Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine and an MF59-adjuvanted influenza vaccine after concomitant vaccination in ⩾60-year-old adults

Concomitant administration of seasonal influenza and COVID-19 mRNA vaccines

Current clinical guidelines support the concomitant administration of seasonal influenza vaccines and COVID-19 mRNA boosters vaccine. Whether dual vaccination may impact vaccine immunogenicity due to an interference between influenza or SARS-CoV-2 antigens is unknown. We aimed to understand the impact of mRNA COVID-19 vaccines administered concomitantly on the immune response to influenza vaccines. For this, 128 volunteers were vaccinated during the 22-23 influenza season. Three groups of vaccination were assembled: FLU vaccine only (46, 35%) versus volunteers that received the mRNA bivalent COVID-19 vaccines concomitantly to seasonal influenza vaccines, FluCOVID vaccine in the same arm (42, 33%) or different arm (40, 31%), respectively. Sera and whole blood were obtained the day of vaccination, +7, and +28 days after for antibody and T cells response quantification. As expected, side effects were increased in individuals who received the FluCOVID vaccine as compared to FLU vaccine only based on the known reactogenicity of mRNA vaccines. In general, antibody levels were high at 4 weeks post-vaccination and differences were found only for the H3N2 virus when administered in different arms compared to the other groups at day 28 post-vaccination. Additionally, our data showed that subjects that received the FluCOVID vaccine in different arm tended to have better antibody induction than those receiving FLU vaccines for H3N2 virus in the absence of pre-existing immunity. Furthermore, no notable differences in the influenza-specific cellular immune response were found for any of the vaccination groups. Our data supports the concomitant administration of seasonal influenza and mRNA COVID-19 vaccines.

Adult indication 13-valent pneumococcal conjugate vaccine clinical development overview: formulation, safety, immunogenicity (dosing and sequence), coadministration, and efficacy

INTRODUCTION

There was no 13-valent pneumococcal conjugate vaccine (PCV13) adult antibody concentration threshold regulatory criterion for licensure - unlike the pediatric indication; consequently, for the adult indication, PCV13 serotype-specific opsonophagocytic activity (OPA) geometric mean titer (GMT) values were immunobridged to the 23-valent plain polysaccharide vaccine (PPV23) to infer efficacy against invasive pneumococcal disease (IPD). Subsequently, a double-blind, randomized, controlled PCV13 efficacy trial (CAPiTA) was performed in community-living, older adults to confirm efficacy against vaccine-serotype IPD (VT-IPD) and establish efficacy against vaccine-serotype pneumococcal community-acquired pneumonia (VT-CAP).

AREAS COVERED

This article summarizes 31 publications from the PCV13 adult indication clinical development trials and other PCV13 clinical studies, organized by formulation, reactogenicity and safety, immunogenicity, coadministration, and clinical efficacy.

EXPERT OPINION

PCV13 had a favorable safety profile with an OPA response generally greater than PPV23 irrespective of age and of previous pneumococcal vaccination. PCV13 primed for enhanced immune responses with subsequent PCV13 or PPV23 dosing. Conversely, PPV23 was shown to blunt the response to subsequent PCV13. CAPiTA demonstrated PCV13 efficacy for at least five years against both VT-IPD and VT-CAP. The PCV13 clinical development program provided fundamental insights into this vaccine's adult-specific immune responses and confirmed the advantages of conjugate over plain polysaccharide technology.

Evaluation of the efficacy, safety and influencing factors of concomitant and sequential administration of viral respiratory infectious disease vaccines: a systematic review and meta-analysis

Background

There is no clear conclusion on the immunogenicity and adverse events of concomitant administration the viral respiratory infectious disease vaccines. We aimed to evaluate the impact of concomitant administering viral respiratory infectious disease vaccines on efficiencies, safety and influencing factors.

Methods

This meta-analysis included studies from PubMed, Embase, Cochrane Central Register of Clinical Trials, Web of Science, WHO COVID-19 Research, and ClinicalTrials.gov databases. Randomized controlled trials of the adult participants concomitant administered with viral respiratory infectious disease vaccine and other vaccines were included. The main outcomes were the seroconversion rate and seroprotection rate of each vaccine. Used the Mantel-Haenszel fixed effects method as the main analysis to estimate the pooled RRs and the corresponding 95% confidence intervals. The risk of bias for each trial was assessed using the Cochrane Handbook for Systematic Reviews of Interventions, while evidence certainty was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system.

Results

A total of 21 studies comprising 14060 participants with two types of vaccines were retained for the meta-analysis. Concomitant immunization reduced the geometric mean titer (RR: 0.858, 95% CI: (0.785 to 0.939)) and the geometric mean fold rise (0.754 (0.629 to 0.902)) in the SARS-COV-2 vaccine group but increased the seroconversion rate (1.033 (1.0002 to 1.067)) in the seasonal influenza vaccine group. Concomitant administration were influenced by the type of vaccine, adjuvant content, booster immunization, and age and gender of the recipient.

Conclusion

This meta-analysis suggested that the short-term protection and safety of concomitant administered were effective. Appropriate adjuvants, health promotion and counselling and booster vaccines could improve the efficiency and safety of Concomitant vaccination.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022343709.

Exploring missed opportunities for influenza vaccination and influenza vaccine co-administration patterns among Italian older adults: a retrospective cohort study

BACKGROUND

Missed opportunities constitute a main driver of suboptimal seasonal influenza vaccination (SIV) coverage in older adults. Vaccine co-administration is a way to reduce these missed opportunities. In this study, we quantified missed opportunities for SIV, identified some of their socio-structural correlates and documented SIV co-administration patterns.

METHODS

In this registry-based retrospective cohort study, we verified the SIV status of all subjects aged ≥65 years who received at least one dose of coronavirus disease 2019 (COVID-19), pneumococcal or herpes zoster vaccines during the 2022/23 influenza season. The frequency of concomitant same-day administration of SIV with other target vaccines was also assessed.

RESULTS

Among 41 112, 5482 and 3432 older adults who received ≥1 dose of COVID-19, pneumococcal and herpes zoster vaccines, missed opportunities for SIV accounted for 23.3%, 5.0% and 13.2%, respectively. Younger, male and foreign-born individuals were generally more prone to missing SIV. The co-administration of SIV with other recommended vaccines was relatively low, being 11.0%, 53.1% and 17.1% in COVID-19, pneumococcal and herpes zoster cohorts, respectively.

CONCLUSIONS

A sizeable proportion of older adults who received other recommended vaccines during the last influenza season did not receive SIV. This share of missed opportunities, which are subject to some social inequalities, may be addressed by increasing vaccine co-administration rates and implementing tailored health promotion interventions.

Evolution of Vaccines Formulation to Tackle the Challenge of Anti-Microbial Resistant Pathogens

The increasing diffusion of antimicrobial resistance (AMR) across more and more bacterial species emphasizes the urgency of identifying innovative treatment strategies to counter its diffusion. Pathogen infection prevention is among the most effective strategies to prevent the spread of both disease and AMR. Since their discovery, vaccines have been the strongest prophylactic weapon against infectious diseases, with a multitude of different antigen types and formulative strategies developed over more than a century to protect populations from different pathogens. In this review, we review the main characteristics of vaccine formulations in use and under development against AMR pathogens, focusing on the importance of administering multiple antigens where possible, and the challenges associated with their development and production. The most relevant antigen classes and adjuvant systems are described, highlighting their mechanisms of action and presenting examples of their use in clinical trials against AMR. We also present an overview of the analytical and formulative strategies for multivalent vaccines, in which we discuss the complexities associated with mixing multiple components in a single formulation. This review emphasizes the importance of combining existing knowledge with advanced technologies within a Quality by Design development framework to efficiently develop vaccines against AMR pathogens.

Safety, tolerability, and immunogenicity of V114, a 15-valent pneumococcal conjugate vaccine, administered concomitantly with influenza vaccine in healthy adults aged ≥50 years: a randomized phase 3 trial (PNEU-FLU)

Streptococcus pneumoniae and influenza viruses are associated with significant morbidity and mortality in older adults. Concomitant vaccination against these agents reduces hospitalization and mortality rates. This phase 3 trial evaluated safety, tolerability, and immunogenicity of concomitant and non-concomitant administration of V114, a 15-valent pneumococcal conjugate vaccine containing serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19F, 19A, 22F, 23F, 33F, and quadrivalent inactivated influenza vaccine (QIV), in healthy adults aged ≥50 years. Participants (N = 1,200) were randomized 1:1 to receive either V114 administered concomitantly with QIV (concomitant group) or QIV plus placebo (non-concomitant group) on Day 1, followed by placebo (concomitant group) or V114 (non-concomitant group) 30 days later. Randomization was stratified by age and history of pneumococcal polysaccharide vaccine receipt. Overall, 426 (71.0%) and 438 (73.5%) participants in the concomitant and non-concomitant groups experienced solicited injection-site adverse events (AEs); 278 (46.3%) and 300 (50.3%) reported solicited systemic AEs. Most solicited AEs were mild or moderate in severity and of short duration. Non-inferiority for pneumococcal- and influenza-specific antibody responses (lower bound 95% confidence interval of opsonophagocytic activity [OPA] and hemagglutination inhibition geometric mean titers [GMTs] ratios ≥0.5) was demonstrated for concomitant versus non-concomitant administration for all 15 pneumococcal serotypes and all four influenza strains. Consistent with previous studies, a trend was observed toward lower pneumococcal OPA GMTs in the concomitant versus the non-concomitant group. V114 administered concomitantly with QIV is generally well tolerated and immunologically non-inferior to non-concomitant administration, supporting coadministration of both vaccines.

The safety of co-administration of Bacille Calmette-Guérin (BCG) and influenza vaccines

BACKGROUND

With the emergence of novel vaccines and new applications for older vaccines, co-administration is increasingly likely. The immunomodulatory effects of BCG could theoretically alter the reactogenicity of co-administered vaccines. Using active surveillance in a randomised controlled trial, we aimed to determine whether co-administration of BCG vaccination changes the safety profile of influenza vaccination.

METHODS

Participants who received influenza vaccine alone (Influenza group) were compared with those who also received BCG-Denmark vaccine in the contralateral arm (Influenza+BCG group). Data on the influenza vaccination site were collected using serial questionnaires and active follow-up for 3 months post vaccination.

RESULTS

Of 1351 participants in the Influenza+BCG group and 1418 participants in the Influenza group, 2615 (94%) provided influenza vaccine safety data. There was no significant difference in the proportion of participants with any local adverse reaction between the Influenza+BCG group and the Influenza group (918/1293 [71.0%] versus (906/1322 [68.5%], p = 0.17). The proportion of participants reporting any pain, erythema and tenderness at the influenza vaccination site were similar in both groups. Swelling was less frequent (81/1293 [6.3%] versus 119/1322 (9.0%), p = 0.01) and the maximal diameter of erythema was smaller (mean 1.8 cm [SD 2.0] versus 3.0 cm [SD 2.5], p<0.001) in the Influenza+BCG group. Sixteen participants reported serious adverse events: 9 participants in the Influenza+BCG group and 7 in the Influenza group.

CONCLUSIONS

Adverse events following influenza vaccination are not increased when BCG is co-administered.

Safety, immunogenicity, and efficacy of a COVID-19 vaccine (NVX-CoV2373) co-administered with seasonal influenza vaccines: an exploratory substudy of a randomised, observer-blinded, placebo-controlled, phase 3 trial

BACKGROUND

The safety and immunogenicity profile of COVID-19 vaccines when administered concomitantly with seasonal influenza vaccines have not yet been reported. We therefore aimed to report the results of a substudy within a phase 3 UK trial, by evaluating the safety, immunogenicity, and efficacy of NVX-CoV2373 when co-administered with licensed seasonal influenza vaccines.

METHODS

We did a planned exploratory substudy as part of the randomised, observer-blinded, placebo-controlled, phase 3 trial of the safety and efficacy of the COVID-19 vaccine (NVX-CoV2373) by co-administrating the influenza vaccine at four study hospitals in the UK. Approximately, the first 400 participants meeting the main study entry criteria-with no contraindications to influenza vaccination-were invited to join the substudy. Participants of the main study were randomly assigned (1:1) to receive two intramuscular injections of either NVX-CoV2373 (5 μg) or placebo (normal saline) 21 days apart; participants enrolled into the substudy were co-vaccinated with a single (0·5 mL) intramuscular, age-appropriate (quadrivalent influenza cell-based vaccine [Flucelvax Quadrivalent; Seqirus UK, Maidenhead] for those aged 18-64 years and adjuvanted trivalent influenza vaccine [Fluad; Seqirus UK, Maidenhead] for those ≥65 years), licensed, influenza vaccine on the opposite deltoid to that of the first study vaccine dose or placebo. The influenza vaccine was administered in an open-label manner and at the same time as the first study injection. Reactogenicity was evaluated via an electronic diary for 7 days after vaccination in addition to monitoring for unsolicited adverse events, medically attended adverse events, and serious adverse events. Immunogenicity was assessed with influenza haemagglutination inhibition and SARS-CoV-2 anti-spike protein IgG assays. Vaccine efficacy against PCR-confirmed, symptomatic COVID-19 was assessed in participants who were seronegative at baseline, received both doses of study vaccine or placebo, had no major protocol deviations affecting the primary endpoint, and had no confirmed cases of symptomatic COVID-19 from the first dose until 6 days after the second dose (per-protocol efficacy population). Immunogenicity was assessed in participants who received scheduled two doses of study vaccine, had a baseline sample and at least one post-vaccination sample, and had no major protocol violations before unmasking (per-protocol immunogenicity population). Reactogenicity was analysed in all participants who received at least one dose of NVX-CoV2373 or placebo and had data collected for reactogenicity events. Safety was analysed in all participants who received at least one dose of NVX-CoV2373 or placebo. Comparisons were made between participants of the substudy and the main study (who were not co-vaccinated for influenza). This study is registered with ClinicalTrials.gov, number NCT04583995.

FINDINGS

Between Sept 28, 2020, and Nov 28, 2020, a total of 15 187 participants were randomised into the main phase 3 trial, of whom 15 139 received treatment (7569 received dose one of NVX-CoV2373 and 7570 received dose one of placebo). 431 participants were co-vaccinated with a seasonal influenza vaccine in the substudy (217 received NVX-CoV2373 plus the influenza vaccine and 214 received placebo plus the influenza vaccine). In general, the substudy participants were younger, more racially diverse, and had fewer comorbid conditions than those in the main study. Reactogenicity events were more common in the co-administration group than in the NVX-CoV2373 alone group: tenderness (113 [64·9%] of 174 vs 592 [53·3%] of 1111) or pain (69 [39·7%] vs 325 [29·3%]) at injection site, fatigue (48 [27·7%] vs 215 [19·4%]), and muscle pain (49 [28·3%] vs 237 [21·4%]). Incidences of unsolicited adverse events, treatment-related medically attended adverse events, and serious adverse events were low and balanced between the co-administration group and the NVX-CoV2373 alone group. No episodes of anaphylaxis or deaths were reported within the substudy. Co-administration resulted in no change to influenza vaccine immune response although a reduction in antibody responses to the NVX-CoV2373 vaccine was noted. NVX-CoV2373 vaccine efficacy in the substudy (ie, participants aged 18 to <65 years) was 87·5% (95% CI -0·2 to 98·4) and in the main study was 89·8% (95% CI 79·7-95·5).

INTERPRETATION

To our knowledge, this substudy is the first to show the safety, immunogenicity, and efficacy profile of a COVID-19 vaccine when co-administered with seasonal influenza vaccines. Our results suggest concomitant vaccination might be a viable immunisation strategy.

FUNDING

Novavax.

Safety and immunogenicity of concomitant administration of COVID-19 vaccines (ChAdOx1 or BNT162b2) with seasonal influenza vaccines in adults in the UK (ComFluCOV): a multicentre, randomised, controlled, phase 4 trial

BACKGROUND

Concomitant administration of COVID-19 and influenza vaccines could reduce burden on health-care systems. We aimed to assess the safety of concomitant administration of ChAdOx1 or BNT162b2 plus an age-appropriate influenza vaccine.

METHODS

In this multicentre, randomised, controlled, phase 4 trial, adults in receipt of a single dose of ChAdOx1 or BNT162b2 were enrolled at 12 UK sites and randomly assigned (1:1) to receive concomitant administration of either an age-appropriate influenza vaccine or placebo alongside their second dose of COVID-19 vaccine. 3 weeks later the group who received placebo received the influenza vaccine, and vice versa. Participants were followed up for 6 weeks. The influenza vaccines were three seasonal, inactivated vaccines (trivalent, MF59C adjuvanted or a cellular or recombinant quadrivalent vaccine). Participants and investigators were masked to the allocation. The primary endpoint was one or more participant-reported solicited systemic reactions in the 7 days after first trial vaccination(s), with a difference of less than 25% considered non-inferior. Analyses were done on an intention-to-treat basis. Local and unsolicited systemic reactions and humoral responses were also assessed. The trial is registered with ISRCTN, ISRCTN14391248.

FINDINGS

Between April 1 and June 26, 2021, 679 participants were recruited to one of six cohorts, as follows: 129 ChAdOx1 plus cellular quadrivalent influenza vaccine, 139 BNT162b2 plus cellular quadrivalent influenza vaccine, 146 ChAdOx1 plus MF59C adjuvanted, trivalent influenza vaccine, 79 BNT162b2 plus MF59C adjuvanted, trivalent influenza vaccine, 128 ChAdOx1 plus recombinant quadrivalent influenza vaccine, and 58 BNT162b2 plus recombinant quadrivalent influenza vaccine. 340 participants were assigned to concomitant administration of influenza and a second dose of COVID-19 vaccine at day 0 followed by placebo at day 21, and 339 participants were randomly assigned to concomitant administration of placebo and a second dose of COVID-19 vaccine at day 0 followed by influenza vaccine at day 21. Non-inferiority was indicated in four cohorts, as follows: ChAdOx1 plus cellular quadrivalent influenza vaccine (risk difference for influenza vaccine minus placebos -1·29%, 95% CI -14·7 to 12·1), BNT162b2 plus cellular quadrivalent influenza vaccine (6·17%, -6·27 to 18·6), BNT162b2 plus MF59C adjuvanted, trivalent influenza vaccine (-12·9%, -34·2 to 8·37), and ChAdOx1 plus recombinant quadrivalent influenza vaccine (2·53%, -13·3 to 18·3). In the other two cohorts, the upper limit of the 95% CI exceeded the 0·25 non-inferiority margin (ChAdOx1 plus MF59C adjuvanted, trivalent influenza vaccine 10·3%, -5·44 to 26·0; BNT162b2 plus recombinant quadrivalent influenza vaccine 6·75%, -11·8 to 25·3). Most systemic reactions to vaccination were mild or moderate. Rates of local and unsolicited systemic reactions were similar between the randomly assigned groups. One serious adverse event, hospitalisation with severe headache, was considered related to the trial intervention. Immune responses were not adversely affected.

INTERPRETATION

Concomitant vaccination with ChAdOx1 or BNT162b2 plus an age-appropriate influenza vaccine raises no safety concerns and preserves antibody responses to both vaccines. Concomitant vaccination with both COVID-19 and influenza vaccines over the next immunisation season should reduce the burden on health-care services for vaccine delivery, allowing for timely vaccine administration and protection from COVID-19 and influenza for those in need.

FUNDING

National Institute for Health Research Policy Research Programme.

Safety of vaccines used for routine immunization in the United States: An updated systematic review and meta-analysis

BACKGROUND

Understanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines recommended for children, adults, and pregnant women in the United States.

METHODS

We searched the literature in November 2020 to update a 2014 Agency for Healthcare Research and Quality review by integrating newly available data. Studies of vaccines that used a comparator and reported the presence or absence of key adverse events were eligible. Adhering to Evidence-based Practice Center methodology, we assessed the strength of evidence (SoE) for all evidence statements. The systematic review is registered in PROSPERO (CRD42020180089).

RESULTS

Of 56,603 reviewed citations, 338 studies reported in 518 publications met inclusion criteria. For children, SoE was high for no increased risk of autism following measles, mumps, and rubella (MMR) vaccine. SoE was high for increased risk of febrile seizures with MMR. There was no evidence of increased risk of  intussusception with rotavirus vaccine at the latest follow-up (moderate SoE), nor of diabetes (high SoE). There was no evidence of increased risk or insufficient evidence for key adverse events for newer vaccines such as 9-valent human papillomavirus and meningococcal B vaccines. For adults, there was no evidence of increased risk (varied SoE) or insufficient evidence for key adverse events for the new adjuvanted inactivated influenza vaccine and recombinant adjuvanted zoster vaccine. We found no evidence of increased risk (varied SoE) for key adverse events among pregnant women following tetanus, diphtheria, and acellular pertussis vaccine, including stillbirth (moderate SoE).

CONCLUSIONS

Across a large body of research we found few associations of vaccines and serious key adverse events; however, rare events are challenging to study. Any adverse events should be weighed against the protective benefits that vaccines provide.

Clinical practice guidelines 2019: Indian consensus-based recommendations on pneumococcal vaccination for adults

Similar to the global scenario, pneumococcal diseases are a significant health concern in India. Pneumococcal diseases occur frequently among adults and are largely preventable through vaccines. Globally, several guidelines and recommendations are available for pneumococcal vaccination in adults. However, owing to wide variations in the disease burden, regulatory landscape, and health-care system in India, such global guidelines cannot be unconditionally implemented throughout the country. To address these gaps, the Indian Chest Society and National College of Chest Physicians of India jointly conducted an expert meeting in January 2019. The aim of the discussion was to lay down specific evidence-based recommendations on adult pneumococcal vaccination for the country, with a view to further ameliorate the disease burden in the country. This article presents an overview of the closed-door discussion by the expert members on clinical practice guidelines to be followed for adult pneumococcal vaccination in India.

Immunogenicity and safety of 13-valent pneumococcal conjugate vaccine in HIV-infected adults in the era of highly active antiretroviral therapy: analysis stratified by CD4 T-cell count

HIV-infected patients are 30- to 100-fold more susceptible to invasive pneumococcal diseases than are healthy adults. Pneumococcal vaccination may be the best way to decrease the large pneumococcal disease burden, but the optimal timing of vaccination is still unclear. In this study, HIV-infected subjects aged ≥18 years were recruited and divided into 2 age-matched groups: group 1 (subjects with CD4 T-cell count ≥350 cells/µL) and group 2 (CD4 T-cell count <350 cells/µL). Multiplex opsonophagocytic killing assay was used to compare immunogenicity after immunization with 13-valent pneumococcal conjugate vaccine (PCV13). Among 70 subjects, 67 (group 1, N = 34; group 2, N = 33) were available for the assessment of immunogenicity and safety. With respect to the post-vaccination geometric mean titer (GMT) ratios, the non-inferiority criteria were not met. Post-vaccination GMTs were significantly lower in group 2 compared to group 1 for all 4 pneumococcal serotypes (5, 6B, 18C, and 19A) tested. PCV13 was safe and well tolerated in HIV-infected patients irrespective of immune status. In conclusion, PCV13 showed significantly inferior immunogenicity among HIV-infected patients with CD4 T-cell count <350 cells/µL compared to those with a higher CD4 T-cell count.

Comparative Immunogenicity of Enhanced Seasonal Influenza Vaccines in Older Adults: A Systematic Review and Meta-analysis

BACKGROUND

A number of enhanced influenza vaccines have been developed for use in older adults, including high-dose, MF59-adjuvanted, and intradermal vaccines.

METHODS

We conducted a systematic review examining the improvements in antibody responses measured by the hemagglutination inhibition assay associated with these enhanced vaccines, compared with each other and with the standard-dose (SD) vaccine using random effects models.

RESULTS

Thirty-nine trials were included. Compared with adults aged ≥60 years receiving SD vaccines, those receiving enhanced vaccines had significantly higher postvaccination titers (for all vaccine strains) and higher proportions with elevated titers ≥40 (for most vaccine strains). High-dose vaccine elicited 82% higher postvaccination titer to A(H3N2) compared with SD vaccine; this was significantly higher than the 52% estimated for MF59-adjuvanted versus SD vaccines (P = .04), which was higher than the 32% estimated for intradermal versus SD vaccines (P < .01).

CONCLUSIONS

Overall, by summarizing current evidence, we found that enhanced vaccines had greater antibody responses than the SD vaccine. Indications of differences among enhanced vaccines highlight the fact that further research is needed to compare new vaccine options, especially during seasons with mismatched circulating strains and for immune outcomes other than hemagglutination inhibition titers as well as vaccine efficacy.

Efficacy and Safety of the Pneumococcal Conjugate-13 Valent Vaccine in Adults

Invasive pneumococcal disease and pneumococcal pneumonia cause substantial morbidity and mortality in the elderly. This review focuses on the immunogenicity, safety, efficacy and effectiveness data on the use of the 13-valent conjugate pneumococcal vaccine (PCV13) in adults. A MEDLINE literature search was performed from January 1946 to December 2017. Additional references were identified from a review of literature citations. All English-language randomized trials, observational studies and meta-analyses assessing the immunogenicity, efficacy, effectiveness and safety of PCV13 in adults were evaluated. Six randomized controlled studies evaluated immunogenicity and safety of PCV13 in adults and showed that the conjugated vaccine elicited a greater immune response to the majority of the 13 serotypes compared to the 23-valent polysaccharide pneumococcal vaccine (PPV23). Administering PCV13 prior to PPV23 elicits greater immune responses and multiple doses of PCV13 demonstrated modest advantage. PCV13 titers declined after a year but remained above baseline. A randomized clinical trial (CAPiTA) showed that PCV13 was effective in preventing community-acquired pneumonia (CAP) and vaccine-type invasive pneumococcal disease, but not any cause pneumonia. Safety data shows PCV13 elicits minor local reactions, such as pain at the injection site. Major side effects that were commonly reported included muscle fatigue and headache. Both local and systemic adverse events were comparable to PPV23. While PCV13 has a well-established immunogenicity and safety profile in adults, there is sparse data on sequential or multiple dosing, efficacy and effectiveness in adults. As there are few countries who have adopted PCV13 for routine adult immunization, there is a need to evaluate the effectiveness of PCV13 in a real-world setting.

Immunogenicity and safety of a tetanus-diphtheria vaccine and a 13-valent pneumococcal conjugate vaccine after concomitant vaccination in ≥ 50-year-old adults

BACKGROUND

When two or more vaccines are administered concurrently, there is concern about safety and immunogenicity from vaccine interaction.

METHODS

Subjects aged ≥50 years were randomized 1:1:1 to receive tetanus-diphtheria (Td) + 13-valent pneumococcal conjugate vaccine (PCV13; Group 1), PCV13 alone (Group 2), or Td alone (Group 3). After single or concomitant vaccination, enzyme-linked immunosorbent assay and opsonophagocytic assay (OPA) were performed to compare immunogenicity for Td and PCV13, respectively.

RESULTS

A total of 448 subjects were available for the assessment. After concomitant administration, the non-inferiority criteria of geometric mean titer (GMT) ratios were met for tetanus, diphtheria, and all four pneumococcal serotypes (1, 5, 18C, and 19A). However, subjects in Group 3 (Td alone) were more likely to have a high IgG anti-tetanus antibody titer (≥ 0.5 U/mL) than those in Group 1 (Td + PCV13) (p <  0.01). As for the pneumococcal serotype 1, the OPA GMT was significantly higher in Group 1 (PCV13 + Td) compared to Group 2 (PCV13 alone) (p = 0.02). No serious adverse event occurred.

CONCLUSIONS

Concomitant Td and PCV13 administration induced sufficient immunity without significant interference and showed good safety profiles.

TRIALS REGISTRATION

NCT03552445 registered at http://www.clinicaltrials.gov on June 11, 2018 (retrospectively registered).

Comparison of three sample size calculation methods for non-inferiority vaccine trials with multiple continuous co-primary endpoints

Clinical trials that study immunogenicity of combination vaccines often have less power than desirable. To make up for the reduction in statistical power at the study level, researchers have to increase the study sample size. To study immunogenicity variables, we used the geometric mean concentration of immune response after vaccination as immunologic endpoint and compared 3 sample size calculation methods: the "Inflation factors" method, the "Incrementing" method, and the "Bonferroni correction" method when there are multiple continuous co-primary endpoints. The parameters were set according to the actual situation of the use of combination vaccines and the simulation results were used as reference. The present study demonstrates that all 3 methods are applicable when the effect size of each endpoint is similar and the endpoints are at most weakly correlated, but when there is a true difference in effect sizes among endpoints, the "Incrementing" method has the best performance.

A systematic review and meta-analysis on the safety of newly adjuvanted vaccines among older adults

INTRODUCTION

New adjuvants have been developed to improve the efficacy of vaccines and for dose-sparing capacity and may overcome immuno senescence in the elderly. We reviewed the safety of newly-adjuvanted vaccines in older adults.

METHODS

We searched Medline for clinical trials (CTs) including new adjuvant systems (AS01, AS02, AS03, or MF59), used in older adults, published between 01/1995 and 09/2017. Safety outcomes were: serious adverse events (SAEs); solicited local and general AEs (reactogenicity); unsolicited AEs; and potentially immune-mediated diseases (pIMDs). Standard random effects meta-analyses were conducted by type of safety event and adjuvant type, reporting Relative Risks (RR) with 95% confidence intervals (95% CI).

RESULTS

We identified 1040 publications, from which we selected 7, 7, and 12 CTs on AS01/AS02, AS03 and MF59, respectively. 47,602 study participants received newly-adjuvanted vaccine and 44,521 control vaccine, or placebo. Rates of SAEs (RR = 0.99, 95% CI = 0.96-1.02), deaths (RR = 0.99, 95% CI = 0.92-1.06) and pIMDs (RR = 0.94, 95% CI = 0.79-1.1) were comparable in newly-adjuvanted and control groups. Vaccine-related SAEs occurred in <1% of the subjects in both groups. The reactogenicity of AS01/AS02 and AS03 adjuvanted vaccines was higher compared to control vaccines, whereas MF59-adjuvanted vaccines resulted only in more pain. Grade 3 reactogenicity was reported infrequently, with fatigue (RR = 2.48, 95% CI = 1.69-3.64), headache (RR = 2.94, 95% CI = 1.24-6.95), and myalgia (RR = 2.68, 95% CI = 1.86-3.80) occurring more frequently in newly-adjuvanted groups. Unsolicited AEs occurred slightly more frequently in newly-adjuvanted groups (RR = 1.04, 95% CI = 1.00-1.08).

CONCLUSIONS

Our review suggests that, within the clinical trial setting, the use of new adjuvants in older adults has not led to any safety concerns, with no increase in SAEs or fatalities. Higher rates for solicited AEs were observed, especially for AS01/AS02 and AS03 adjuvanted vaccines, but AEs were mostly mild and transient. Further evidence will need to come from the use of new adjuvants in the real-world setting, where larger numbers can be studied to potentially detect rare reactions.

Cost-effectiveness analysis of different seasonal influenza vaccines in the elderly Italian population

In the perspective of reaching at least 75% influenza vaccination coverage in the elderly and substantial budget constraints, Italian decision makers are facing important challenges in determining an optimal immunization strategy for this growing and particularly vulnerable population. Four different influenza vaccines are currently available for Italian older adults aged 65 years or above, namely trivalent inactivated vaccines (TIVs), MF59-adjuvanted TIV (MF59-TIV), intradermal TIV (ID-TIV) and quadrivalent inactivated vaccines (QIVs). The present study is the first to compare the cost-effectiveness profiles of virtually all possible public health strategies, including the aforementioned four vaccine formulations as well non-vaccination. For this purpose, a decision tree model was built ex novo; the analysis was conducted from the third-payer perspective in the timeframe of one year. All available vaccines were cost-effective compared with non-vaccination. However, MF59-TIV had the most favorable economic profile in the Italian elderly population. Indeed, compared with non-vaccination, it was deemed highly cost-effective with an incremental cost-effectiveness ratio (ICER) of €10,750 per quality-adjusted life year (QALY). The ICER was much lower (€4,527/QALY) when MF59-TIV was directly compared with TIV. ID-TIV and QIV were dominated by MF59-TIV as the former comparators were associated with greater total costs and lower health benefits. Both deterministic and probabilistic sensitivity analyses confirmed robustness of the base case results. From the economic perspective, MF59-TIV should be considered as a preferential choice for Italian older adults aged 65 years or above.

Tetanus-diphtheria-pertussis vaccine may suppress the immune response to subsequent immunization with pneumococcal CRM197-conjugate vaccine (coadministered with quadrivalent meningococcal TT-conjugate vaccine): a randomized, controlled trial⋆

BACKGROUND

: Due to their antigenic similarities, there is a potential for immunological interaction between tetanus/diphtheria-containing vaccines and carrier proteins presented on conjugate vaccines. The interaction could, unpredictably, result in either enhancement or suppression of the immune response to conjugate vaccines if they are injected soon after or concurrently with diphtheria or tetanus toxoid. We examined this interaction among adult Australian travellers before attending the Hajj pilgrimage of 2015.

METHODS

We randomly assigned each participant to one of three vaccination schedules. Group A received tetanus, diphtheria and acellular pertussis vaccine (Tdap) 3-4 weeks before receiving CRM197-conjugated 13-valent pneumococcal vaccine (PCV13) coadministered with TT-conjugated quadrivalent meningococcal vaccine (MCV4). Group B received all three vaccines concurrently. Group C received PCV13 and MCV4 3-4 weeks before Tdap. Blood samples collected at baseline, at each vaccination visit and 3-4 weeks after vaccination were tested for the pneumococcal opsonophagocytic assay (OPA).

RESULTS

A total of 166 participants aged 18-64 (median 42) years were recruited, 159 completed the study. Compared with the other groups, Group A had significantly ( P  <   0.05) lower geometric mean titres (GMTs) post-vaccination in seven serotypes of PCV13 (1, 3, 4, 5, 14, 18C and 9V). Additionally, Group A had lower frequency of serorises (≥ 4-fold rise in OPA titres) in serotype5 (79%, p = 0.01) and 18C (73.5%, p = 0.06); whereas Groups B and C had significantly lower frequencies of serorises in Serotype 4 (82%) and 6A (73.5%), respectively. No statistically significant difference was detected across the three groups in frequencies achieving OPA titre ≥ 1:8 post-vaccination.

CONCLUSIONS

Tdap vaccination 3-4 weeks before administration of PCV13 and MCV4 significantly reduced the GMTs to seven of the 13 pneumococcal serotypes in adults. If multiple vaccination is required before travel, deferring tetanus/diphtheria until after administering the conjugate vaccine is recommended to avoid immune interference.