RSV) Prefusion F Protein Candidate Vaccine (RSVPreF3 OA) is Efficacious in Adults ≥ 60 Years of Age (YOA)

Background

RSV-associated acute respiratory infections (ARI), particularly lower respiratory tract diseases (LRTD), present a significant disease burden in older adults. Currently, there are no approved vaccines against RSV. We present results from an ongoing study designed to demonstrate the vaccine efficacy (VE) of the AS01_E-adjuvanted RSVPreF3 OA in adults ≥ 60 YOA.

Methods

This ongoing, phase 3, observer-blind, placebo-controlled, multi-country study (NCT04886596) enrolled adults ≥ 60 YOA from the northern and southern hemispheres. Participants were randomized (1:1) to receive a single dose of RSVPreF3 OA or placebo before the RSV season. The primary objective was to demonstrate VE of a single dose of RSVPreF3 OA in preventing RSV-confirmed LRTD during one RSV season (criterion: lower limit of VE confidence interval [CI] > 20%). VE is reported also against severe RSV-confirmed LRTD, RSV-confirmed ARI, RSV-confirmed LRTD and RSV-confirmed ARI by RSV subtype (RSV-A and RSV-B), and RSV-confirmed LRTD by age, baseline comorbidity and frailty status. RSV-A/B was confirmed by quantitative RT-PCR.

Results

A total of 26,664 participants were enrolled, of whom 24,966 (RSVPreF3 OA: 12,467; placebo: 12,499) were included in the exposed set and 24,960 (RSVPreF3 OA: 12,466; placebo: 12,494) in the efficacy analysis. The mean age was 69.5 (±6.5) years and 51.7% were women. Over a median follow-up of 6.7 months (maximum 10.1 months), 47 RSV-confirmed LRTD episodes were reported (RSVPreF3 OA: 7; placebo: 40), resulting in a VE of 82.6% (96.95% CI: 57.9–94.1), thus the primary objective was met. Consistently high VE across the clinical spectrum of RSV disease, from RSV-confirmed ARI (71.7% [95% CI: 56.2–82.3]) to severe RSV-confirmed LRTD (94.1% [95% CI: 62.4–99.9]) was observed. High VE was seen in different age groups and regardless of RSV subtype, baseline comorbidity or pre-frail status (Figure 1). Cumulative incidence curves for RSV-confirmed LRTD and RSV-confirmed ARI showed persistent efficacy throughout the follow-up (Figure 2).

Conclusion

A single RSVPreF3 OA dose is highly efficacious against RSV-confirmed LRTD and RSV-confirmed ARI in adults ≥ 60 YOA, regardless of RSV disease severity, RSV subtype, baseline comorbidity and pre-frail status.

Funding: GlaxoSmithKline Biologicals SA.

Abstract and information is also available at the following link : Efficacy results for GSK's older adult RSV vaccine (investis.com).

Disclosures

Michael G. Ison, MD MS, GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support Alberto Papi, MD, CHIESI, ASTRAZENECA, GSK, BI, MENARINI, NOVARTIS, ZAMBON, MUNDIPHARMA, SANOFI, AVILLION: Honoraria|CHIESI, ASTRAZENECA, GSK, NOVARTIS, SANOFI, IQVIA, AVILLION, ELPEN PHARMACEUTICALS: Advisor/Consultant|CHIESI, ASTRAZENECA, GSK, NOVARTIS, SANOFI, IQVIA, AVILLION, ELPEN PHARMACEUTICALS: Board Member|CHIESI, ASTRAZENECA, GSK, SANOFI: Grant/Research Support Joanne M. Langley, MD, GSK, Merck, Medicago, Sanofi, VBI, VIDO, Entos, Pfizer: Grant/Research Support Isabel Leroux-Roels, PhD MD, Curevac: payment to my institution for the conduct of clinical trials|GSK: payment to my institution for the conduct of clinical trials|ICON Genetics: payment to my institution for the conduct of clinical trials|Janssen Vaccines (J&J): Board Member|Janssen Vaccines (J&J): payment to my institution for the conduct of clinical trials|Osivax: payment to my institution for the conduct of clinical trials Federico Martinon-Torres, MD, PhD, Assoc. Prof, GlaxoSmithKline, Pfizer, Sanofi, Merck, Moderna, Astra Zeneca, Biofabri, Janssen, Novavax: Advisor/Consultant|GlaxoSmithKline, Pfizer, Sanofi, Merck, Moderna, Astra Zeneca, Biofabri, Janssen, Novavax: Grant/Research Support|GlaxoSmithKline, Pfizer, Sanofi, Merck, Moderna, Astra Zeneca, Biofabri, Janssen, Novavax: Honoraria|GlaxoSmithKline, Pfizer, Sanofi, Merck, Moderna, Astra Zeneca, Biofabri, Janssen, Novavax: Clínical trials fees paid to my institution Tino F. Schwarz, Prof. Dr. MD, GlaxoSmithKline: Advisor/Consultant Richard N. Van Zyl-Smit, PhD MD, MSD, Pfizer, GSK, Astra Zeneca, Roche, Novartis, Boehringer Ingelheim, Cipla, J&J, Glenmark: Advisor/Consultant|MSD, Pfizer, GSK, Astra Zeneca, Roche, Novartis, Boehringer Ingelheim, Cipla, J&J, Glenmark: Honoraria Nancy Dezutter, PhD, PharmD, GlaxoSmithKline: GSK employee|GlaxoSmithKline: Stocks/Bonds Nathalie De Schrevel, PhD, GlaxoSmithKline: GSK employee Laurence Fissette, Master in Statistics, GlaxoSmithKline: GSK employee|GlaxoSmithKline: Stocks/Bonds Marie-Pierre David, Master in Statistics, GlaxoSmithKline: GSK employee|GlaxoSmithKline: Stocks/Bonds Marie Van Der Wielen, MD, GlaxoSmithKline: GSK employee|GlaxoSmithKline: Stocks/Bonds Lusine Kostanyan, MD, GlaxoSmithKline: GSK employee|GlaxoSmithKline: Stocks/Bonds Veronica Hulstrøm, PhD MD, GlaxoSmithKline: GSK employee.

A randomized, double-blind, placebo-controlled, dose-escalating phase I trial to evaluate safety and immunogenicity of a plant-produced, bivalent, recombinant norovirus-like particle vaccine

Noroviruses (NoV) are the leading cause of epidemic acute gastroenteritis in humans worldwide and a safe and effective vaccine is needed. Here, a phase I, double-blind, placebo-controlled clinical trial was performed in 60 healthy adults, 18 to 40 years old. Safety (primary objective) and immunogenicity (secondary and exploratory objectives) of a bivalent (GI.4 and GII.4), plant-produced, virus-like particle (VLP), NoV vaccine candidate formulation were investigated at two dose levels (50 µg + 50 µg and 150 µg + 150 µg) without adjuvant. Overall, 13 subjects (65.0%) in the 50 µg group, 16 subjects (80.0%) in the 150 µg group, and 14 subjects (70.0%) in the placebo group reported at least 1 solicited local or general symptom during the 7-day post-vaccination periods following each dose. Severe solicited adverse events (AEs) were rare (2 events in the 50 µg group). A total of 8 subjects (40.0%) in each group reported at least one unsolicited AE during the 28-day post-vaccination periods. Immunogenicity was assessed on days 1, 8, 29, 57, 183 and 365. All subjects were pre-exposed to norovirus as indicated by baseline levels of the different immunological parameters examined. Vaccine-specific humoral and cellular immune responses increased after the first dose but did not rise further after the second vaccination. Increased GI.4- and GII.4-specific IgG titers persisted until day 365. The vaccine elicited cross-reactive IgG antibodies against non-vaccine NoV VLPs, which was more pronounced for NoV strains of the same genotype as the GII.4 vaccine strain than for non-vaccine genotypes. Significant blocking anti-GI.4 and anti-GII.4 VLP titers were triggered in both dose groups. Lymphoproliferation assays revealed strong cell-mediated immune responses that persisted until day 365. In conclusion, both dose levels were safe and well-tolerated, and no higher incidence of AEs was observed in the higher dose group. The data show that a single dose of the vaccine formulated at 50 µg of each VLP is sufficient to reach a peak immune response after 8 to 28 days. The results of this Phase I study warrant further evaluation of the non-adjuvanted vaccine candidate.

Practice testing of generic quality indicators for responsible antibiotic use in 9 hospitals in the Dutch-Belgian border area

BACKGROUND

Inpatient quality indicators (IQIs) were previously developed to assess responsible antibiotic use. The aim of this study was the practice testing of these QIs in the hospital setting.

METHOD

This study was performed within a Dutch-Belgian border network of hospitals implementing the Infection Risk Scan (IRIS) point prevalence survey (PPS) as part of the I-4-1-Health project. Twenty out of 51 DRIVE-AB IQIs, including 13 structure and 7 process IQIs, were tested. Data on structure IQIs were obtained through a web-based questionnaire sent to the hospital medical microbiologists. PPS data from October-December 2018 were used to calculate performance scores for the process QIs.

RESULTS

Nine hospitals participated. Regarding structure IQIs: the lowest performance scores were observed for recommendations for microbiological investigations in the guidelines and the use of an approval system for restricted antibiotics. In addition, most hospitals reported that some antibiotics were out of stock due to shortages. Regarding process IQIs: 697 systemic antibiotic prescriptions were used to calculate performance scores. The lowest score was observed for documentation of an antibiotic plan in the medical file (58.8%). Performance scores for IQIs on guideline compliance varied between 74.1% and 82.3% for different aspects of the antibiotic regimen (duration, choice, route, timing).

CONCLUSION

This multicentre practice testing of IQIs identified improvement targets for stewardship efforts for both structure and process aspects of antibiotic care (approval system for restricted antibiotics, documentation of antibiotic plan). These results can guide the design of future PPS studies and a more extensive evaluation of the clinimetric properties of the IQIs.

The role of cell-mediated immunity against influenza and its implications for vaccine evaluation

Influenza vaccines remain the most effective tools to prevent flu and its complications. Trivalent or quadrivalent inactivated influenza vaccines primarily elicit antibodies towards haemagglutinin and neuraminidase. These vaccines fail to induce high protective efficacy, in particular in older adults and immunocompromised individuals and require annual updates to keep up with evolving influenza strains (antigenic drift). Vaccine efficacy declines when there is a mismatch between its content and circulating strains. Current correlates of protection are merely based on serological parameters determined by haemagglutination inhibition or single radial haemolysis assays. However, there is ample evidence showing that these serological correlates of protection can both over- or underestimate the protective efficacy of influenza vaccines. Next-generation universal influenza vaccines that induce cross-reactive cellular immune responses (CD4+ and/or CD8+ T-cell responses) against conserved epitopes may overcome some of the shortcomings of the current inactivated vaccines by eliciting broader protection that lasts for several influenza seasons and potentially enhances pandemic preparedness. Assessment of cellular immune responses in clinical trials that evaluate the immunogenicity of these new generation vaccines is thus of utmost importance. Moreover, studies are needed to examine whether these cross-reactive cellular immune responses can be considered as new or complementary correlates of protection in the evaluation of traditional and next-generation influenza vaccines. An overview of the assays that can be applied to measure cell-mediated immune responses to influenza with their strengths and weaknesses is provided here.

Safety and immunogenicity of a respiratory syncytial virus prefusion F (RSVPreF3) candidate vaccine in older adults: phase I/II randomized clinical trial

BACKGROUND

The aim was to investigate safety and immunogenicity of vaccine formulations against respiratory syncytial virus (RSV) containing the stabilized prefusion conformation of RSV fusion protein (RSVPreF3).

METHODS

This phase I/II, randomized, controlled, observer-blind study enrolled 48 young adults (YA; 18-40 years) and 1005 older adults (OA; 60-80 years) between January and August 2019. Participants were randomized into equally sized groups to receive two doses of unadjuvanted (YA and OA) or AS01-adjuvanted (OA) vaccine or placebo two months apart. Vaccine safety and immunogenicity were assessed until one (YA) or 12 months (OA) after second vaccination.

RESULTS

The RSVPreF3 vaccines boosted humoral (RSVPreF3-specific IgG and RSV-A neutralizing antibody) responses, which increased in an antigen-concentration-dependent manner and were highest post-dose one. Compared to pre-vaccination, the geometric mean frequencies of polyfunctional CD4+ T-cells increased after each dose and were significantly higher in adjuvanted than unadjuvanted vaccinees. Post-vaccination immune responses persisted until end of follow-up. Solicited adverse events (AEs) were mostly mild-to-moderate and transient. Despite a higher observed reactogenicity of AS01-containing vaccines, no safety concerns were identified for any assessed formulation.

CONCLUSIONS

Based on safety and immunogenicity profiles, the AS01E-adjuvanted vaccine containing 120 μg of RSVPreF3 was selected for further clinical development.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03814590; URL: https://clinicaltrials.gov/ct2/show/NCT03814590.

Randomized, Double-Blind, Reference-Controlled, Phase 2a Study Evaluating the Immunogenicity and Safety of OVX836, A Nucleoprotein-Based Influenza Vaccine

OVX836 is a recombinant protein-based vaccine targeting the highly conserved influenza nucleoprotein (NP), which aims to confer a broad-spectrum protection against influenza. In a Phase 1 study, OVX836, administered intramuscularly, has been found safe and immunogenic. The 90µg and 180µg dose levels were selected to be further evaluated in this randomized, monocenter, reference-controlled (Influvac Tetra™: quadrivalent seasonal influenza subunit vaccine), parallel group, double-blind, Phase 2a study in 300 healthy volunteers, aged 18-65 years, during the 2019/2020 flu season. Safety, influenza-like illness episodes (ILI; based on the Flu-PRO^® questionnaire) and immunogenicity were assessed up to 180 days post-vaccination. OVX836 was safe and presented a reactogenicity profile similar to Influvac Tetra. It induced a significant increase in terms of NP-specific interferon-gamma (IFNγ) spot forming cells (SFCs), NP-specific CD4+ T-cells (essentially polyfunctional cells) and anti-NP IgG responses. OVX836 was superior to Influvac Tetra for all immunological parameters related to NP, and the 180µg dose was significantly superior to the 90µg dose for SFCs and CD4+ T-cells expressing IFNγ. Both the CD4+ T-cell and the anti-NP IgG responses persisted up to Day 180. An efficacy signal was observed with OVX836 at 180µg through reduction of ILI episodes occurring during the flu season as of 14 days post-vaccination. In conclusion, these results encourage further clinical evaluation of OVX836 in order to confirm the signal of efficacy on ILIs and/or laboratory-confirmed influenza cases. NCT04192500 (https://clinicaltrials.gov/ct2/show/study/NCT04192500).

Efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate in ten countries in Europe and Latin America (HERALD): a randomised, observer-blinded, placebo-controlled, phase 2b/3 trial

BACKGROUND

Additional safe and efficacious vaccines are needed to control the COVID-19 pandemic. We aimed to analyse the efficacy and safety of the CVnCoV SARS-CoV-2 mRNA vaccine candidate.

METHODS

HERALD is a randomised, observer-blinded, placebo-controlled, phase 2b/3 clinical trial conducted in 47 centres in ten countries in Europe and Latin America. By use of an interactive web response system and stratification by country and age group (18-60 years and ≥61 years), adults with no history of virologically confirmed COVID-19 were randomly assigned (1:1) to receive intramuscularly either two 0·6 mL doses of CVnCoV containing 12 μg of mRNA or two 0·6 mL doses of 0·9% NaCl (placebo) on days 1 and 29. The primary efficacy endpoint was the occurrence of a first episode of virologically confirmed symptomatic COVID-19 of any severity and caused by any strain from 15 days after the second dose. For the primary endpoint, the trial was considered successful if the lower limit of the CI was greater than 30%. Key secondary endpoints were the occurrence of a first episode of virologically confirmed moderate-to-severe COVID-19, severe COVID-19, and COVID-19 of any severity by age group. Primary safety outcomes were solicited local and systemic adverse events within 7 days after each dose and unsolicited adverse events within 28 days after each dose in phase 2b participants, and serious adverse events and adverse events of special interest up to 1 year after the second dose in phase 2b and phase 3 participants. Here, we report data up to June 18, 2021. The study is registered at ClinicalTrials.gov, NCT04652102, and EudraCT, 2020-003998-22, and is ongoing.

FINDINGS

Between Dec 11, 2020, and April 12, 2021, 39 680 participants were enrolled and randomly assigned to receive either CVnCoV (n=19 846) or placebo (n=19 834), of whom 19 783 received at least one dose of CVnCoV and 19 746 received at least one dose of placebo. After a mean observation period of 48·2 days (SE 0·2), 83 cases of COVID-19 occurred in the CVnCoV group (n=12 851) in 1735·29 person-years and 145 cases occurred in the placebo group (n=12 211) in 1569·87 person-years, resulting in an overall vaccine efficacy against symptomatic COVID-19 of 48·2% (95·826% CI 31·0-61·4; p=0·016). Vaccine efficacy against moderate-to-severe COVID-19 was 70·7% (95% CI 42·5-86·1; CVnCoV 12 cases in 1735·29 person-years, placebo 37 cases in 1569·87 person-years). In participants aged 18-60 years, vaccine efficacy against symptomatic disease was 52·5% (95% CI 36·2-64·8; CVnCoV 71 cases in 1591·47 person-years, placebo, 136 cases in 1449·23 person-years). Too few cases occurred in participants aged 61 years or older (CVnCoV 12, placebo nine) to allow meaningful assessment of vaccine efficacy. Solicited adverse events, which were mostly systemic, were more common in CVnCoV recipients (1933 [96·5%] of 2003) than in placebo recipients (1344 [67·9%] of 1978), with 542 (27·1%) CVnCoV recipients and 61 (3·1%) placebo recipients reporting grade 3 solicited adverse events. The most frequently reported local reaction after any dose in the CVnCoV group was injection-site pain (1678 [83·6%] of 2007), with 22 grade 3 reactions, and the most frequently reported systematic reactions were fatigue (1603 [80·0%] of 2003) and headache (1541 [76·9%] of 2003). 82 (0·4%) of 19 783 CVnCoV recipients reported 100 serious adverse events and 66 (0·3%) of 19 746 placebo recipients reported 76 serious adverse events. Eight serious adverse events in five CVnCoV recipients and two serious adverse events in two placebo recipients were considered vaccination-related. None of the fatal serious adverse events reported (eight in the CVnCoV group and six in the placebo group) were considered to be related to study vaccination. Adverse events of special interest were reported for 38 (0·2%) participants in the CVnCoV group and 31 (0·2%) participants in the placebo group. These events were considered to be related to the trial vaccine for 14 (<0·1%) participants in the CVnCoV group and for five (<0·1%) participants in the placebo group.

INTERPRETATION

CVnCoV was efficacious in the prevention of COVID-19 of any severity and had an acceptable safety profile. Taking into account the changing environment, including the emergence of SARS-CoV-2 variants, and timelines for further development, the decision has been made to cease activities on the CVnCoV candidate and to focus efforts on the development of next-generation vaccine candidates.

FUNDING

German Federal Ministry of Education and Research and CureVac.

Feedback of ATP measurement as a tool for reducing environmental contamination in hospitals in the Dutch/Belgian border area

DESIGN

A two-phase prospective intervention study.

OBJECTIVE

The objective of this study was to determine if feedback of adenosine triphosphate (ATP) measurements decreases environmental contamination within hospitals in the Dutch/Belgian border area.

METHODS

Standardized ATP measurements were conducted in nine hospitals on pre-defined fomites. Four different fomite groups were defined: medical devices, patient-bound materials, ward-bound materials and sanitary items. ATP results were reported in relative light unit (RLU), RLU >1000 was considered as 'not clean.' Two rounds of ATP measurements were conducted. After the first round of ATP measurements, results were provided to the wards and cleaning staff. The second round of ATP measurements was performed one year later. The amount of surface contamination before and after the feedback was compared.

RESULTS

In total 1923 ATP measurements were performed. Before feedback 960 ATP measurements were conducted and after feedback 963 were conducted. The overall median reduction in RLU was 381 (P < 0.001), from 568 before feedback to 187 afterward. In each hospital there was a reduction of the median RLU after feedback.

CONCLUSIONS

Substantial reductions in RLU values were found after feedback of ATP measurements. Feedback of ATP measurement in itself was associated with a major reduction of surface contamination in hospitals.

A new fully liquid presentation of MenACWY-CRM conjugate vaccine: Results from a multicentre, randomised, controlled, observer-blind study

BACKGROUND

The currently licensed quadrivalent MenACWY-CRM conjugate vaccine presentation consists of two vials (lyophilised MenA and liquid MenCWY) to be reconstituted before injection. A new fully liquid formulation in a single vial has been developed to further improve the vaccine presentation. Since the MenA structure is subject to hydrolytic degradation, this study was conducted to compare the immunogenicity and safety of the investigational MenACWY-CRM liquid vaccine with the licensed vaccine.

METHODS

In this multicentre, randomised, controlled, observer-blind, phase 2b study, 979 healthy adults were administered a single dose of MenACWY-CRM liquid presentation or the currently licensed MenACWY-CRM vaccine. MenA free saccharide generation was accelerated to approximately 30% in the liquid presentation and MenA polysaccharide O-acetylation was reduced to approximately 40%, according to a controlled procedure. Immunological non-inferiority of the MenACWY-CRM liquid to the licensed vaccine, as measured by human serum bactericidal assay (hSBA) geometric mean titres (GMTs) against MenA 1 month post-vaccination, was the primary study objective. Safety assessment was among the secondary objectives.

RESULTS

Immune responses against each serogroup were similar between the two vaccine groups and was non-inferior for MenA. Adjusted hSBA GMTs for MenA were 185.16 and 211.33 for the MenACWY-CRM liquid presentation and currently licensed vaccine presentation, respectively. The between-group ratio of hSBA GMTs for MenA was 0.88, with a two-sided 95% confidence interval lower limit of 0.64, greater than the prespecified non-inferiority margin of 0.5, thus meeting the primary study objective. Both vaccines were well tolerated. No serious adverse events were considered related to vaccination.

CONCLUSIONS

The levels of MenA free saccharide and polysaccharide O-acetylation did not affect the immunogenicity of the fully liquid presentation, which was demonstrated to be non-inferior to the immunogenicity of the currently licensed MenACWY-CRM vaccine against MenA. The immunogenicity, reactogenicity and safety profiles of the two vaccine presentations were similar.

Immunogenicity and safety of a quadrivalent high-dose inactivated influenza vaccine compared with a standard-dose quadrivalent influenza vaccine in healthy people aged 60 years or older: a randomized Phase III trial

A quadrivalent high-dose inactivated influenza vaccine (IIV4-HD) is licensed for adults ≥65 y of age based on immunogenicity and efficacy studies. However, IIV4-HD has not been evaluated in adults aged 60–64 y. This study compared immunogenicity and safety of IIV4-HD with a standard-dose quadrivalent influenza vaccine (IIV4-SD) in adults aged ≥60 y. This Phase III, randomized, modified double-blind, active-controlled study enrolled 1,528 participants aged ≥60 y, randomized 1:1 to a single injection of IIV4-HD or IIV4-SD. Hemagglutination inhibition (HAI) geometric mean titers (GMTs) were measured at baseline and D 28 and seroconversion assessed. Safety was described for 180 d after vaccination. The primary immunogenicity objective was superiority of IIV4-HD versus IIV4-SD, for all four influenza strains 28 d post vaccination in participants aged 60–64 and ≥65 y. IIV4-HD induced a superior immune response versus IIV4-SD in terms of GMTs in participants aged 60–64 y and those aged ≥65 y for all four influenza strains. IIV4-HD induced higher GMTs in those aged 60–64 y than those aged ≥65 y. Seroconversion rates were higher for IIV4-HD versus IIV4-SD in each age-group for all influenza strains. Both vaccines were well tolerated in participants ≥60 y of age, with no safety concerns identified. More solicited reactions were reported with IIV4-HD than with IIV4-SD. IIV4-HD provided superior immunogenicity versus IIV4-SD and was well tolerated in adults aged ≥60 y. IIV4-HD is assumed to offer improved protection against influenza compared with IIV4-SD in adults aged ≥60 y, as was previously assessed for adults aged ≥65 y.

Immunogenicity and Safety of a 3-Antigen Hepatitis B Vaccine vs a Single-Antigen Hepatitis B Vaccine: A Phase 3 Randomized Clinical Trial

IMPORTANCE

There is a need for improved immunogenicity of hepatitis B virus (HBV) vaccines among young adults with risk of infection.

OBJECTIVES

To demonstrate manufacturing equivalence of a 3-antigen (3A) HBV vaccine, evaluate noninferiority of seroprotection rate (SPR) of 3A-HBV vs single-antigen (1A) HBV after 2 and 3 vaccine doses, and compare safety and reactogenicity between 3A-HBV and 1A-HBV vaccines.

DESIGN, SETTING, AND PARTICIPANTS

This phase 3, double-blinded, randomized clinical trial included healthy adults aged 18 to 45 years randomized to 1 of three 3A-HBV groups or 1 control group receiving 1A-HBV. The trial was conducted at 37 community clinics and academic hospitals in Canada, Europe, the United Kingdom, and the United States between December 2017 and October 2019. Participants were followed up for 48 weeks after the first vaccination.

INTERVENTIONS

Intramuscular administration of 3A-HBV (10 μg) or 1A-HBV (20 μg) on days 0, 28, and 168.

MAIN OUTCOMES AND MEASURES

Geometric mean concentration (GMC) of serum hepatitis B surface antibodies (anti-HBs) and proportion of participants achieving seroprotection.

RESULTS

Of 2838 participants, 1638 (57.8%) were women, 2595 (91.5%) were White, and 161 (5.7%) were Black or African American. A total of 712 participants (25.1%) were randomized to the 1A-HBV group and 2126 (74.9%) to 3A-HBV. The mean (SD) age at informed consent was 33.5 (8.0) years. The study demonstrated 3A-HBV lot-to-lot consistency, as the 2-sided 95% CIs for each pairwise comparison for the anti-HBs GMC ratios were within 0.67 and 1.50 (eg, adjusted GMC ratio, lot A vs lot B: 0.82; 95% CI, 0.67-1.00; lot A vs lot C: 0.95; 95% CI, 0.78-1.15; lot B vs lot C: 1.16; 95% CI, 0.95-1.41). The SPR of the pooled 3A-HBV was noninferior to 1A-HBV and higher than 1A-HBV after 2 vaccinations at day 168 (90.4% [95% CI, 89.0%-91.8%] vs 51.6% [95% CI, 47.5%-55.6%]) and 3 vaccinations at day 196 (99.3% [95% CI, 98.7%-99.6%] vs 94.8% [95% CI, 92.7%-96.4%]). The mean GMC of anti-HBs with 3A-HBV was 7.9 times higher after 2 vaccinations at day 168 and 3.5 times higher after 3 vaccinations at day 196 compared with 1A-HBV (after 2 vaccinations, 3A-HBV: GMC, 118.7 mIU/mL; 95% CI, 108.0-129.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: GMC, 15.0 mIU/mL; 95% CI, 12.9-17.5 mIU/mL; SE, 1.0 mIU/mL; after 3 vaccinations, 3A-HBV: GMC, 5442.4 mIU/mL; 95% CI, 4967.0-5963.0 mIU/mL; SE, 1.0 mIU/mL; 1A-HBV: 1567.2 mIU/mL; 95% CI, 1338.0-1834.0 mIU/mL; SE, 1.0 mIU/mL). Rates of local and systemic reactogenicities were higher with 3A-HBV compared with 1A-HBV (local: 1805 of 2124 [85.0%] vs 469 of 712 [65.9%]; systemic: 1445 [68.0%] vs 428 [60.1%]). Vaccine discontinuation due to adverse events (AE) was uncommon, and serious AEs were infrequent, reported in 42 participants (2.0%) and 3 participants (0.4%) in the 3A-HBV and 1A-HBV groups, respectively.

CONCLUSIONS AND RELEVANCE

In this study, consistently higher antibody concentrations and SPRs were found with 3A-HBV after 2 and 3 doses vs 1A-HBV in adults aged 18 to 45 years old. The safety and efficacy of 3A-HBV shows its usefulness for the prevention of hepatitis B in young healthy adults.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT03408730; EU Clinical Trials Number: 2017-001820-22.

Safety and immunogenicity of an mRNA-lipid nanoparticle vaccine candidate against SARS-CoV-2 : A phase 1 randomized clinical trial

BACKGROUND

We used the RNActive® technology platform (CureVac N.V., Tübingen, Germany) to prepare CVnCoV, a COVID-19 vaccine containing sequence-optimized mRNA coding for a stabilized form of SARS-CoV‑2 spike (S) protein encapsulated in lipid nanoparticles (LNP).

METHODS

This is an interim analysis of a dosage escalation phase 1 study in healthy 18-60-year-old volunteers in Hannover, Munich and Tübingen, Germany, and Ghent, Belgium. After giving 2 intramuscular doses of CVnCoV or placebo 28 days apart we assessed solicited local and systemic adverse events (AE) for 7 days and unsolicited AEs for 28 days after each vaccination. Immunogenicity was measured as enzyme-linked immunosorbent assay (ELISA) IgG antibodies to SARS-CoV‑2 S‑protein and receptor binding domain (RBD), and SARS-CoV‑2 neutralizing titers (MN50).

RESULTS

In 245 volunteers who received 2 CVnCoV vaccinations (2 μg, n = 47, 4 μg, n = 48, 6 μg, n = 46, 8 μg, n = 44, 12 μg, n = 28) or placebo (n = 32) there were no vaccine-related serious AEs. Dosage-dependent increases in frequency and severity of solicited systemic AEs, and to a lesser extent local AEs, were mainly mild or moderate and transient in duration. Dosage-dependent increases in IgG antibodies to S‑protein and RBD and MN50 were evident in all groups 2 weeks after the second dose when 100% (23/23) seroconverted to S‑protein or RBD, and 83% (19/23) seroconverted for MN50 in the 12 μg group. Responses to 12 μg were comparable to those observed in convalescent sera from known COVID-19 patients.

CONCLUSION

In this study 2 CVnCoV doses were safe, with acceptable reactogenicity and 12 μg dosages elicited levels of immune responses that overlapped those observed in convalescent sera.

Comparison of five SARS-CoV-2 rapid antigen detection tests in a hospital setting and performance of one antigen assay in routine practice: a useful tool to guide isolation precautions?

BACKGROUND

In a hospital setting, there is a need for rapid detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) to guide isolation measures and targeted admission.

AIM

To evaluate the diagnostic performance of five SARS-CoV-2 rapid nucleocapsid protein antigen detection (RAD) assays (Biosynex, Biotical, Orient Gene, Panbio and SD Biosensor), and describe the performance and impact of implementation of the SD Biosensor assay in an emergency department.

METHODS

Sensitivity and specificity of the five RAD assays were analysed on 100 respiratory samples: 60 real-time reverse transcriptase polymerase chain reaction (rRT-PCR)-confirmed SARS-CoV-2-positive samples, 24 SARS-CoV-2 RNA-negative samples and 16 samples positive for other respiratory pathogens. The manufacturer's protocol was adapted to validate the antigen tests on transport media used for rRT-PCR in the authors' routine practice. The SD Biosensor RAD assay was implemented as a screening method for rapid diagnosis and targeted admission.

FINDINGS

Sensitivity of the five RAD assays ranged from 88.9% to 100% for samples with cycle threshold values <26, and specificity ranged from 46.2% to 100%. During the implementation period, 4195 RAD tests were performed. Due to the rapid RAD result, 157 patients were transferred directly to the coronavirus disease 2019 (COVID-19) cohort ward instead of the regular ward (N=47) or the temporary COVID-19 ward (N=110).

CONCLUSION

The SD Biosensor, Biotical and Panbio SARS-CoV-2 antigen tests showed acceptable overall performance, and identified the majority of contagious patients. In the context of high prevalence of SARS-CoV-2, RAD tests can be used as a rapid screening tool to guide infection prevention measures and aid targeted admission.

Detection of H1 Swine Influenza A Virus Antibodies in Human Serum Samples by Age Group1

Most H1 influenza A viruses (IAVs) of swine are derived from past human viruses. As human population immunity against these IAVs gradually decreases, the risk of reintroduction to humans increases. We examined 549 serum samples from persons 0-97 years of age collected in Belgium during 2017-2018 for hemagglutination inhibiting and virus neutralizing antibodies against 7 major H1 swine IAV (swIAV) clades and 3 human progenitor IAVs. Seroprevalence (titers >40) rates were >50% for classical swine and European human-like swIAVs, >24% for North American human-like δ1a and Asian avian-like swIAVs, and <10% for North American human-like δ1b and European avian-like swIAVs, but rates were age-dependent. Antibody titers against human-like swIAVs and supposed human precursor IAVs correlated with correlation coefficients of 0.30-0.86. Our serologic findings suggest that European avian-like, clade 1C.2.1, and North American human-like δ1b, clade 1B.2.2.2, H1 swIAVs pose the highest pandemic risk.

Interim Results of a Phase 1-2a Trial of Ad26.COV2.S Covid-19 Vaccine

BACKGROUND

Efficacious vaccines are urgently needed to contain the ongoing coronavirus disease 2019 (Covid-19) pandemic of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A candidate vaccine, Ad26.COV2.S, is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector encoding a full-length and stabilized SARS-CoV-2 spike protein.

METHODS

In this multicenter, placebo-controlled, phase 1-2a trial, we randomly assigned healthy adults between the ages of 18 and 55 years (cohort 1) and those 65 years of age or older (cohort 3) to receive the Ad26.COV2.S vaccine at a dose of 5×1010 viral particles (low dose) or 1×1011 viral particles (high dose) per milliliter or placebo in a single-dose or two-dose schedule. Longer-term data comparing a single-dose regimen with a two-dose regimen are being collected in cohort 2; those results are not reported here. The primary end points were the safety and reactogenicity of each dose schedule.

RESULTS

After the administration of the first vaccine dose in 805 participants in cohorts 1 and 3 and after the second dose in cohort 1, the most frequent solicited adverse events were fatigue, headache, myalgia, and injection-site pain. The most frequent systemic adverse event was fever. Systemic adverse events were less common in cohort 3 than in cohort 1 and in those who received the low vaccine dose than in those who received the high dose. Reactogenicity was lower after the second dose. Neutralizing-antibody titers against wild-type virus were detected in 90% or more of all participants on day 29 after the first vaccine dose (geometric mean titer [GMT], 212 to 354), regardless of vaccine dose or age group, and reached 96% by day 57 with a further increase in titers (GMT, 288 to 488) in cohort 1a. Titers remained stable until at least day 71. A second dose provided an increase in the titer by a factor of 2.6 to 2.9 (GMT, 827 to 1266). Spike-binding antibody responses were similar to neutralizing-antibody responses. On day 15, CD4+ T-cell responses were detected in 76 to 83% of the participants in cohort 1 and in 60 to 67% of those in cohort 3, with a clear skewing toward type 1 helper T cells. CD8+ T-cell responses were robust overall but lower in cohort 3.

CONCLUSIONS

The safety and immunogenicity profiles of Ad26.COV2.S support further development of this vaccine candidate. (Funded by Johnson & Johnson and the Biomedical Advanced Research and Development Authority of the Department of Health and Human Services; COV1001 ClinicalTrials.gov number, NCT04436276.).

Interim Results of a Phase 1-2a Trial of Ad26.COV2.S Covid-19 Vaccine

BACKGROUND

Efficacious vaccines are urgently needed to contain the ongoing coronavirus disease 2019 (Covid-19) pandemic of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A candidate vaccine, Ad26.COV2.S, is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector encoding a full-length and stabilized SARS-CoV-2 spike protein.

METHODS

In this multicenter, placebo-controlled, phase 1-2a trial, we randomly assigned healthy adults between the ages of 18 and 55 years (cohort 1) and those 65 years of age or older (cohort 3) to receive the Ad26.COV2.S vaccine at a dose of 5×10¹⁰ viral particles (low dose) or 1×10¹¹ viral particles (high dose) per milliliter or placebo in a single-dose or two-dose schedule. Longer-term data comparing a single-dose regimen with a two-dose regimen are being collected in cohort 2; those results are not reported here. The primary end points were the safety and reactogenicity of each dose schedule.

RESULTS

After the administration of the first vaccine dose in 805 participants in cohorts 1 and 3 and after the second dose in cohort 1, the most frequent solicited adverse events were fatigue, headache, myalgia, and injection-site pain. The most frequent systemic adverse event was fever. Systemic adverse events were less common in cohort 3 than in cohort 1 and in those who received the low vaccine dose than in those who received the high dose. Reactogenicity was lower after the second dose. Neutralizing-antibody titers against wild-type virus were detected in 90% or more of all participants on day 29 after the first vaccine dose (geometric mean titer [GMT], 212 to 354), regardless of vaccine dose or age group, and reached 96% by day 57 with a further increase in titers (GMT, 288 to 488) in cohort 1a. Titers remained stable until at least day 71. A second dose provided an increase in the titer by a factor of 2.6 to 2.9 (GMT, 827 to 1266). Spike-binding antibody responses were similar to neutralizing-antibody responses. On day 15, CD4+ T-cell responses were detected in 76 to 83% of the participants in cohort 1 and in 60 to 67% of those in cohort 3, with a clear skewing toward type 1 helper T cells. CD8+ T-cell responses were robust overall but lower in cohort 3.

CONCLUSIONS

The safety and immunogenicity profiles of Ad26.COV2.S support further development of this vaccine candidate. (Funded by Johnson & Johnson and the Biomedical Advanced Research and Development Authority of the Department of Health and Human Services; COV1001 ClinicalTrials.gov number, NCT04436276.).

Immunogenicity and safety of a tri-antigenic versus a mono-antigenic hepatitis B vaccine in adults (PROTECT): a randomised, double-blind, phase 3 trial

BACKGROUND

The seroprotection rate (SPR) of hepatitis B vaccination in adults is suboptimal. The aim of this study was to compare the SPR of a tri-antigenic hepatitis B vaccine (TAV), with a mono-antigenic vaccine (MAV) in adults of all ages.

METHODS

This was a multicentre, double-blind, phase 3, randomised controlled trial (PROTECT) comparing the immunogenicity and safety of TAV with MAV in 28 community and hospital sites in the USA, Finland, Canada, and Belgium. Adults (aged ≥18 years) seronegative for hepatitis B virus (HBV), including those with well-controlled common chronic conditions, were randomly assigned (1:1) and stratified by study centre and age according to a web-based permuted blocked randomisation. Participants received either TAV or MAV which were administered as an intramuscular dose (1 mL) of TAV (10 μg; Sci-B-Vac, VBI Vaccines [SciVac, Rehovot, Israel]) or MAV (20 μg; Engerix-B [GlaxoSmithKline Biologicals, Rixensart, Belgium]) on days 0, 28, and 168 with six study visits and 24 weeks of follow-up after the third vaccination. Participants, investigators, and those assessing outcomes were masked to group assignment. The co-primary outcomes were to show non-inferiority of the SPRs 4 weeks after the third vaccination with TAV versus MAV in adults aged 18 years and older, as well as superiority in adults aged 45 years and older. SPR was defined as the percentage of participants attaining anti-HBs titres of 10 mIU/mL or higher. Non-inferiority of TAV to MAV was concluded if the lower limit of the 95% CI for the between-group difference was greater than -5%. Non-inferiority was assessed in the per-protocol set of participants (aged ≥18 years) and superiority was assessed in all participants (aged ≥45 years) who received at least one vaccination and had at least one evaluable immunogenicity sample after baseline (full analysis set). Safety analyses were a secondary outcome and included all participants who received at least one injection. This trial is registered at Clinicaltrials.gov (NCT03393754) and EudraCT (2017-001819-36) and is closed to new participants.

FINDINGS

Between Dec 13, 2017, and April 8, 2019, 1607 participants (796 allocated to TAV and 811 allocated to MAV) were randomly assigned and distributed across age cohorts of 18-44 years (299 of 1607; 18·6%), 45-64 years (716 of 1607; 44·6%), and 65 years and older (592 of 1607; 36·8%). In participants aged 18 years and older, SPR was 91·4% (656 of 718) in the TAV group versus 76·5% (553 of 723) in the MAV group (difference 14·9%, 95% CI 11·2-18·6), showing non-inferiority in the per-protocol set. In participants aged 45 years and older, SPR was 89·4% (559 of 625) in the TAV group versus 73·1% (458 of 627) in the MAV group (difference 16·4%, 95% CI 12·2-20·7), showing superiority in the full analysis set. TAV was associated with higher rates of mild or moderate injection site pain (63·2% [503 of 796] in TAV vs 36·3% [294 of 811] in MAV), tenderness (60·8% [484 of 796] in TAV vs 34·8% [282 of 811] in MAV), and myalgia (34·7% [276 of 796] vs 24·3% [197 of 811] in MAV). Otherwise, the safety profile of TAV was similar to that of MAV.

INTERPRETATION

The safety and efficacy of TAV shows its usefulness for the prevention of HBV infection in adults, including those with stable and controlled chronic conditions.

FUNDING

VBI Vaccines.

Safety and immunogenicity of a new Sabin inactivated poliovirus vaccine candidate produced on the PER.C6® cell-line: a phase 1 randomized controlled trial in adults

This first-in-human study (NCT03032588), conducted in Belgium, evaluated a new inactivated poliovirus vaccines (IPV) candidate based on Sabin poliovirus strains grown on the high-yield PER.C6® cell line. Healthy adults (N = 32) were randomized (1:1) to receive a single dose of PER.C6-based Sabin-IPV (sIPV, 15:35:112.5 DU/dose) or conventional Salk-IPV (cIPV, 40:8:32 DU/dose). Reactogenicity was assessed up to 7 days after vaccination, immunogenicity 28 days after vaccination, and safety up to 6 months after vaccination.Solicited adverse events (AEs) were mild to moderate, no changes of concern in vital signs or safety laboratory values were observed, and no severe AEs (SAEs) or vaccine-related unsolicited AEs were reported after vaccination. A trend to more frequent solicited AEs after sIPV than after cIPV administration was observed. Most participants had preexisting neutralizing antibodies against poliovirus types (titer ≥8), which were strongly boosted by sIPV. Post-vaccination geometric mean titers were high (≥12,000) and similar across the two vaccination groups. Only participants with very high preexisting antibody levels did not show a vaccine-induced response, defined in seropositive participants as a 4-fold titer increase. The 10 initially seronegative (titer <8) participants (n = 5 in each study group) seroconverted and all participants had seroprotective antibody levels post-vaccination. The antibodies elicited by sIPV neutralized both Sabin and Salk poliovirus strains.In conclusion, the PER.C6®-based sIPV was well tolerated and highly immunogenic in adults with preexisting antibodies to poliovirus.

Proof-of-concept of a low-dose unmodified mRNA-based rabies vaccine formulated with lipid nanoparticles in human volunteers: A phase 1 trial

Introduction

In a first-in-human study immune responses to rabies virus glycoprotein (RABV-G)-mRNA vaccine were dependent on the route of administration, necessitating specialized devices. Following successful preclinical studies with mRNA encapsulated in lipid nanoparticles (LNP), we tested an mRNA-LNP formulation (CV7202).

Methods

In this phase 1, multi-center, controlled study in Belgium and Germany we enrolled 55 healthy 18–40-year-olds to receive intramuscular injections of 5 μg (n = 10), 1 μg (n = 16), or 2 μg (n = 16) CV7202 on Day 1; subsets (n = 8) of 1 μg and 2 μg groups received second doses on Day 29. Controls (n = 10) received rabies vaccine, Rabipur, on Days 1, 8 and 29. Safety and reactogenicity were assessed up to 28 days post-vaccination using diary cards; immunogenicity was measured as RABV-G-specific neutralizing titers (VNT) by RFFIT and IgG by ELISA.

Results

As initially tested doses of 5 μg CV7202 elicited unacceptably high reactogenicity we subsequently tested 1 and 2 μg doses which were better tolerated. No vaccine-related serious adverse events or withdrawals occurred. Low, dose-dependent VNT responses were detectable from Day 15 and by Day 29%, 31% and 22% of 1, 2 and 5 μg groups, respectively, had VNTs ≥ 0·5 IU/mL, considered an adequate response by the WHO. After two 1 or 2 μg doses all recipients had titers ≥ 0.5 IU/mL by Day 43. Day 57 GMTs were not significantly lower than those with Rabipur, which elicited adequate responses in all vaccinees after two doses. CV7202-elicited VNT were significantly correlated with RABV-G-specific IgG antibodies (r² = 0.8319, p < 0.0001).

Conclusions

Two 1 μg or 2 μg doses of CV7202 were well tolerated and elicited rabies neutralizing antibody responses that met WHO criteria in all recipients, but 5 μg had unacceptable reactogenicity for a prophylactic vaccine.

ClinicalTrials.gov Identifier: NCT03713086.

Combined oropharyngeal/nasal swab is equivalent to nasopharyngeal sampling for SARS-CoV-2 diagnostic PCR

Background

Early 2020, a COVID-19 epidemic became a public health emergency of international concern. To address this pandemic broad testing with an easy, comfortable and reliable testing method is of utmost concern. Nasopharyngeal (NP) swab sampling is the reference method though hampered by international supply shortages. A new oropharyngeal/nasal (OP/N) sampling method was investigated using the more readily available throat swab.

Results

35 patients were diagnosed with SARS-CoV-2 by means of either NP or OP/N sampling. The paired swabs were both positive in 31 patients. The one patient who tested negative on both NP and OP/N swab on admission, was ultimately diagnosed on bronchoalveolar lavage fluid. A strong correlation was found between the viral RNA loads of the paired swabs (r = 0.76; P < 0.05). The sensitivity of NP and OP/N analysis in hospitalized patients (n = 28) was 89.3% and 92.7% respectively.

Conclusions

This study demonstrates equivalence of NP and OP/N sampling for detection of SARS-CoV-2 by means of rRT-PCR. Sensitivity of both NP and OP/N sampling is very high in hospitalized patients.

Safety and immunogenicity of two novel type 2 oral poliovirus vaccine candidates compared with a monovalent type 2 oral poliovirus vaccine in healthy adults: two clinical trials

BACKGROUND

Two novel type 2 oral poliovirus vaccine (OPV2) candidates, novel OPV2-c1 and novel OPV2-c2, designed to be more genetically stable than the licensed Sabin monovalent OPV2, have been developed to respond to ongoing polio outbreaks due to circulating vaccine-derived type 2 polioviruses.

METHODS

We did two randomised studies at two centres in Belgium. The first was a phase 4 historical control study of monovalent OPV2 in Antwerp, done before global withdrawal of OPV2, and the second was a phase 2 study in Antwerp and Ghent with novel OPV2-c1 and novel OPV2-c2. Eligible participants were healthy adults aged 18-50 years with documented history of at least three polio vaccinations, including OPV in the phase 4 study and either OPV or inactivated poliovirus vaccine (IPV) in the novel OPV2 phase 2 study, with no dose within 12 months of study start. In the historical control trial, participants were randomly assigned to either one dose or two doses of monovalent OPV2. In the novel OPV2 trial, participants with previous OPV vaccinations were randomly assigned to either one or two doses of novel OPV2-c1 or to one or two doses of novel OPV2-c2. IPV-vaccinated participants were randomly assigned to receive two doses of either novel OPV2-c1, novel OPV2-c2, or placebo. Vaccine administrators were unmasked to treatment; medical staff performing safety and reactogenicity assessments or blood draws for immunogenicity assessments were masked. Participants received the first vaccine dose on day 0, and a second dose on day 28 if assigned to receive a second dose. Primary objectives were assessments and comparisons of safety up to 28 days after each dose, including solicited adverse events and serious adverse events, and immunogenicity (seroprotection rates on day 28 after the first vaccine dose) between monovalent OPV2 and the two novel OPV2 candidates. Primary immunogenicity analyses were done in the per-protocol population. Safety was assessed in the total vaccinated population-ie, all participants who received at least one dose of their assigned vaccine. The phase 4 control study is registered with EudraCT (2015-003325-33) and the phase 2 novel OPV2 study is registered with EudraCT (2018-001684-22) and ClinicalTrials.gov (NCT04544787).

FINDINGS

In the historical control study, between Jan 25 and March 18, 2016, 100 volunteers were enrolled and randomly assigned to receive one or two doses of monovalent OPV2 (n=50 in each group). In the novel OPV2 study, between Oct 15, 2018, and Feb 27, 2019, 200 previously OPV-vaccinated volunteers were assigned to the four groups to receive one or two doses of novel OPV2-c1 or novel OPV2-c2 (n=50 per group); a further 50 participants, previously vaccinated with IPV, were assigned to novel OPV2-c1 (n=17), novel OPV2-c2 (n=16), or placebo (n=17). All participants received the first dose of assigned vaccine or placebo and were included in the total vaccinated population. All vaccines appeared safe; no definitely vaccine-related withdrawals or serious adverse events were reported. After first doses in previously OPV-vaccinated participants, 62 (62%) of 100 monovalent OPV2 recipients, 71 (71%) of 100 recipients of novel OPV2-c1, and 74 (74%) of 100 recipients of novel OPV2-c2 reported solicited systemic adverse events, four (monovalent OPV2), three (novel OPV2-c1), and two (novel OPV2-c2) of which were considered severe. In IPV-vaccinated participants, solicited adverse events occurred in 16 (94%) of 17 who received novel OPV2-c1 (including one severe) and 13 (81%) of 16 who received novel OPV2-c2 (including one severe), compared with 15 (88%) of 17 placebo recipients (including two severe). In previously OPV-vaccinated participants, 286 (97%) of 296 were seropositive at baseline; after one dose, 100% of novel OPV2 vaccinees and 97 (97%) of monovalent OPV2 vaccinees were seropositive.

INTERPRETATION

Novel OPV2 candidates were as safe, well tolerated, and immunogenic as monovalent OPV2 in previously OPV-vaccinated and IPV-vaccinated adults. These data supported the further assessment of the vaccine candidates in children and infants.

FUNDING

University of Antwerp and Bill & Melinda Gates Foundation.

119. A Respiratory Syncytial Virus Prefusion F Protein (RSVPreF3) Candidate Vaccine Administered in Older Adults in a Phase I/II Randomized Clinical Trial Is Well Tolerated

Background

RSV is a common cause of respiratory acute illness in older adults (OA). We evaluated safety and reactogenicity of RSVPreF3 candidate vaccine in young adults (YA) and OA.

Methods

In this phase I/II, placebo-controlled, multi-country trial (NCT03814590), YA aged 18–40 years were randomized 1:1:1:1 and received 2 doses of Low-, Medium- or High-dose of RSVPreF3 non-adjuvanted vaccine, or placebo, 2 months apart. Following favorable safety evaluation, a staggered enrolment with 2 steps followed in OA aged 60–80 years, who were randomized 1:1:1:1:1:1:1:1:1:1 to receive 1 of the 9 RSV vaccine formulations containing Low-, Medium- or High-dose of RSVPreF3 non-adjuvanted or adjuvanted with AS01_E or AS01_B, or placebo (same schedule). Safety/reactogenicity up to 1 month post-dose 1 are reported here.

Results

Exposed set was comprised of 48 YA and 1005 OA. Within 7 days post-dose 1, any solicited/unsolicited adverse event (AE) ranged from 58.3% to 83.3% across YA vaccinees (placebo YA: 58.3%) and from 29.9% to 84.2% across OA vaccinees (placebo OA: 33.7%) (Fig 1). Pain was the most common solicited local AE, being reported in ≤ 58.3% of YA (placebo YA: 0.0%) and at higher rates in the adjuvanted groups (≤ 75.7%) vs non-adjuvanted groups of OA (≤ 14.1%) and placebo OA (4.1%) (Fig 2A). Of solicited general AEs, fatigue (YA: ≤ 41.7% in vaccinees vs 50.0% in placebo; OA: ≤ 48.5% in vaccinees vs 16.3% in placebo) and headache (YA: ≤ 33.3% in vaccinees vs 16.7% in placebo; OA: ≤ 27.7% in vaccinees vs 8.2% in placebo) were most commonly reported (Fig 2B), while fever ≥ 38.0 °C was observed in ≤ 3.0% of OA vaccinees (placebo OA: 0.0%). Grade 3 solicited local and general AEs were observed in OA only, with erythema (≤ 4.9% in vaccinees vs 0.0% in placebo) and fatigue (≤ 2.0% in vaccinees vs 1.0% in placebo) being most common (Fig 2). No serious AEs (SAEs) were reported in YA. A number of 11 OA reported a SAE within 1 month post-dose 1, but none was fatal or assessed as vaccine-related. No clinically significant abnormalities occurred in hematological/biochemical parameters in any group.

Figure 1. Percentage of participants presenting at least one type of solicited/unsolicited adverse event (AE) within 7 days post-dose 1

Figure 2. Percentage of participants with at least one type of solicited adverse event (AE) within 7 days post-dose 1

Conclusion

First dose of RSVPreF3 candidate vaccine is well tolerated. AE rates tended to be higher after AS01_B-adjuvanted formulations compared to other vaccine formulations. No safety concerns were raised.

Funding

GlaxoSmithKline Biologicals SA

Disclosures

Jelena Tica, PhD, GSK group of companies (Employee, Shareholder) Javier Ruiz Guiñazú, MD MSc, GSK group of companies (Employee, Shareholder) Charles P. Andrews, MD, GSK group of companies (Scientific Research Study Investigator) Charles Fogarty, MD, GSK group of companies (Grant/Research Support) Edward Kerwin, MD, Amphastar (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)AstraZeneca (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Boehringer Ingelheim (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Chiesi (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Cipla (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)GSK group of companies (Employee, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Mylan (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Novartis (Employee, Advisor or Review Panel member, Research Grant or Support, Speaker’s Bureau)other around 40 pharmaceutical companies (Other Financial or Material Support, conducted multicenter clinical research trials)Pearl (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Sunovion (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Theravance (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau) Isabel Leroux-Roels, MD PhD, GSK group of companies (Scientific Research Study Investigator) Corinne Vandermeulen, MD PhD, GSK group of companies (Other Financial or Material Support, My university only received Grant/Research Support) Marie-Pierre David, MSc, GSK group of companies (Employee, Shareholder) Nancy Dezutter, PhD, PharmD, RPh, GSK group of companies (Employee, Shareholder) Laurence Fissette, MSc, GSK group of companies (Employee) Juliane Koch, MD, GSK group of companies (Employee, Shareholder) Narcisa Mesaros, MD, MSc, GSK group of companies (Employee)

121. A Respiratory Syncytial Virus Prefusion F Protein (RSVPreF3) Candidate Vaccine Administered in Older Adults in a Phase I/II Randomized Clinical Trial Is Immunogenic

Background

RSV causes significant disease burden in older adults, since reinfections are common and may lead to severe disease presentations while only supportive treatment is available. We present immunogenicity of different formulations of an investigational vaccine (RSVPreF3) in young and older adults.

Methods

This is a phase I/II, placebo-controlled, multi-country trial (NCT03814590). Healthy adults aged 18–40 years were randomized 1:1:1:1 to receive 2 doses of either Low-, Medium- or High-dose of RSVPreF3 non-adjuvanted vaccine or placebo, 2 months apart. Following favorable safety outcomes, adults aged 60–80 years were randomized 1:1:1:1:1:1:1:1:1:1 in a 2-step staggered manner to receive 1 of the 9 RSV vaccine formulations containing Low-, Medium- or High-dose of RSVPreF3, non-adjuvanted or adjuvanted with AS01_E or AS01_B, or placebo (same schedule). Humoral and cellular-mediated immune responses are assessed before and after each dose; results up to 1 month post-dose 1 are shown here.

Results

Of 48 adults aged 18–40 years and 1005 aged 60–80 years included in the exposed set, 42 and 933, respectively, were part of per-protocol set at 1 month post-dose 1. RSVPreF3 IgG geometric mean antibody concentrations were 8.4–13.5 and 7.2–12.8 fold-higher at 1 month post-dose 1 vs baseline in the 18–40- and 60–80-year-old vaccinees, respectively (Fig 1A). RSV-A neutralization activity significantly increased in all RSV vaccinees, geometric mean antibody titers being 7.5–13.7 and 5.6–9.9 fold-higher in 18–40- and 60–80-year-olds, respectively, at 1 month post-dose 1 vs baseline (Fig 1B). Geometric mean ratios of the fold increase between RSVPreF3 IgG antibody concentrations and RSV-A neutralizing antibody titers ranged between 0.9–1.1 in 18–40-year-old and 1.3–1.5 in 60–80-year-old vaccinees. A robust RSVPreF3-specific CD4+ T-cell response was elicited at 1 month post-dose 1 vs baseline in both 18–40- and 60–80-year-olds (Fig 2).

Figure 1. RSVPreF3 IgG geometric mean antibody concentrations (GMCs, enzyme-linked immunosorbent assay, panel A), RSV-A neutralizing geometric mean antibody titers (GMTs, neutralization assay, panel B)

Figure 2. RSVPreF3-specific CD4+ T-cells identified as expressing ≥2 markers among IL2, CD40L, TNF-□, IFN-□ (intracellular cytokine staining assay)

Conclusion

One dose of RSVPreF3 candidate vaccine boosted humoral and cellular immune responses in all vaccinees. In older adults, higher humoral response, mostly neutralizing, was observed with increased RSVPreF3 antigen dosage and a tendency of higher cellular response was observed after adjuvanted formulations.

Funding

GlaxoSmithKline Biologicals SA

Disclosures

Javier Ruiz Guiñazú, MD MSc, GSK group of companies (Employee, Shareholder) Jelena Tica, PhD, GSK group of companies (Employee, Shareholder) Charles P. Andrews, MD, GSK group of companies (Scientific Research Study Investigator) Charles Fogarty, MD, GSK group of companies (Grant/Research Support) Edward Kerwin, MD, Amphastar (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)AstraZeneca (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Boehringer Ingelheim (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Chiesi (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Cipla (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)GSK group of companies (Employee, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Mylan (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Novartis (Employee, Advisor or Review Panel member, Research Grant or Support, Speaker’s Bureau)other around 40 pharmaceutical companies (Other Financial or Material Support, conducted multicenter clinical research trials)Pearl (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Sunovion (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau)Theravance (Consultant, Scientific Research Study Investigator, Advisor or Review Panel member, Speaker’s Bureau) Isabel Leroux-Roels, MD PhD, GSK group of companies (Scientific Research Study Investigator) Corinne Vandermeulen, MD PhD, GSK group of companies (Other Financial or Material Support, My university only received Grant/Research Support) Marie-Pierre David, MSc, GSK group of companies (Employee, Shareholder) Nancy Dezutter, PhD, PharmD, RPh, GSK group of companies (Employee, Shareholder) Nathalie De Schrevel, PhD, GSK group of companies (Employee) Laurence Fissette, MSc, GSK group of companies (Employee) Narcisa Mesaros, MD, MSc, GSK group of companies (Employee)

Infection prevention and control challenges in Flemish homecare nursing: a pilot study

Home nursing is evolving towards more invasive care. Nevertheless, no national data are available on the prevalence of HAI in this setting. The aim of this pilot study is to explore the Flemish home care setting as a first step toward a national surveillance program. A survey, focused on patient characteristics and HAI, was conducted between 7 May and 20 July 2018 on 711 Flemish patients. Most of the patients (74%) are 65 years or older and half of them had a form of comorbidity. Assisting with personal hygiene and wound care were the most frequent services delivered by home care nurses. A comparison of the prevalence of infections diagnosed by a physician or applying uniform criteria (ECDC), revealed a similar prevalence of skin and soft tissue infections (9% vs. 8.5%) and urinary tract infections (4% vs. 4.5%). A positive MDRO-screening was found in 6% of the patients. This pilot study is a first step towards a standardized national surveillance in home care to collect information on the prevalence of HAI and it reveals several interesting facts and study pitfalls for this setting.

Toilet drain water as a potential source of hospital room-to-room transmission of carbapenemase-producing Klebsiella pneumoniae

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) have rapidly emerged in Europe, being responsible for nosocomial outbreaks.

AIM

Following an outbreak in the burn unit of Ghent University Hospital, we investigated whether CPE can spread between toilets through drain water and therefrom be transmitted to patients.

METHODS

In 2017, the burn centre of our hospital experienced an outbreak of OXA-48-producing Klebsiella pneumoniae that affected five patients staying in three different rooms. Environmental samples were collected from the sink, shower, shower stretcher, hand rail of the bed, nursing carts, toilets, and drain water to explore a common source. Whole-genome sequencing and phylogenetic analysis was performed on K. pneumoniae outbreak isolates and two random K. pneumoniae isolates.

FINDINGS

OXA-48-producing K. pneumoniae was detected in toilet water in four out of six rooms and drain water between two rooms. The strain persisted in two out of six rooms after two months of daily disinfection with bleach. All outbreak isolates belonged to sequence type (ST) 15 and showed isogenicity (<15 allele differences). This suggests that the strain may have spread between rooms by drain water. Unexpectedly, one random isolate obtained from a patient who became colonized while residing at the geriatric ward clustered with the outbreak isolates, suggesting the outbreak to be larger than expected. Daily application of bleach tended to be superior to acetic acid to disinfect toilet water; however, disinfection did not completely prevent the presence of carbapenemase-producing K. pneumoniae in toilet water.

CONCLUSION

Toilet drain water may be a potential source of hospital room-to-room transmission of carbapenemase-producing K. pneumoniae.

ATP measurement as an objective method to measure environmental contamination in 9 hospitals in the Dutch/Belgian border area

Background

The objective of this study was to determine the level of environmental contamination in hospitals in the Dutch/Belgian border area, using ATP measurements.

Design

A cross-sectional observational survey.

Methods

Standardized ATP measurements were conducted in 9 hospitals on 32 hospital wards. Thirty pre-defined surfaces per hospital ward were measured with the 3 M Clean Trace NG luminometer. Results are displayed in relative light units (RLU). RLU > 1000 was considered as “not clean.” Differences in RLU values were compared between countries, hospitals, fomite groups and medical specialties.

Results

A total of 960 ATP measurements were performed, ranging from 60 up to 120 per hospital. The median RLU-value was 568 (range: 3–277,586) and 37.7% of the measurements were rated as not clean (RLU > 1000). There were significant differences between countries, hospitals and fomite groups.

Conclusion

ATP measurements can be used as a more objective approach to determine the level of environmental contamination in hospitals. Significant differences in ATP levels were found between hospitals and between countries. Also, substantial differences were found between different fomite groups. These findings offer potential targets for improvement of cleanliness in healthcare facilities.

Persistence of vaccine-elicited immune response up to 14 years post-HIV gp120-NefTat/AS01B vaccination

BACKGROUND

Vaccines eliciting protective and persistent immune responses against multiple human immunodeficiency virus type 1 (HIV-1) clades are needed. This study evaluated the persistence of immune responses induced by an investigational, AS01-adjuvanted HIV-1 vaccine as long as 14 years after vaccination.

METHODS

This phase I, open-label, descriptive, mono-centric, extension study with a single group (NCT03368053) was conducted in adults who received ≥3 doses of the clade B gp120-NefTat/AS01_B vaccine candidate 14 years earlier in a previous clinical trial (NCT00434512). Binding responses of serum antibodies targeting a panel of envelope glycoproteins, including gp120, gp140 and V1V2-scaffold antigens and representative of the antigenic diversity of HIV-1, were measured by binding antibody multiplex assay (BAMA). The gp120-specific CD4+/CD8+ T-cell responses were assessed by intracellular cytokine staining assay.

RESULTS

At Year 14, positive IgG binding antibody responses were detected in 15 out of the 16 antigens from the BAMA V1V2 breadth panel, with positive response rates ranging from 7.1% to 60.7%. The highest response rates were observed for clade B strain V1V2 antigens, with some level of binding antibodies against clade C strains. Anti-V1V2 IgG3 response magnitude breadth, which correlated with decreased risk of infection in a previous efficacy trial, was of limited amplitude. Response rates to the antigens from the gp120 and gp140 breadth panels ranged from 7.7% to 94.1% and from 15.4% to 96.2% at Year 14, respectively. Following stimulation with gp120 peptide pool, highly polyfunctional gp120-specific CD4+ T-cells persisted up to Year 14, with high frequencies of CD40L tumor necrosis factor alpha (TNF-α), CD40L interleukin-2 (IL-2), CD40L TNF-α IL-2 and CD40L interferon gamma (IFN-γ) TNF-α IL-2 CD4+ T-cells, but no CD8+ T-cells detected.

CONCLUSIONS

Persistent antibodies binding to HIV-1 envelope glycoproteins, including the V1V2-scaffold, and gp120-specific cellular immunity were observed in volunteers vaccinated 14 years earlier with the gp120-NefTat/AS01_B vaccine candidate.

LB13. Trivalent Hepatitis B (HepB) Vaccine Yields Superior Seroprotection Rates in Adults: Results from the Phase 3 Double-Blind, Randomized Study Comparing Immunogenicity and Safety of a 3-Dose Regimen of Sci-B-Vac™ and Engerix B® (PROTECT)

Background

Many adults fail to achieve seroprotection after receiving 3 doses of monovalent HepB vaccines such as Engerix-B® and the response decreases with age and with common co-morbidities. Sci-B-Vac™ is a trivalent HepB vaccine produced in mammalian cells, adjuvanted with aluminum hydroxide, which in addition to small S antigen, contains preS1 and preS2 antigens expressing highly immunogenic T- and B-cell epitopes that may enhance seroprotection rates (SPR) in adults.

Methods

In a multicentre study, the immunogenicity of 10 µg dose of Sci-B-Vac™ was compared with a 20-µg dose of Engerix-B® given at days 0, 28, and 168 (NCT03393754). Randomization was stratified by study center and age (18–44, 45–64, ≥65 years). Immunogenicity, including SPR (% subjects with anti-HBs levels ≥10 mIU/mL), and safety outcomes were followed to Day 336. The co-primary objectives were (1) non-inferiority in adults ≥18 years and (2) superiority in adults ≥45 years of SPR, 4 weeks after the third dose.

Results

Of 1,607 randomized subjects, 42.3% were from United States, 41.6% EU, and 16.1% Canada. Males (38.5%) and females (61.5%) were enrolled to 18–44 (18.6%), 45–64 (44.6%), and ≥ 65 year (36.8%) age groups. Both co-primary endpoints were met. In the non-inferiority analysis, SPR in Sci-B-Vac™ recipients aged ≥18 years was 91.4% vs. 76.5% for Engerix-B®; SPR difference: 14.9%; 95% confidence interval (CI) [11.2%, 18.6%]. Superiority analysis showed that SPR in Sci-B-Vac™ recipients aged ≥45 years was 89.4% vs. 73.1% for Engerix-B®—SPR difference: 16.4%; 95% CI [12.2%, 20.7%] (figure). Significantly higher SPR for Sci-B-Vac™ vs. Engerix-B® was noted in subgroups (gender, BMI, diabetes, smoking and particularly age—SPR difference for 45–64 (14.7% [9.8–19.8%]) and ≥ 65 (18.9% [11.6–26.1%]) years. No major safety signals were observed; solicited and unsolicited adverse events were consistent with the known vaccine safety profiles.

Conclusion

Sci-B-Vac™ met immunogenicity endpoints for non-inferiority in adults aged ≥ 8 years and was superior in adults aged ≥45 years, compared with the monovalent vaccine, Engerix-B®. Sci-B-Vac™ SPR was higher compared with Engerix-B® in key subgroups. No safety signals were observed and safety and tolerability were consistent with the known profile of Sci-B-Vac™.

Disclosures

Timo Vesikari, MD, VBI (Grant/Research Support, I have received funding from VBI to carry out the reported clinical trial in Finland), Joanne M. Langley, MD, VBI Vaccines (Grant/Research Support), Johanna Spaans, BSc, MSc, VBI Vaccines (Employee), Nathalie Machluf, PhD, SciVac Ltd. (Employee), Dave Anderson, PhD, VBI Vaccines, Inc. (Employee, Shareholder), Vlad Popovic, MD, VBI Vaccines (Employee), Francisco Diaz-Mitoma, MD, VBI Vaccines, Inc. (Consultant, Shareholder, Independent Contractor). Other Authors: No reported disclosures.

A recurrent and transesophageal echocardiography-associated outbreak of extended-spectrum β-lactamase-producing Enterobacter cloacae complex in cardiac surgery patients

Background

We report a recurrent outbreak of postoperative infections with extended-spectrum β-lactamase (ESBL)–producing E. cloacae complex in cardiac surgery patients, describe the outbreak investigation and highlight the infection control measures.

Methods

Cases were defined as cardiac surgery patients in Ghent University Hospital who were not known preoperatively to carry ESBL-producing E. cloacae complex and who postoperatively had a positive culture for this multiresistant organism between May 2017 and January 2018. An epidemiological investigation, including a case-control study, and environmental investigation were conducted to identify the source of the outbreak. Clonal relatedness of ESBL-producing E. cloacae complex isolates collected from case patients was assessed using whole-genome sequencing–based studies.

Results

Three separate outbreak episodes occurred over the course of 9 months. A total of 8, 4 and 6 patients met the case definition, respectively. All but one patients developed a clinical infection with ESBL-producing E. cloacae complex, most typically postoperative pneumonia. Overall mortality was 22% (4/18). Environmental cultures were negative, but epidemiological investigation pointed to transesophageal echocardiography (TEE) as the outbreak source. Of note, four TEE probes showed a similar pattern of damage, which very likely impeded adequate disinfection. The first and second outbreak episode were caused by the same clone, whereas a different strain was responsible for the third episode.

Conclusions

Health professionals caring for cardiac surgery patients and infection control specialists should be aware of TEE as possible infection source. Caution must be exercised to prevent and detect damage of TEE probes.

Nosocomial outbreak of extended-spectrum β-lactamase-producing Enterobacter cloacae among cardiothoracic surgical patients: causes and consequences

BACKGROUND

Enterobacteriaceae are recognized as leading pathogens of healthcare-associated infections.

AIM

To report the investigation of a nosocomial outbreak of extended-spectrum β-lactamase-producing Enterobacter cloacae affecting cardiothoracic surgery patients in a Belgian academic hospital.

METHODS

Cases were defined based on epidemiological and microbiological investigations, including molecular typing using repetitive element-based polymerase chain reaction and multi-locus sequence typing. Case-control studies followed by field evaluations allowed the identification of a possible reservoir, and the retrospective assessment of human and financial consequences.

FINDINGS

Over a three-month period, 42 patients were infected or colonized by CTX-M-15-producing E. cloacae strains that belonged to the same clonal lineage. Acquisition mainly occurred in the intensive care unit (N = 23) and in the cardiothoracic surgery ward (N = 16). All but one patient had, prior to acquisition, undergone a cardiothoracic surgical procedure, monitored by the same transoesophageal echocardiography (TOE) probe in the operating room. Despite negative microbiological culture results, the exclusion of the suspected probe resulted in rapid termination of the outbreak. Overall, the outbreak was associated with a high mortality rate among infected patients (40%) as well as significant costs (€266,550).

CONCLUSION

The outbreak was indirectly shown to be associated with the contamination of a manually disinfected TOE probe used per-operatively during cardiothoracic surgery procedures, because withdrawal of the putative device led to rapid termination of the outbreak.

Evaluation of the immune response to RTS,S/AS01 and RTS,S/AS02 adjuvanted vaccines: randomized, double-blind study in malaria-naïve adults

This phase II, randomized, double-blind study evaluated the immunogenicity of RTS,S vaccines containing Adjuvant System AS01 or AS02 as compared with non-adjuvanted RTS,S in healthy, malaria-naïve adults (NCT00443131). Thirty-six subjects were randomized (1:1:1) to receive RTS,S/AS01, RTS,S/AS02, or RTS,S/saline at months 0, 1, and 2. Antibody responses to Plasmodium falciparum circumsporozoite (CS) and hepatitis B surface (HBs) antigens were assessed and cell-mediated immune responses evaluated by flow cytometry using intracellular cytokine staining on peripheral blood mononuclear cells. Anti-CS antibody avidity was also characterized. Safety and reactogenicity after each vaccine dose were monitored. One month after the third vaccine dose, RTS,S/AS01 (160.3 EU/mL [95%CI: 114.1-225.4]) and RTS,S/AS02 (77.4 EU/mL (95%CI: 47.3-126.7)) recipients had significantly higher anti-CS antibody geometric mean titers (GMTs) than recipients of RTS,S/saline (12.2 EU/mL (95%CI: 4.8-30.7); P < 0.0001 and P = 0.0011, respectively). The anti-CS antibody GMT was significantly higher with RTS,S/AS01 than with RTS,S/AS02 (P = 0.0135). Anti-CS antibody avidity was in the same range in all groups. CS- and HBs-specific CD4(+) T cell responses were greater for both RTS,S/AS groups than for the RTS,S/saline group. Reactogenicity was in general higher for RTS,S/AS compared with RTS,S/saline. Most grade 3 solicited adverse events (AEs) were of short duration and grade 3 solicited general AEs were infrequent in the 3 groups. No serious adverse events were reported. In conclusion, in comparison with non-adjuvanted RTS,S, both RTS,S/AS vaccines exhibited better CS-specific immune responses. The anti-CS antibody response was significantly higher with RTS,S/AS01 than with RTS,S/AS02. The adjuvanted vaccines had acceptable safety profiles.

Implementation of a multidisciplinary infectious diseases team in a tertiary hospital within an Antimicrobial Stewardship Program

BACKGROUND

In January 2011, as part of an antimicrobial stewardship program the Antimicrobial Management Team (AMT) at the Ghent University Hospital initiated a multidisciplinary Infectious Diseases Team (MIT) consisting of infectious diseases physicians, clinical microbiologists, and clinical pharmacists. The aim of this study is to describe the type and acceptance rate of recommendations provided by the MIT.

METHOD

Prospective, observational study in a tertiary care, university teaching hospital with 1062 beds in non-consecutive hospitalized adult patients, excluding intensive care units and paediatrics.

RESULTS

The MIT communicated 432 recommendations in 87 days observed. Of the 293 patients for whom a recommendation was made, the median age was 57 years (range: 16-91 years) and 169 (57·7%) were male. Skin or soft tissue infections (14%), respiratory tract infections (13%), infections without known focus (11%), abdominal infections (11%), and bone infections (8%) were most common. Recommendations were made to perform additional clinical investigation(s) [N = 137 (27%)], to adjust the dose of an antimicrobial drug [N = 42 (8%)], to stop an antimicrobial drug [N = 104 (21%)], to switch from a parenteral to an oral drug [N = 39 (8%)] or to initiate an antimicrobial drug [N = 178 (36%)], with an acceptance rate of 73·0%, 83·3%, 81·7%, 76·9%, and 84·0%, respectively.

CONCLUSIONS

The MIT formulated about five recommendations a day primarily focusing on pharmacotherapy, but also on clinical investigations. In both fields, a high acceptance rate was observed.

Validity analysis of a unique infection surveillance system in the intensive care unit by analysis of a data warehouse built through a workflow-integrated software application

BACKGROUND

An electronic decision support programme was developed within the intensive care unit (ICU) that provides an overview of all infection-related patient data, and allows ICU physicians to add clinical information during patient rounds, resulting in prospective compilation of a database.

AIM

To assess the validity of computer-assisted surveillance (CAS) of ICU-acquired infection performed by analysis of this database.

METHODS

CAS was compared with prospective paper-based surveillance (PBS) for ICU-acquired respiratory tract infection (RTI), bloodstream infection (BSI) and urinary tract infection (UTI) over four months at a 36-bed medical and surgical ICU. An independent panel reviewed the data in the case of discrepancy between CAS and PBS.

FINDINGS

PBS identified 89 ICU-acquired infections (13 BSI, 18 UTI, 58 RTI) and CAS identified 90 ICU-acquired infections (14 BSI, 17 UTI, 59 RTI) in 876 ICU admissions. There was agreement between CAS and PBS on 13 BSI (100 %), 14 UTI (77.8 %) and 42 RTI (72.4 %). Overall, there was agreement on 69 infections (77.5%), resulting in a kappa score of 0.74. Discrepancy between PBS and CAS was the result of capture error in 11 and 14 infections, respectively. Interobserver disagreement on probability (13 RTI) and focus (two RTI, one UTI) occurred for 16 episodes. The time required to collect information using CAS is less than 30% of the time required when using PBS.

CONCLUSION

CAS for ICU-acquired infection by analysis of a database built through daily workflow is a feasible surveillance method and has good agreement with PBS. Discrepancy between CAS and PBS is largely due to interobserver variability.