Immunogenicity, otitis media, hearing impairment, and nasopharyngeal carriage 6-months after 13-valent or ten-valent booster pneumococcal conjugate vaccines, stratified by mixed priming schedules: PREVIX_COMBO and PREVIX_BOOST randomised controlled trials

Immunogenicity and seroefficacy of pneumococcal conjugate vaccines: a systematic review and network meta-analysis

Background

Vaccination of infants with pneumococcal conjugate vaccines is recommended by the World Health Organization. Evidence is mixed regarding the differences in immunogenicity and efficacy of the different pneumococcal vaccines.

Objectives

The primary objective was to compare the immunogenicity of pneumococcal conjugate vaccine-10 versus pneumococcal conjugate vaccine-13. The main secondary objective was to compare the seroefficacy of pneumococcal conjugate vaccine-10 versus pneumococcal conjugate vaccine-13.

Methods

We searched the Cochrane Library, EMBASE, Global Health, MEDLINE, ClinicalTrials.gov and trialsearch.who.int up to July 2022. Studies were eligible if they directly compared either pneumococcal conjugate vaccine-7, pneumococcal conjugate vaccine-10 or pneumococcal conjugate vaccine-13 in randomised trials of children under 2 years of age, and provided immunogenicity data for at least one time point. Individual participant data were requested and aggregate data used otherwise. Outcomes included the geometric mean ratio of serotype-specific immunoglobulin G and the relative risk of seroinfection. Seroinfection was defined for each individual as a rise in antibody between the post-primary vaccination series time point and the booster dose, evidence of presumed subclinical infection. Each trial was analysed to obtain the log of the ratio of geometric means and its standard error. The relative risk of seroinfection ('seroefficacy') was estimated by comparing the proportion of participants with seroinfection between vaccine groups. The log-geometric mean ratios, log-relative risks and their standard errors constituted the input data for evidence synthesis. For serotypes contained in all three vaccines, evidence could be synthesised using a network meta-analysis. For other serotypes, meta-analysis was used. Results from seroefficacy analyses were incorporated into a mathematical model of pneumococcal transmission dynamics to compare the differential impact of pneumococcal conjugate vaccine-10 and pneumococcal conjugate vaccine-13 introduction on invasive pneumococcal disease cases. The model estimated the impact of vaccine introduction over a 25-year time period and an economic evaluation was conducted.

Results

In total, 47 studies were eligible from 38 countries. Twenty-eight and 12 studies with data available were included in immunogenicity and seroefficacy analyses, respectively. Geometric mean ratios comparing pneumococcal conjugate vaccine-13 versus pneumococcal conjugate vaccine-10 favoured pneumococcal conjugate vaccine-13 for serotypes 4, 9V and 23F at 1 month after primary vaccination series, with 1.14- to 1.54-fold significantly higher immunoglobulin G responses with pneumococcal conjugate vaccine-13. Risk of seroinfection prior to the time of booster dose was lower for pneumococcal conjugate vaccine-13 for serotype 4, 6B, 9V, 18C and 23F than for pneumococcal conjugate vaccine-10. Significant heterogeneity and inconsistency were present for most serotypes and for both outcomes. Twofold higher antibody after primary vaccination was associated with a 54% decrease in risk of seroinfection (relative risk 0.46, 95% confidence interval 0.23 to 0.96). In modelled scenarios, pneumococcal conjugate vaccine-13 or pneumococcal conjugate vaccine-10 introduction in 2006 resulted in a reduction in cases that was less rapid for pneumococcal conjugate vaccine-10 than for pneumococcal conjugate vaccine-13. The pneumococcal conjugate vaccine-13 programme was predicted to avoid an additional 2808 (95% confidence interval 2690 to 2925) cases of invasive pneumococcal disease compared with pneumococcal conjugate vaccine-10 introduction between 2006 and 2030.

Limitations

Analyses used data from infant vaccine studies with blood samples taken prior to a booster dose. The impact of extrapolating pre-booster efficacy to post-booster time points is unknown. Network meta-analysis models contained significant heterogeneity which may lead to bias.

Conclusions

Serotype-specific differences were found in immunogenicity and seroefficacy between pneumococcal conjugate vaccine-13 and pneumococcal conjugate vaccine-10. Higher antibody response after vaccination was associated with a lower risk of subsequent infection. These methods can be used to compare the pneumococcal conjugate vaccines and optimise vaccination strategies. For future work, seroefficacy estimates can be determined for other pneumococcal vaccines, which could contribute to licensing or policy decisions for new pneumococcal vaccines.

Study registration

This study is registered as PROSPERO CRD42019124580.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/148/03) and is published in full in Health Technology Assessment; Vol. 28, No. 34. See the NIHR Funding and Awards website for further award information.

ISOM 2023 Research Panel 5: Interventions- Vaccines and prevention, medical and surgical treatment, and impact of COVID-19 pandemic

OBJECTIVES

To identify and synthesize key research advances from the literature published between 2019 and 2023 on the advances in preventative measures, and medical and surgical treatment of uncomplicated otitis media (OM) including the impact of the COVID-19 pandemic on OM management.

DATA SOURCES

Medline (PubMed), Embase, and the Cochrane Library.

REVIEW METHODS

All relevant original articles published in English between June 2019 and February 2023 were identified. Studies related to guideline adherence, impact of treatment on immune response and/or microbiology, tympanoplasty, Eustachian tube balloon dilatation, mastoidectomy procedures, and those focusing on children with Down's syndrome or cleft palate were excluded.

MAIN FINDINGS

Of the 9280 unique records screened, 64 were eligible for inclusion; 23 studies related to medical treatment, 20 to vaccines, 13 to surgical treatment, 6 to prevention (excl. vaccines) and 2 to the impact of COVID-19 on OM management. The level of evidence was judged 2 in 11 studies (17.2 %) and 3 or 4 in the remaining 53 studies (82.8 %) mainly due to the observational design, study limitations or low sample sizes. Some important advances in OM management have been made in recent years. Video discharge instructions detailing the identification and management of pain and fever for parents of children with acute otitis media (AOM) was more effective than paper instructions in reducing symptomatology; compared to placebo, levofloxacin solution was more effective for treating chronic suppurative otitis media, whereas AOM recurrences during two years of follow-up did not differ between children with recurrent AOM who received tympanostomy tube (TT) insertion or medical management. Further, novel pneumococcal conjugate vaccines (PCV) schedules for preventing OM in Aboriginal children appeared ineffective, and a protein-based pneumococcal vaccine had no added value over PCV13 for preventing AOM in native American infants. During the COVID-19 pandemic, a decline in OM and TT case volumes and complications was observed.

IMPLICATION FOR PRACTICE AND FUTURE RESEARCH

Whether the observed impact of the COVID-19 pandemic on OM management extends to the post-pandemic era is uncertain. Furthermore, the impact of the pandemic on the conduct of urgently needed prospective methodologically rigorous interventional studies aimed at improving OM prevention and treatment remains to be elucidated since the current report consisted of studies predominantly conducted in the pre-pandemic era.

Otitis media at 6-monthly assessments of Australian First Nations children between ages 12-36 months: Findings from two randomised controlled trials of combined pneumococcal conjugate vaccines

OBJECTIVES

In remote communities of northern Australia, First Nations children with hearing loss are disproportionately at risk of poor school readiness and performance compared to their peers with no hearing loss. The aim of this trial is to prevent early childhood persisting otitis media (OM), associated hearing loss and developmental delay. To achieve this, we designed a mixed pneumococcal conjugate vaccine (PCV) schedule that could maximise immunogenicity and thereby prevent bacterial otitis media (OM) and a trajectory of educational and social disadvantage.

METHODS

In two sequential parallel, open-label, randomised controlled trials, eligible infants were first allocated 1:1:1 to standard or mixed PCV primary schedules at age 28-38 days, then at age 12 months to a booster dose (1:1) of 13-valent PCV, PCV13 (Prevenar13®, +P), or 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugated vaccine, PHiD-CV10 (Synflorix®, +S). Here we report findings of standardised ear assessments conducted six-monthly from age 12-36 months, by booster dose.

RESULTS

From March 2013 to September 2018, 261 children were allocated to booster + P (n = 131) or + S (n = 130). There were no significant differences in prevalence of any OM diagnosis by booster dose or when stratified by primary schedule. We found high, almost identical prevalence of OM in both boost groups at each age (for example 88% of 129 and 91% of 128 children seen, respectively, at primary endpoint age 18 months, difference -3% [95% Confidence Interval -11, 5]). At each age prevalence of bilateral OM was 52%-78%, and tympanic membrane perforation was 10%-18%.

CONCLUSION

Despite optimal pneumococcal immunisation, the high prevalence of OM persists throughout early childhood. Novel approaches to OM prevention are needed, along with improved early identification strategies and evaluation of expanded valency PCVs.

Trajectories of otitis media and association with health determinants among Indigenous children in Australia: the Longitudinal Study of Indigenous Children

OBJECTIVES

Indigenous children in Australia experience high burden of persistent otitis media (OM) from very early age. The aim was to identify distinct trajectories of OM in children up to age 10-12 years and examine the association with socio-economic determinants.

STUDY DESIGN

A multistage clustered national panel survey.

METHODS

The study analysed the birth cohort of the Longitudinal Study of Indigenous Children from 2008 to 2018, comprising 11 study waves. Group-based trajectory modelling was used to identify different trajectories of OM outcome. Multinomial logistic regression was applied to examine the relationship between trajectories and individual, household and community-level socio-economic determinants.

RESULTS

This analysis included 894 children with at least three responses on OM over the 11 waves, and the baseline mean age was 15.8 months. Three different trajectories of OM were identified: non-severe OM prone, early/persistent severe OM and late-onset severe OM. Overall, 11.4% of the children had early/persistent severe OM from birth to 7.5 to nine years, while late-onset severe OM consisted of 9.8% of the children who had first OM from age 3.5 to five years. Children in communities with middle and the highest socio-economic outcomes have lower relative risk of early/persistent severe OM (adjusted relative risk ratio = 0.39, 95% confidence interval = 0.22-0.70 and adjusted relative risk ratio = 0.22, 95% confidence interval = 0.09-0.52, respectively) compared to children in communities with lowest socio-economic outcomes.

CONCLUSION

Efforts to close the gap in the quality of life of Indigenous children must prioritise strategies that prevent severe ear disease (runny ears and perforation), including improved healthcare access, reduced household crowding, and better education, and more employment opportunities.

An evaluation of the quality of ear health services for Aboriginal children living in remote Australia: a cascade of care analysis

BACKGROUND

In the Northern Territory (NT) the prevalence of otitis media (OM) in young Aboriginal children living in remote communities has persisted at around 90% over the last few decades. OM-associated hearing loss can cause developmental delay and adversely impact life course trajectories. This study examined the 5-year trends in OM prevalence and quality of ear health services in remote NT communities.

METHODS

A retrospective analysis was performed on de-identified clinical data for 50 remote clinics managed by the NT Government. We report a 6-monthly cascade analysis of the proportions of children 0-16 years of age receiving local guideline recommendations for surveillance, OM treatment and follow-up at selected milestones between 2014 and 2018.

RESULTS

Between 6,326 and 6,557 individual children were included in the 6-monthly analyses. On average, 57% (95%CI: 56-59%) of eligible children had received one or more ear examination in each 6-monthly period. Of those examined, 36% (95%CI: 33-40%) were diagnosed with some type of OM, of whom 90% had OM requiring either immediate treatment or scheduled follow-up according to local guidelines. Outcomes of treatment and follow-up were recorded in 24% and 23% of cases, respectively. Significant decreasing temporal trends were found in the proportion diagnosed with any OM across each age group. Overall, this proportion decreased by 40% over the five years (from 43 to 26%).

CONCLUSIONS

This cascade of care analysis found that ear health surveillance and compliance with otitis media guidelines for treatment and follow-up were both low. Further research is required to identify effective strategies that improve ear health services in remote settings.

Randomised controlled trial of perinatal vitamin D supplementation to prevent early-onset acute respiratory infections among Australian First Nations children: the 'D-Kids' study protocol

INTRODUCTION

Globally, acute respiratory infections (ARIs) are a leading cause of childhood morbidity and mortality. While ARI-related mortality is low in Australia, First Nations infants are hospitalised with ARIs up to nine times more often than their non-First Nations counterparts. The gap is widest in the Northern Territory (NT) where rates of both acute and chronic respiratory infection are among the highest reported in the world. Vitamin D deficiency is common among NT First Nations neonates and associated with an increased risk of ARI hospitalisation. We hypothesise that perinatal vitamin D supplementation will reduce the risk of ARI in the first year of life.

METHODS AND ANALYSIS

'D-Kids' is a parallel (1:1), double-blind (allocation concealed), randomised placebo-controlled trial conducted among NT First Nations mother-infant pairs. Pregnant women and their babies (n=314) receive either vitamin D or placebo. Women receive 14 000 IU/week or placebo from 28 to 34 weeks gestation until birth and babies receive 4200 IU/week or placebo from birth until age 4 months. The primary outcome is the incidence of ARI episodes receiving medical attention in the first year of life. Secondary outcomes include circulating vitamin D level and nasal pathogen prevalence. Tertiary outcomes include infant immune cell phenotypes and challenge responses. Blood, nasal swabs, breast milk and saliva are collected longitudinally across four study visits: enrolment, birth, infant age 4 and 12 months. The sample size provides 90% power to detect a 27.5% relative reduction in new ARI episodes between groups.

ETHICS AND DISSEMINATION

This trial is approved by the NT Human Research Ethics Committee (2018-3160). Study outcomes will be disseminated to participant families, communities, local policy-makers, the broader research and clinical community via written and oral reports, education workshops, peer-reviewed journals, national and international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12618001174279.

Efficacy against pneumococcal carriage and the immunogenicity of reduced-dose (0 + 1 and 1 + 1) PCV10 and PCV13 schedules in Ho Chi Minh City, Viet Nam: a parallel, single-blind, randomised controlled trial

BACKGROUND

Interest in reduced-dose pneumococcal conjugate vaccine (PCV) schedules is growing, but data on their ability to provide direct and indirect protection are scarce. We evaluated 1 + 1 (at 2 months and 12 months) and 0 + 1 (at 12 months) schedules of PCV10 or PCV13 in a predominately unvaccinated population.

METHODS

In this parallel, single-blind, randomised controlled trial, healthy infants aged 2 months were recruited from birth records in three districts in Ho Chi Minh City, Vietnam, and assigned (4:4:4:4:9) to one of five groups: PCV10 at 12 months of age (0 + 1 PCV10), PCV13 at 12 months of age (0 + 1 PCV13), PCV10 at 2 months and 12 months of age (1 + 1 PCV10), PCV13 at 2 months and 12 months of age (1 + 1 PCV13), and unvaccinated control. Outcome assessors were masked to group allocation, and the infants' caregivers and those administering vaccines were not. Nasopharyngeal swabs collected at 6 months, 12 months, 18 months, and 24 months were analysed for pneumococcal carriage. Blood samples collected from a subset of participants (200 per group) at various timepoints were analysed by ELISA and opsonophagocytic assay. The primary outcome was the efficacy of each schedule against vaccine-type carriage at 24 months, analysed by intention to treat for all those with a nasopharyngeal swab available. This trial is registered at ClinicalTrials.gov, NCT03098628.

FINDINGS

2501 infants were enrolled between March 8, 2017, and July 24, 2018 and randomly assigned to study groups (400 to 0 + 1 PCV10, 400 to 0 + 1 PCV13, 402 to 1 + 1 PCV10, 401 to 1 + 1 PCV13, and 898 to control). Analysis of the primary endpoint included 341 participants for 0 + 1 PCV10, 356 0 + 1 PCV13, 358 1 + 1 PCV10, 350 1 + 1 PCV13, and 758 control. At 24 months, a 1 + 1 PCV10 schedule reduced PCV10-type carriage by 58% (95% CI 25 to 77), a 1 + 1 PCV13 schedule reduced PCV13-type carriage by 65% (42 to 79), a 0 + 1 PCV10 schedule reduced PCV10-type carriage by 53% (17 to 73), and a 0 + 1 PCV13 schedule non-significantly reduced PCV13-type carriage by 25% (-7 to 48) compared with the unvaccinated control group. Reactogenicity and serious adverse events were similar across groups.

INTERPRETATION

A 1 + 1 PCV schedule greatly reduces vaccine-type carriage and is likely to generate substantial herd protection and provide some degree of individual protection during the first year of life. Such a schedule is suitable for mature PCV programmes or for introduction in conjunction with a comprehensive catch-up campaign, and potentially could be most effective given as a mixed regimen (PCV10 then PCV13). A 0 + 1 PCV schedule has some effect on carriage along with a reasonable immune response and could be considered for use in humanitarian crises or remote settings.

FUNDING

Bill & Melinda Gates Foundation.

TRANSLATION

For the Vietnamese translation of the abstract see Supplementary Materials section.

What does microbiology have to do with the Hearing for Learning Initiative (HfLI)?

Where would we be without microbiology in tackling the high prevalence of otitis media (OM; middle ear infection) and disabling hearing loss that disadvantage Australian First Nations children living in remote communities? Understanding the microbiology of OM in this population has been critical in directing innovative clinical trials research and developing appropriate evidence-based practice guidelines. While these processes are critical to reducing disadvantage associated with OM and disabling hearing loss, a remaining seemingly insurmountable gap has remained, threatening progress in improving the lives of children with ear and hearing problems. That gap is created by the crisis in primary health care workforce in remote communities. Short stay health professionals and fly-in fly-out specialist services are under-resourced to manage the complex needs of the community, including prevention and treatment of otitis media and hearing loss rehabilitation. Hence the rationale for the Hearing for Learning Initiative – a workforce enhancement model to improve sustainability, cultural appropriateness, and effectiveness of evidence-based ear and hearing health care for young children in remote settings. This paper summarises the role of microbiology in the pathway to the Hearing for Learning Initiative.