Disparate kinetics in immune response of two different Haemophilus influenzae type b conjugate vaccines: Immunogenicity and safety observations from a randomized controlled phase IV study in healthy infants and toddlers using a 2+1 schedule

Since the introduction of Haemophilus Influenzae type b (Hib) conjugate vaccines, invasive Hib disease has strongly declined worldwide, yet continued control of Hib disease remains important. In Europe, currently three different hexavalent combination vaccines containing Hib conjugates are marketed. In this phase IV, single-blind, randomized, controlled, multi-country study (NCT04535037), we aimed to compare, in a 2 + 1 vaccination schedule, the immunogenicity and safety and show non-inferiority, as well as superiority, of DTPa-HBV-IPV/Hib (Ih group) versus DTaP5-HB-IPV-Hib (Va group) in terms of anti-polyribosylribitol phosphate (PRP) antibody geometric mean concentrations (GMCs) and proportion of participants reaching anti-PRP antibody concentrations greater than or equal to a threshold of 5 µg/mL. One month after the booster vaccination, the anti-PRP antibody GMC ratio (Ih group/Va group) was 0.917 (95% CI: 0.710-1.185), meeting the non-inferiority criteria. The difference in percentage of participants (Ih group - Va group) reaching GMCs ≥5 µg/mL was -6.3% (95% CI: -14.1% to 1.5%), not reaching the predefined non-inferiority threshold. Interestingly, a slightly higher post-booster antibody avidity was observed in the Ih group versus the Va group. Both vaccines were well tolerated, and no safety concerns were raised. This study illustrates the different kinetics of the anti-PRP antibody response post-primary and post-booster using the two vaccines containing different Hib conjugates and indicates a potential differential impact of concomitant vaccinations on the anti-PRP responses. The clinical implications of these differences should be further studied.

Molecular epidemiology of pneumococcal carriage in children from Seville, following implementation of the PCV13 immunization program in Andalusia, Spain

INTRODUCTION

The 13-valent pneumococcal conjugate vaccine (PCV13) universal vaccination programme was introduced in December 2016 in Andalusia.

METHODS

A cross-sectional study was conducted on the molecular epidemiology of pneumococcal nasopharyngeal colonization. A total of 397 healthy children were recruited from primary healthcare centres in Seville for the periods 1/4/2018 to 28/2/2020 and 1/11/2021 to 28/2/2022 (PCV13 period). Data from a previous carriage study conducted among healthy and sick children from 1/01/2006 to 30/06/2008 (PCV7 period), were used for comparison of serotype/genotype distributions and antibiotic resistance rates.

RESULTS

Overall, 76 (19%) children were colonized with S. pneumoniae during the PCV13 period and there were information available from 154 isolates collected during the PCV7 period. Colonization with PCV13 serotypes declined significantly in the PCV13 period compared with historical controls (11% vs 38%, p = 0.0001), being serotypes 19F (8%), 3 (1%) and 6B (1%) the only circulating vaccine types. Serotypes 15B/C and 11A were the most frequently identified non-PCV13 serotypes during the PCV13 period (14% and 11%, respectively); the later one increased significantly between time periods (p = 0.04). Serotype 11A was exclusively associated in the PCV13 period with ampicillin-resistant variants of the Spain9V-ST156 clone (ST6521 and genetically related ST14698), not detected in the preceding period.

CONCLUSIONS

There was a residual circulation of vaccine types following PCV13 introduction, apart from serotype 19F. Serotype 11A increased between PCV13 and PCV7 periods due to emergence and clonal expansion of ampicillin-resistant genotype ST6521.

Safety and Immunogenicity of a ChAd155-Vectored Respiratory Syncytial Virus Vaccine in Infants 6-7 Months of age: A Phase 1/2 Randomized Trial

BACKGROUND

Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections in infants. This phase 1/2, observer-blind, randomized, controlled study assessed the safety and immunogenicity of an investigational chimpanzee-derived adenoviral vector RSV vaccine (ChAd155-RSV, expressing RSV F, N, and M2-1) in infants.

METHODS

Healthy 6- to 7-month-olds were 1:1:1-randomized to receive 1 low ChAd155-RSV dose (1.5 × 1010 viral particles) followed by placebo (RSV_1D); 2 high ChAd155-RSV doses (5 × 1010 viral particles) (RSV_2D); or active comparator vaccines/placebo (comparator) on days 1 and 31. Follow-up lasted approximately 2 years.

RESULTS

Two hundred one infants were vaccinated (RSV_1D: 65; RSV_2D: 71; comparator: 65); 159 were RSV-seronaive at baseline. Most solicited and unsolicited adverse events after ChAd155-RSV occurred at similar or lower rates than after active comparators. In infants who developed RSV infection, there was no evidence of vaccine-associated enhanced respiratory disease (VAERD). RSV-A neutralizing titers and RSV F-binding antibody concentrations were higher post-ChAd155-RSV than postcomparator at days 31, 61, and end of RSV season 1 (mean follow-up, 7 months). High-dose ChAd155-RSV induced stronger responses than low-dose, with further increases post-dose 2.

CONCLUSIONS

ChAd155-RSV administered to 6- to 7-month-olds had a reactogenicity/safety profile like other childhood vaccines, showed no evidence of VAERD, and induced a humoral immune response. Clinical Trials Registration. NCT03636906.

Penta- and hexavalent vaccination of extremely and very-to-moderate preterm infants born at less than 34 weeks and/or under 1500 g: A systematic literature review

Debate regarding vaccinating high-risk infants with penta- and hexavalent vaccines persists, despite their good immunogenicity and acceptable safety profile in healthy full-term infants. We report the findings of a systematic literature search that aimed to present data on the immunogenicity, efficacy, effectiveness, safety, impact, compliance and completion of penta- and hexavalent vaccination in high-risk infants, including premature newborns. Data from the 14 studies included in the review showed that the immunogenicity and the safety profile of penta- and hexavalent vaccines in preterm infants was generally similar to those seen in full-term infants, with the exception of an increase in cardiorespiratory adverse events such as apnea, bradycardia and desaturation following vaccination in preterm infants. Despite recommendations of vaccinating preterm infants according to their actual age, and the relatively high completion rate of the primary immunization schedule, vaccination was often delayed, increasing the vulnerability of this high-risk population to vaccine-preventable diseases.

Enhanced safety surveillance of GSK's quadrivalent seasonal influenza vaccine in Germany and Spain (2021/2022 season) using an electronic patient‐reported outcome system for vaccine safety remote monitoring

Background

Seasonal influenza epidemics are managed through vaccination each winter in the European Union, to prevent infections, complications, and deaths. As circulating virus strains vary unpredictably, vaccines are reformulated annually, and their safety monitored rapidly and continuously at the start of each season, following European Medicines Agency guidelines.Seasonal influenza epidemics are managed through vaccination each winter in the European Union, to prevent infections, complications, and deaths. As circulating virus strains vary unpredictably, vaccines are reformulated annually, and their safety monitored rapidly and continuously at the start of each season, following European Medicines Agency guidelines.

Methods

This enhanced safety surveillance study assessed pre‐specified and other adverse events (AEs) occurring within 7 days of GSK's inactivated quadrivalent seasonal influenza vaccine (IIV4) in children and adults in Spain and Germany. As the study was conducted during the COVID‐19 pandemic (2021/2022 season), data were collected electronically, using a web portal or call center.

Results

Safety was assessed in 737 participants (median age 49 and 9 years in Germany and Spain, respectively, 19.3% with a chronic medical condition). After Dose 1 and Dose 2, respectively, 332 (45.1%) and 5 (26.3%) participants reported at least one AE, primarily pre‐specified AEs. The most common AEs after Dose 1 (adults and children) were injection site pain, swelling or erythema, headache, and fatigue. After Dose 2 (in children), the most common AEs were injection site pain, rhinorrhea, fatigue, and decreased appetite. No new or unexpected safety issues were identified.

Conclusion

This study supports and confirms the safety profile of GSK's IIV4 in all age groups with a vaccine indication. The new electronic safety reporting method (with response rates of 75.4% following Dose 1 and 100% following Dose 2) provides an alternative for future studies to reduce the burden on sites or in case site visits are not feasible.

HPV knowledge and vaccine acceptability: a survey-based study among parents of adolescents (KAPPAS study)

Background

Human papillomavirus (HPV) infection is recognized as one of the major causes of infection-related cancer worldwide. In Spain, the HPV vaccination program started in 2007 and until 2022, it targeted 12-year-old girls.

Methods

This was a cross-sectional, multicenter survey-based research carried out at 24 pediatric offices to describe HPV knowledge and vaccine acceptability in parents of children aged between 9 and 14 years-old in Spain. Parents were randomly selected from the medical records following specific quotas to ensure representativeness. The survey included five sections that aim to collect information about sociodemographic characteristics, knowledge of HPV, knowledge and acceptability of vaccines in general, HPV vaccination knowledge and HPV vaccine acceptability. Each section was constituted by a number of close questions with different answer options. Specific scores were assigned to each possible answer to these questions. Based on these scores, four composite variables were created to assess HPV knowledge, HPV vaccine knowledge, HPV vaccine acceptability and vaccines knowledge and acceptability in general. A latent class analysis was performed to identify different group of respondents according to their HPV vaccine acceptability.

Results

A total of 1405 valid surveys were included, with 86.19% of the respondents being mothers. The mean score of HPV knowledge was 28.92 out of 40 (maximum value) (95% CI 28.70–29.20) and the mean score of HPV vaccine acceptability was 3.37 out of 5 (maximum value). One third of parents still need more information to take a final decision about HPV vaccination in their children. Parents perceived that females were more likely to become infected than males and tended to associate HPV infection mainly with cervical cancer, showing a. a lack of information about other HPV-related diseases affecting males.

Conclusions

This study results highlight the need for future actions and educational initiatives to raise awareness of HPV consequences in both genders and to contribute to achieving the elimination of HPV-related diseases beyond cervical cancer.

Factors influencing HPV knowledge and vaccine acceptability in parents of adolescent children: results from a survey-based study (KAPPAS study)

Human Papillomavirus (HPV) is one of the most common sexually transmitted infections associated with a wide range of diseases and cancers that may affect both genders. Since 2007, the Spanish National Immunization Program includes HPV vaccination, and currently it only targets 12-year-old girls. The objective of our study is to assess differences in the knowledge of HPV and HPV vaccine acceptability according to different factors, and to identify the role of different sources of information. A cross-sectional, multicenter survey research was carried out in twenty-four pediatric offices in Spain, and included parents of children aged 9 to 14 years old. 1,405 valid survey-responses were considered for the analysis. Parental awareness of HPV and HPV vaccine, as well as vaccine acceptability, are still strongly associated with child gender (girls) and age (12–14 years old). HPV knowledge and HPV vaccine acceptability are related to parental gender, HPV vaccination status and having at least one daughter. Parents who consulted a healthcare source to obtain further information about HPV had greater HPV and HPV vaccine knowledge and acceptability. HPV and HPV vaccine awareness and acceptability are strongly associated with child gender and age, which correlates with the current immunization program.

Brand-Specific Enhanced Safety Surveillance Study of GSK's Quadrivalent Seasonal Influenza Vaccine, Conducted During the COVID-19 Pandemic, in Belgium, Germany and Spain, for the 2020/21 Season

INTRODUCTION

Seasonal influenza poses a major public health burden worldwide. Influenza vaccines, updated yearly to match circulating strains based on World Health Organization (WHO) recommendations, are the cornerstone of prevention and require regular monitoring. The COVID-19 pandemic is expected to cause logistical, site access and medical staff constraints and could affect the safety profile of influenza vaccines.

METHODS

Following European Medicines Agency guidance, an enhanced safety surveillance (ESS) study assessed the frequency and severity of predefined and other adverse events (AEs) occurring within 7 days of receiving GSK's inactivated quadrivalent seasonal influenza vaccine (IIV4), in Belgium, Germany and Spain in 2020/21, using adverse drug reaction (ADR) cards.

RESULTS

During the 2020/21 influenza season, 1054 participants vaccinated with GSK's IIV4 were enrolled (all adults in Belgium and Germany, 30% adults/70% children in Spain); 96 eligible children received a second dose. Overall, 1042 participants completed the study. After doses 1 and 2, 98.9% and 100% of participants, respectively, returned their completed ADR card. After doses 1 and 2, 37.8% (398/1054) and 13.5% (13/96) of participants, respectively, reported at least one AE. The most frequently reported categories of AEs were "general disorders and administration site conditions" (e.g. injection site pain) and "nervous system disorders" (e.g. headache). There were no deaths or serious AEs deemed related to GSK's IIV4.

CONCLUSION

This ESS study assessed AEs in near real time. The COVID-19 pandemic did not alter the safety profile of GSK's IIV4. No safety signals were detected during the study, which confirms the excellent safety profile of GSK's IIV4.

Safety Profile of GSK's Inactivated Quadrivalent Seasonal Influenza Vaccine in Belgium, Germany and Spain: Passive Enhanced Safety Surveillance Study for the 2019/2020 Influenza Season

Introduction

Seasonal influenza infects millions annually in Europe. Annual influenza vaccination is the most effective measure to reduce the risk of infection and its complications, especially among young children and older adults.

Objective

We assessed adverse event (AE) frequency after receiving GSK’s inactivated quadrivalent seasonal influenza vaccine (IIV4).

Methods

A passive enhanced safety surveillance study was conducted in Belgium, Germany, and Spain. Adults who had received GSK's IIV4 or the parent(s)/guardian(s)/legally acceptable representative(s) of children given the vaccine were invited to complete an adverse drug reaction (ADR) card to document AEs experienced within 7 days post vaccination.

Results

A total of 1082 participants (51.6% females) received GSK's IIV4, including 115 children < 9 years of age who received two doses. The ADR card return rate was 97.0% (n = 1049) after dose 1 and 100% (n = 115) after dose 2. All participants in Belgium and Germany were adults. In Spain, 71.2% were children. After dose 1, 39.2% reported one or more AE. The most frequent AEs category was "general disorders and administration site conditions” (GDASC). AEs were most frequently reported in adults aged 18–65 years (47.2%), followed by children aged 6 months–17 years (38.1%), and adults aged > 65 years (31.6%). After dose 2, 7.8% reported one or more AE, and GDASC was again the most frequent AE category. There were no serious AEs related to GSK's IIV4 within 7 days post vaccination.

Conclusion

No serious AEs related to GSK’s IIV4 within 7 days post vaccination were reported. This study supports the favourable risk–benefit safety profile of GSK’s IIV4.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01121-8.

Seasonal influenza infects millions annually in Europe, especially young children and older adults. Annual influenza vaccination is the most effective measure to reduce the risk of infection and its complications. As the wild influenza virus strains change every year, the composition of the influenza vaccine changes as well. Since the vaccine is produced in the same way over the years, extensive safety studies are no longer required by regulatory authorities. Instead, monitoring of any unwanted medical incidents (adverse events) after vaccination is required. For the 2019/2020 season, we monitored the adverse events reported by a representative sample of people in Belgium, Germany, and Spain within 7 days after receiving GSK's seasonal influenza vaccine.

Of the 1082 people who received the first dose of the vaccine, 39% reported at least one adverse event, such as pain and swelling at the injection site, tiredness, fever, headache, or dizziness. A total of 115 children under 9 years of age received two doses 4 weeks apart. After their second dose, few of these children (8%) reported adverse events. The most frequent adverse events were fever, swelling and pain at the injection site, runny nose, or irritability. No serious adverse events were reported after either the first or second dose.

No serious adverse events related to GSK’s seasonal influenza vaccine within the 7 days after vaccination were reported. This study supports the favourable risk–benefit safety profile of GSK's seasonal influenza vaccine.

Immunological non-inferiority of a new fully liquid presentation of the MenACWY-CRM vaccine to the licensed vaccine: results from a randomized, controlled, observer-blind study in adolescents and young adults

A fully liquid MenACWY-CRM vaccine presentation has been developed, modifying the meningococcal serogroup A (MenA) component from lyophilized to liquid. The safety and immunogenicity of the liquid presentation at the end of the intended shelf-life (aged for 24 or 30 months) were compared to the licensed lyophilized/liquid presentation. This multicenter, randomized (1:1), observer-blind, phase 2b study (NCT03433482) enrolled adolescents and young adults (age 10-40 years). In part 1, 844 participants received one dose of liquid presentation stored for approximately 24 months or licensed presentation. In part 2, 846 participants received one dose of liquid presentation stored for approximately 30 months or licensed presentation. After storage, the MenA free saccharide (FS) level was approximately 25% and O-acetylation was approximately 45%. The primary objective was to demonstrate non-inferiority of the liquid presentation to licensed presentation, as measured by human serum bactericidal assay (hSBA) geometric mean titers (GMTs) against MenA, 1-month post-vaccination. Immune responses against each vaccine serogroup were similar between groups. Between-group ratios of hSBA GMTs for MenA were 1.21 (part 1) and 1.11 (part 2), with two-sided 95% confidence interval lower limits (0.94 and 0.87, respectively) greater than the prespecified non-inferiority margin (0.5), thus meeting the primary study objective. No safety concerns were identified. Despite reduced O-acetylation of MenA and increased FS content, serogroup-specific immune responses induced by the fully liquid presentation were similar to those induced by the licensed MenACWY-CRM vaccine, with non-inferior anti-MenA responses. The safety profiles of the vaccine presentations were similar.

Brand-Specific Enhanced Safety Surveillance of GSK's Quadrivalent Seasonal Influenza Vaccine in Belgium, Germany and Spain for the 2018/2019 Season

Introduction

Seasonal influenza causes numerous deaths worldwide each year. Annual vaccination for disease prevention is crucial. Seasonal vaccines are updated each year to closely match circulating strains.

Objective

To comply with European Medicines Agency (EMA) guidance, an enhanced safety study was conducted to rapidly collect and assess adverse events (AEs) within 7 days following vaccination with GSK’s inactivated quadrivalent seasonal influenza vaccine (IIV4) in 2018/2019.

Methods

A customised AE reporting card (AERC) and standardised electronic data reporting application were used in Belgium, Germany and Spain in adult and paediatric subjects in this study.

Results

In 2018, 1060 subjects vaccinated with one dose of GSK’s IIV4 were enrolled (all subjects in Belgium and Germany were adults, and 75% and 25% of subjects in Spain were children and adults, respectively). In Spain, 139 eligible children later received a second dose. Overall 1035 subjects completed the study. After dose 1 and dose 2, 98.3% and 100% of subjects, respectively, returned the completed AERC. Over the study period, 43.0% (456/1060 post dose 1) and 23.7% (33/139 post dose 2) of subjects reported at least one AE within 7 days after immunisation. The most frequently reported categories of AEs were General and Administration Site (e.g. injection site pain, swelling, erythema) and Respiratory Disorders (e.g. rhinorrhoea, cough, nasal congestion). There were no deaths and no serious AEs deemed related to GSK’s IIV4.

Conclusion

In compliance with EMA guidance, this study design allowed for near real-time assessment of AEs. No safety signals were detected at any point during the study period. The study supports and confirms the acceptable safety profile of GSK’s IIV4.

ClinicalTrials.gov identifier

NCT03688620.

HPV knowledge and vaccine acceptance among European adolescents and their parents: a systematic literature review

BACKGROUND

Since the introduction of HPV vaccines, several studies have been conducted in different countries to assess HPV knowledge and vaccine acceptance. The aim of this study was to perform a systematic literature review to summarize results and identify factors associated with HPV knowledge and vaccine acceptance in adolescents and their parents and to compile the measurement tools used in the published research studies performed in European countries where HPV is licensed.

METHODS

A systematic literature review was conducted for studies published between January 1st 2006 and December 31st 2017.

RESULTS

Seventy non-interventional studies performed in 16 European countries met the inclusion criteria. Thirty-eight of them reported data on HPV knowledge and 40 reported data on HPV vaccine acceptance. Further, 51.8% of adolescents (range 0% to 98.6%) and 64.4% of parents (range 1.7% to 99.3%) knew about HPV infection. Insufficient information and safety concerns were the main barriers to vaccination acceptance.

CONCLUSION

HPV knowledge and vaccine acceptance are still modest and vary widely between studies across EU countries. Coordinated efforts should be made to provide the relevant population with information for informed decision-making about HPV vaccination.

Immunogenicity and safety of porcine circovirus-free human rotavirus vaccine in healthy infants: a phase III, randomized trial

BACKGROUND

Porcine circovirus type 1 (PCV-1) material was detected in the human rotavirus vaccine (HRV) in 2010. In this study (NCT02914184) we compared immunogenicity and safety of the PCV-free HRV vaccine (PCV-free HRV) with HRV. PCV-free HRV is an HRV with no detection of PCV-1 and PCV-2 according to the limit of detection of the tests used.

METHODS

Healthy infants 6-12 weeks of age were randomized (1:1:1:1) to receive 2 doses of 1 of the 3 lots of PCV-free HRV or HRV. The study objectives were to demonstrate lot-to-lot consistency of the PCV-free HRV and non-inferiority of PCV-free HRV as compared to HRV in terms of immunogenicity, 1-2 months post-dose 2. Reactogenicity and safety were also assessed.

RESULTS

Overall, 1612 infants were enrolled and 1545 completed the study. Study objectives were demonstrated since the pre-defined criteria were met. Among participants receiving PCV-free HRV and HRV, 79.27% and 81.76% seroconverted and geometric mean concentrations were 159.5 and 152.8 U/mL, respectively. The incidences of adverse events and serious adverse events were similar between the pooled PCV-free HRV and HRV groups.

CONCLUSIONS

The 3 PCV-free HRV lots demonstrated consistency and PCV-free HRV was non-inferior compared to HRV in terms of immunogenicity.

Prevention of vaccine-matched and mismatched influenza in children aged 6-35 months: a multinational randomised trial across five influenza seasons

BACKGROUND

Despite the importance of vaccinating children younger than 5 years, few studies evaluating vaccine prevention of influenza have been reported in this age group. We evaluated efficacy of an inactivated quadrivalent influenza vaccine (IIV4) in children aged 6-35 months.

METHODS

In this phase 3, observer-blinded, multinational trial, healthy children from 13 countries in Europe, Central America, and Asia were recruited in five independent cohorts, each in a different influenza season. Participants were randomly assigned (1:1) to either IIV4 (15 μg haemagglutinin antigen per strain per 0·5 mL dose; a single dose on day 0 for vaccine-primed children, and two doses, on days 0 and 28, for vaccine-unprimed children) or to one or two doses of a non-influenza control vaccine. Primary endpoints were moderate-to-severe influenza or all influenza (irrespective of disease severity) confirmed by RT-PCR on nasal swabs. Cultured isolates were further characterised as antigenically matched or mismatched to vaccine strains. Efficacy was assessed in the per-protocol cohort and total vaccinated cohort (time-to-event analysis), and safety was assessed in the total vaccinated cohort.

FINDINGS

Between Oct 1, 2011, and Dec 31, 2014, 12 018 children were recruited into the total vaccinated cohort (6006 children in the IIV4 group and 6012 children in the control group). 356 (6%) children in the IIV4 group and 693 (12%) children in the control group had at least one case of RT-PCR-confirmed influenza. Of these 1049 influenza strains, 138 (13%) were A/H1N1, 529 (50%) were A/H3N2, 69 (7%) were B/Victoria, and 316 (30%) were B/Yamagata. Overall, 539 (64%) of 848 antigenically characterised isolates were vaccine-mismatched (16 [15%] of 105 for A/H1N1; 368 [97%] of 378 for A/H3N2; 54 [86%] of 63 for B/Victoria; 101 [33%] of 302 for B/Yamagata). Vaccine efficacy was 63% (97·5% CI 52-72) against moderate-to-severe influenza and 50% (42-57) against all influenza in the per-protocol cohort, and 64% (53-73) against moderate-to-severe influenza and 50% (42-57) against all influenza in the total vaccinated cohort. There were no clinically meaningful safety differences between IIV4 and control.

INTERPRETATION

IIV4 prevented influenza A and B in children aged 6-35 months despite high levels of vaccine mismatch. Vaccine efficacy was highest against moderate-to-severe disease, which is the most clinically important endpoint associated with greatest burden.

FUNDING

GlaxoSmithKline Biologicals SA.

[Bacterial etiology of acute otitis media in Spain in the post-pneumococcal conjugate vaccine era]

INTRODUCTION

Acute otitis media (AOM) is common in children aged <3 years. A pneumococcal conjugate vaccine (PCV) (PCV7; Prevenar, Pfizer/Wyeth, USA) has been available in Spain since 2001, which has a coverage rate of 50-60% in children aged <5 years.

MATERIALS AND METHODS

Children aged ≥3 to 36 months with AOM confirmed by an ear-nose-throat specialist were enrolled at seven centers in Spain (February 2009-May 2012) (GSK study identifier: 111425). Middle-ear-fluid samples were collected by tympanocentesis or spontaneous otorrhea and cultured for bacterial identification. Culture-negative samples were further analyzed using polymerase chain reaction (PCR).

RESULTS

Of 125 confirmed AOM episodes in 124 children, 117 were analyzed (median age: 17 months (range: 3-35); eight AOM episodes were excluded from analyses. Overall, 69% (81/117) episodes were combined culture- and PCR-positive for ≥1 bacterial pathogen; 44% (52/117) and 39% (46/117) were positive for Haemophilus influenzae (Hi) and Streptococcus pneumoniae (Spn), respectively. 77 of 117 episodes were cultured for ≥1 bacteria, of which 63 were culture-positive; most commonly Spn (24/77; 31%) and Hi (32/77; 42%). PCR on culture-negative episodes identified 48% Hi- and 55% Spn-positive episodes. The most common Spn serotype was 19F (4/24; 17%) followed by 19A (3/24; 13%); all Hi-positive episodes were non-typeable (NTHi). 81/117 AOM episodes (69%) occurred in children who had received ≥1 pneumococcal vaccine dose.

CONCLUSIONS

NTHi and Spn were the main etiological agents for AOM in Spain. Impact of pneumococcal vaccination on AOM requires further evaluation in Spain, after higher vaccination coverage rate is reached.

A phase 1, open-label safety and immunogenicity study of an AS03-adjuvanted trivalent inactivated influenza vaccine in children aged 6 to 35 months

Background: There is a need for better vaccines and vaccine strategies to reduce the burden of influenza in very young children.

 

Methods: This phase 1, open-label study assessed the reactogenicity, safety, and immunogenicity of an inactivated trivalent influenza vaccine (TIV) containing low doses of hemagglutinin antigen (7.5 µg each strain), adjuvanted with a tocopherol-based oil-in-water emulsion Adjuvant System (AS03). Influenza vaccine-naïve children aged 6–35 months were sequentially enrolled to receive TIV-AS03_D (1.48 mg tocopherol) or TIV-AS03_C (2.97 mg tocopherol), then a 6-month booster of conventional TIV. The primary endpoint was the incidence of fever (axillary temperature >38 °C) for 7 days post-vaccination. Immune responses were assessed by hemagglutination-inhibition (HI) assay.

Results: Forty children were sequentially enrolled into the TIV-AS03_D or the TIV-AS03_C group. Fever >38.0 °C was reported in 5/20 (25.0%) and 7/20 (35.0%) children after the first and second doses of TIV-AS03_D, respectively, and in 7/20 (35.0%) children after 1 dose of TIV-AS03_C; the latter fulfilled the holding rule for safety, and the second dose of TIV-AS03_C was cancelled. HI immune responses exceeded adult European licensure criteria for the immunogenicity, and all children had HI antibody titers ≥ 1:40 after 1 dose of TIV booster against booster strains.

Conclusions: One dose of primary vaccine containing a low dose of antigen and AS03 may be a possible influenza vaccination strategy for young children. The relatively high frequency of fever warrants further investigation, although the generalizability of the findings are uncertain given that many of the children had antibody evidence suggesting recent infection with A(H1N1)pdm09.

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine candidate: a phase III randomized controlled trial in children

BACKGROUND

Mismatch between circulating influenza B viruses (Yamagata and Victoria lineages) and vaccine strains occurs frequently.

METHODS

In a randomized controlled trial, immunogenicity and safety of an inactivated quadrivalent influenza vaccine candidate (QIV) versus trivalent inactivated influenza vaccine (TIV)-Victoria(Vic) and TIV-Yamagata(Yam) in children 3-17 years of age was evaluated. In an open-label study arm, QIV only was assessed in children 6-35 months of age.

RESULTS

A total of 3094 children (932 QIV, 929 TIV-Vic, 932 TIV-Yam, and 301 QIV only) were vaccinated. QIV was noninferior to the TIVs for shared strains (A/H3N2 and A/H1N1) based on hemagglutination-inhibition (HI) antibodies 28 days after last vaccination, and superior for the unique B strains Victoria and Yamagata (geometric mean titer ratios 2.61, 3.78; seroconversion rate differences 33.96%, 44.63%). Among children in the randomized trial, adverse event rates were similar except for injection site pain (dose 1: 65.4% QIV, 54.6% TIV-Vic, 55.7% TIV-Yam).

CONCLUSION

QIV elicited superior HI responses to the added B strains compared to TIV controls, potentially improving its effectiveness against influenza B. HI responses were similar between QIV and TIV controls for the shared strains. QIV had an acceptable safety profile relative to TIVs.

CLINICAL TRIALS REGISTRATION

NCT01198756.