Effectiveness and impact of the 10-valent pneumococcal conjugate vaccine, PHiD-CV: review of clinical trials and post-marketing experience

Invasive pneumococcal disease among the elderly in the later era of paediatric pneumococcal conjugate vaccination-A longitudinal study over 10 years based on public surveillance data in the Nordics

BACKGROUND

Pneumococcal conjugate vaccines (PCVs) have proven effective in preventing both non-invasive and invasive pneumococcal disease (IPD) in small children and in older age groups. However, long-term observations and country comparisons of IPD incidence in the elderly following introduction of PCVs in paediatric national immunisation programmes (NIPs) are scarce. We aimed to estimate and compare incidence of IPD in the elderly in Denmark, Finland, Norway, and Sweden over a 10-year time span. During the study period Denmark and Norway used PCV13 in their paediatric NIP, Sweden both PCV10 and PCV13 and Finland used PCV10. Uptake of pneumococcal vaccines for the elderly was low.

METHOD

We collected longitudinal data on confirmed IPD cases and their serotypes among elderly people (aged ≥65 years) 2010-2019 in the four countries of interest. Annual IPD incidence rates were calculated per country, by vaccine-associated serotypes (PCV10, PCV13, PCV15, PCV20 and PPV23) and for non-vaccine serotypes. A regression model was used to estimate average annual change in incidence in each country.

RESULTS

Incidence rates of IPD in the elderly in 2019 ranged from 31.4 to 41.8 per 100,000 people across the countries. Denmark and Norway showed an annual average decline in IPD incidence (-3.3; 95% CI: -5.6 to -1.1; p<0.01) and (-3.3; 95% CI: -5.5 to -1.0; p<0.01) respectively from 2010 to 2019, whereas no change was seen for Sweden (-0.5; 95% CI: -1.9 to 0.8; p = 0.39) or Finland (0.9; 95% CI: -1.0 to 2.7; p = 0.32). IPD incidence due to emerging serotypes, e.g., serotypes 8 and 12F, has increased. Serotype 19A remained a major cause of IPD in countries with PCV10 in paediatric NIPs.

CONCLUSION

Despite paediatric PCV programmes, a considerable vaccine preventable IPD burden remains in the elderly. Further, choice of PCV in paediatric programs was associated with differences in serotype distribution and incidence amongst the elderly. Direct vaccination of the elderly with recently approved broad coverage PCVs holds promise for meaningful impact on disease burden with PCV20 covering a majority of IPD amongst the elderly in the four studied countries. Effectiveness of new vaccines in real-life clinical practice should be followed.

Effect of reduced two-dose (1+1) schedule of 10 and 13-valent pneumococcal conjugate vaccines (SynflorixTM and Prevenar13TM)) on nasopharyngeal carriage and serotype-specific immune response in the first two years of life: Results from an open-labelled randomized controlled trial in Indian children

INTRODUCTION

This study aimed to assess the effect of a reduced dose regime (1 + 1) of PCV10 and PCV13 along with 3-dose regimes on pneumococcal vaccine-type (VT) carriage and immunogenicity in the first two years of life in PCV-naïve Indian children.

METHODS

A total of 805 healthy infants aged 6-8 weeks were randomised to 7 groups (n = 115). Six groups received Synflorix^TM(PCV10) or Prevenar13^TM(PCV13) in the following schedules: 3 + 0 (three primary at 6, 10, and 14 weeks); 2 + 1 (two primary 6 and 14 weeks with booster at 9 months; 1 + 1 (one primary at 14 weeks with booster at 9 months). The 7th group was a PCV-naïve control group. Nasopharyngeal swabs were collected at 6, 18 weeks, 9, 10, 15, and 18 months of age. Venous blood samples were collected at 18 weeks, 9, 10, and 18 months of age for assessment of sero-specific IgG antibodies. Additionally, functional activity using a serotype specific opsonophagocytic assay (OPA) was assessed at 10 and 18 months of age in a subset (20%) of participants.

RESULTS

All schedules of PCV13 showed significant 13VT carriage reduction in the second year of life as compared to control. At 15 months of age, PCV13 (1 + 1) showed 45 % reduction in 13VT-carriage compared to the control [OR = 0.55 (95% CI; 0.31-0.97), p= 0.038]. None of the PCV10 schedules showed significant reduction in 10VT carriage in the second year. Although not powered for these outcomes, at 18 months of age, 1 + 1 and 2 + 1 schedules of both vaccines demonstrated higher sero-responders for all serotypes, higher geometric mean concentrations (GMC) for all serotypes except 23F [with both vaccines], higher percent OPA responders and OPA geometric mean titres (GMT) compared to the 3 + 0 schedules for all serotypes.

CONCLUSION

The reduced dose schedule (1 + 1) of PCV13 results in significant VT-carriage reduction in the second year of life. Immune protection provided by 1 + 1 schedules of PCV10 and PCV13 in the second year of life is comparable to WHO-recommended 3-dose schedules.

A systematic review of invasive pneumococcal disease vaccine failures and breakthrough with higher-valency pneumococcal conjugate vaccines in children

INTRODUCTION

: The pneumococcal non-typeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV or PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) protect against vaccine-serotype invasive pneumococcal disease (VT IPD). However, VT IPD can still occur in fully or partially vaccinated children (vaccine failure or breakthrough). We performed a systematic review of vaccine failures and breakthrough IPD with PCV10 and PCV13 in ≤5-year-olds.

AREAS COVERED

: We searched Scopus/Medline/EMBASE to retrieve articles/abstracts published between 1/2008-7/2019. We excluded reports from studies only including data from adults or children ≥6 years, exclusively assessing PCV7-vaccinated children or children with underlying comorbidities. Twenty-six reports (20 PCV13, 1 PCV10, 5 both), covering studies with various designs in six continents, using different schedules, were included. Collectively, these studies reported 469 VT IPD cases classified as vaccine failures and 403 as breakthrough. Vaccine failure and breakthrough rates were low: 8.4% and 9.3%, respectively, of all IPD in vaccinated children, consistent with the vaccines' high effectiveness. The main serotypes associated with vaccine failure or breakthrough were 19A, 3 and 19F in PCV13 studies and 14, 6B and vaccine-related 19A and 6A in PCV10 studies.

EXPERT OPINION

: As we move to vaccines with more serotypes, it is not only important to consider which serotypes are added, but also to monitor and address incomplete protection against specific serotypes.

Informing decision makers seeking to improve vaccination programs: case-study Serbia

Background:The optimisation of vaccine policies before their implementation is beholden upon public health decision makers, seeking to maximise population health. In this case study in Serbia, the childhood vaccines under consideration included pneumococcal conjugate vaccination (PCV), rotavirus (RV) vaccination and varicella zoster virus (VZV) vaccination. Objective: The objective of this study is to define the optimal order of introduction of vaccines to minimise deaths, quality adjusted life years (QALYs) lost, or hospitalisation days, under budget and vaccine coverage constraints. Methods: A constrained optimisation model was developed including a static multi-cohort decision-tree model for the three infectious diseases. Budget and vaccine coverage were constrained, and to rank the vaccines, the optimal solution to the linear programming problem was based upon the ratio of the outcome (deaths, QALYs or hospitalisation days) per unit of budget. A probabilistic decision analysis Monte Carlo simulation technique was used to test the robustness of the rankings. Results: PCV was the vaccine ranked first to minimise deaths, VZV vaccination for QALY loss minimisation and RV vaccination for hospitalisation day reduction. Sensitivity analysis demonstrated the most robust ranking was that for PCV minimizing deaths. Conclusion: Constrained optimisation modelling, whilst considering all potential interventions currently, provided a comprehensive and rational approach to decision making.

Long-term population effects of infant 10-valent pneumococcal conjugate vaccination on pneumococcal meningitis in Finland

BACKGROUND

No previous studies have reported long-term follow-up of ten-valent pneumococcal conjugate vaccine (PCV10) program impact on pneumococcal meningitis (PM). We assessed the effects of infant PCV10 program on PM incidence, mortality and serotype distribution in children and adults during 7 years after introduction.

METHODS

We conducted a population-based observational study. A case of PM was defined as isolation of Streptococcus pneumoniae from cerebrospinal fluid or, a patient with S. pneumoniae isolated from blood and an ICD-10 hospital discharge diagnosis of bacterial meningitis within 30 days before or after positive culture date.We compared age- and serotype-specific incidence and associated 30-day mortality rates in 2011-2017 (PCV10 period) with those in 2004-2010 (pre-PCV10 baseline) by using Poisson regression models. Absolute rate differences and 95% confidence intervals (CIs) were calculated from the parameter estimates by using delta method.

RESULTS

During the PCV10 period, the overall incidence of PCV10 serotype meningitis decreased by 68% (95%CI 57%-77%), and the overall PM incidence by 27% (95%CI: 12%-39%). In age groups 0-4, 50-64, and ≥ 18 years, the overall PM incidence was reduced by 64%, 34% and 19%, respectively. In adults ≥ 65 years of age, a 69% reduction in PCV10 serotypes was offset by 157% (56%-342%) increase in non-PCV10 serotypes. The overall PM-related mortality rate decreased by 42% (95%CI 4%-65%). Overall case fatality proportion (CFP) was 16% in pre-PCV10 period and 12% in PCV10 period (p = 0.41); among persons 50-64 years the CFP decreased from 25% to 10% (p = 0.04).

CONCLUSIONS

We observed substantial impact and herd protection for vaccine-serotype PM and associated mortality after infant PCV10 introduction. However, in older adults ≥ 65 years of age, PM burden remains unchanged due to serotype replacement.

Pneumococcal Disease Prevention: Are We on the Right Track?

The history of Streptococcus pneumoniae diseases dramatically changed with the introduction into the immunization schedule of infants and children of the first pneumococcal conjugate vaccine, the one containing 7 (PCV7) of the most common pneumococcal serotypes (STs) causing invasive pneumococcal diseases (IPDs). Where PCV7 was largely used, incidence of both IPDs and non-invasive pneumococcal diseases (nIPDs) in vaccinated children and in unvaccinated subjects of any age, mainly the elderly, significantly decreased. Unfortunately, the impact of PCV7 administration was slightly lower than expected, as the reduction in infections due to vaccine serotypes (STs) was accompanied by a significant increase in the number of IPDs and nIPDs due to STs not included in the vaccine. To overcome this problem, two PCVs containing 10 (PCV10) and 13 (PCV13) STs, chosen among those emerging, were developed and licensed. However, ST replacement occurred again. Moreover, the new PCVs showed little effectiveness in the prevention of infection due to non-encapsulated STs and to ST3. Next-generation S. pneumoniae vaccines able to prevent pneumococcal infections regardless of infecting ST are urgently needed. For the moment, the use of available PCVs remains fundamental because their benefits far outweigh any concerns for emerging STs.

Impact of Switch Options on the Economics of Pneumococcal Conjugate Vaccine (PCV) Introduction in Indonesia

As one of Gavi, the Vaccine Alliance (previously the Global Alliance for Vaccines and Immunization), graduating countries, Indonesia is still eligible to access Gavi price for PCV13, PCV10 A and B. This study aims to estimate the economic impact of switch from the existing product/presentation of PCV (single-dose of PCV13) to the new product/presentation of PCV (multi-dose of PCV13, PCV10 A and B) since PCV is one of the most expensive vaccines in the Expanded Program on Immunization (EPI) schedule. Assuming that Gavi-Advance Market Commitment (AMC) price for all PCVs can be accessed in 2021, the use of multi-dose PCV13, PCV10 A and PCV10 B with Gavi-AMC price in 2021–2024 were considered as respective scenarios. The result showed that the scenario assuming the use of single-dose of PCV13 with contract price in 2019–2020 that would be switched into multi-dose of PCV10 B with Gavi-AMC price in 2021–2024 resulted in the highest potential saving, compared with other scenarios. Our analysis suggests an economic advantage to switch from single-dose into a multi-dose presentation. Vaccination coverage, vaccine price, vaccine wastage and additional Gavi-AMC vaccine costs were considered to be the most influential parameter affecting the savings in all scenarios. Applying the effectiveness of PCV13 and PCV10 A on reducing the risk for invasive pneumococcal disease (IPD), potential averted incidence of IPD in children under one year of age during 2019–2024 would be 246,164 and 105,587 in both scenarios. Despite the result confirmed that PCV13 may provide an additional benefit, a more comprehensive economic evaluation study is required to investigate further the comparison of cost-effectiveness values among all PCVs in Indonesia.

Development of Next Generation Streptococcus pneumoniae Vaccines Conferring Broad Protection

Streptococcus pneumoniae is a major pathogen causing pneumonia with over 2 million deaths annually, especially in young children and the elderly. To date, at least 98 different pneumococcal capsular serotypes have been identified. Currently, the vaccines for prevention of S. pneumoniae infections are the 23-valent pneumococcal polysaccharide-based vaccine (PPV23) and the pneumococcal conjugate vaccines (PCV10 and PCV13). These vaccines only cover some pneumococcal serotypes and are unable to protect against non-vaccine serotypes and unencapsulated S. pneumoniae. This has led to a rapid increase in antibiotic-resistant non-vaccine serotypes. Hence, there is an urgent need to develop new, effective, and affordable pneumococcal vaccines, which could cover a wide range of serotypes. This review discusses the new approaches to develop effective vaccines with broad serotype coverage as well as recent development of promising pneumococcal vaccines in clinical trials. New vaccine candidates are the inactivated whole-cell vaccine strain (Δpep27ΔcomD mutant) constructed by mutations of specific genes and several protein-based S. pneumoniae vaccines using conserved pneumococcal antigens, such as lipoprotein and surface-exposed protein (PspA). Among the vaccines in Phase 3 clinical trials are the pneumococcal conjugate vaccines, PCV-15 (V114) and 20vPnC. The inactivated whole-cell and several protein-based vaccines are either in Phase 1 or 2 trials. Furthermore, the recent progress of nanoparticles that play important roles as delivery systems and adjuvants to improve the performance, as well as the immunogenicity of the nanovaccines, are reviewed.

Panel 3: Genomics, precision medicine and targeted therapies

OBJECTIVE

To review the most recent advances in human and bacterial genomics as applied to pathogenesis and clinical management of otitis media.

DATA SOURCES

PubMed articles published since the last meeting in June 2015 up to June 2019.

REVIEW METHODS

A panel of experts in human and bacterial genomics of otitis media was formed. Each panel member reviewed the literature in their respective fields and wrote draft reviews. The reviews were shared with all panel members, and a merged draft was created. The panel met at the 20th International Symposium on Recent Advances in Otitis Media in June 2019, discussed the review and refined the content. A final draft was made, circulated, and approved by the panel members.

CONCLUSION

Trans-disciplinary approaches applying pan-omic technologies to identify human susceptibility to otitis media and to understand microbial population dynamics, patho-adaptation and virulence mechanisms are crucial to the development of novel, personalized therapeutics and prevention strategies for otitis media.

IMPLICATIONS FOR PRACTICE

In the future otitis media prevention strategies may be augmented by mucosal immunization, combination vaccines targeting multiple pathogens, and modulation of the middle ear microbiome. Both treatment and vaccination may be tailored to an individual's otitis media phenotype as defined by molecular profiles obtained by using rapidly developing techniques in microbial and host genomics.

Designing ecologically optimized pneumococcal vaccines using population genomics

Streptococcus pneumoniae (the pneumococcus) is a common nasopharyngeal commensal that can cause invasive pneumococcal disease (IPD). Each component of current protein-polysaccharide conjugate vaccines (PCVs) generally induces immunity specific to one of the approximately 100 pneumococcal serotypes, and typically eliminates it from carriage and IPD through herd immunity. Overall carriage rates remain stable owing to replacement by non-PCV serotypes. Consequently, the net change in IPD incidence is determined by the relative invasiveness of the pre- and post-PCV-carried pneumococcal populations. In the present study, we identified PCVs expected to minimize the post-vaccine IPD burden by applying Bayesian optimization to an ecological model of serotype replacement that integrated epidemiological and genomic data. We compared optimal formulations for reducing infant-only or population-wide IPD, and identified potential benefits to including non-conserved pneumococcal carrier proteins. Vaccines were also devised to minimize IPD resistant to antibiotic treatment, despite the ecological model assuming that resistance levels in the carried population would be preserved. We found that expanding infant-administered PCV valency is likely to result in diminishing returns, and that complementary pairs of infant- and adult-administered vaccines could be a superior strategy. PCV performance was highly dependent on the circulating pneumococcal population, further highlighting the advantages of a diversity of anti-pneumococcal vaccination strategies.

Interchangeability between pneumococcal conjugate vaccines for pediatric use: a systematic literature review

Introduction: Evidence on the interchangeability between the two pediatric pneumococcal conjugate vaccines (PCVs) - pneumococcal non-typeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) and 13-valent PCV (PCV13) - is limited but growing. We performed a systematic literature review to summarize evidence for PHiD-CV/PCV13 interchangeability regarding immunogenicity, safety, and effectiveness against pneumococcal disease. Areas covered: Seven records disclosing results from six studies on PHiD-CV/PCV13 interchangeability were identified. Four clinical trials showed that mixed schedules with a PHiD-CV-to-PCV13 switch at boosting or a PCV13-to-PHiD-CV switch during priming or at boosting were immunogenic with no apparent safety concerns. Two observational studies in the context of a programmatic PHiD-CV-to-PCV13 switch showed similarly high effectiveness against overall invasive pneumococcal disease with a mixed PHiD-CV/PCV13 schedule and a PCV13-only schedule. No effectiveness data for a PCV13-to-PHiD-CV switch and no immunogenicity/safety/effectiveness data for a PHiD-CV-to-PCV13 switch during priming were found. Expert opinion: For epidemiological or programmatic reasons, several local/national authorities have switched PCVs in their immunization programs. Consequently, children have received mixed schedules. Although herd immunity may obscure the individual effect, the limited data are reassuring. Additional evidence from these settings - especially effectiveness or impact data - may provide the necessary information for authorities to make informed decisions on interchanging PCVs.

Vaccination against Paediatric Respiratory Pathogens

Acute respiratory infections (ARIs) are extremely common in children, especially those under 5 years old. They can lead to complications, super-infection, respiratory failure, and even compromised respiratory function in adulthood. For some of the responsible pathogens, vaccines are available. This review reports current issues about vaccines against the main respiratory pathogens to highlight the available strategies to reduce the burden of paediatric respiratory disease. The optimal use of influenza, pneumococcal, pertussis and measles vaccines is required in order to reduce ARI burden. Vaccination coverage rates must be improved to achieve the full benefits of these vaccines. Recently, advances in the knowledge of respiratory syncytial virus structural biology and immunology as well as the development of new techniques to generate vaccine candidates have increased the number of promising vaccines even against this harmful pathogen.

Immunogenicity of the pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) administered concomitantly with the meningococcal serogroup B (4CMenB) vaccine in infants: A post-hoc analysis in a phase 3b, randomised, controlled trial

BACKGROUND

No data are currently available on immunogenicity of higher-valent pneumococcal conjugate vaccines when co-administered with a 4-component meningococcal serogroup B vaccine (4CMenB).

METHODS

Post-hoc analysis of pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) immunogenicity when co-administered with 4CMenB (2 + 1 schedule) and/or a CRM-conjugated meningococcal serogroup C vaccine (MenC-CRM) in a trial assessing 4CMenB reduced schedules and co-administration with MenC-CRM (NCT01339923). Infants were randomized to receive 4CMenB and MenC-CRM (Group 1) or MenC-CRM (Group 2) at 3, 5, and 12 months (M) of age. Both groups received PHiD-CV (3 + 1 schedule) as part of the Brazilian national immunisation programme at 3 M, 5 M, 7 M, and 12 M of age. Antibody responses were assessed pre-vaccination, 1 M post-dose 2, pre-booster, and 1 M post-booster.

RESULTS

Anti-pneumococcal antibody responses were in similar ranges in the two study groups.

CONCLUSIONS

4CMenB co-administration did not seem to impact antibody responses to PHiD-CV in infants.

Safety and immunogenicity of pneumococcal conjugate vaccines in preterm infants

INTRODUCTION

The introduction of pneumococcal conjugate vaccines (PCVs) in the routine immunization program has resulted in a significant decline in invasive pneumococcal diseases (IPD) around the world. Preterm infants are a special group at a high risk of invasive infection by encapsulated bacteria. However, their slow growth accrual and prolonged hospital stay frequently lead to delays in immunization, which contributes to their risk for severe infections. Areas covered: Authors reviewed the published immunogenicity and safety of the use of PCVs in preterm infants. Expert opinion: PCVs are safe and effective for use in low birth weight and in-hospital preterm infants. Local and systemic reactions are similar for both term and preterm populations. Reports were inconsistent on the risk of apnea, therefore hospitalized extremely premature infants should be kept under observation for at least 48 h after immunization.