Ten year public health impact of 13-valent pneumococcal conjugate vaccination in infants: A modelling analysis

A phase 3 study of 20-valent pneumococcal conjugate vaccine in healthy toddlers previously vaccinated in infancy with 13-valent pneumococcal conjugate vaccine

This phase 3, randomized, partially double-blind study investigated the safety, tolerability, and immunogenicity of 20-valent pneumococcal conjugate vaccine (PCV20) in healthy toddlers ≥12-<24 months of age who had previously received 2 infant doses of 13-valent PCV (PCV13). Participants were randomized to receive 1 or 2 doses of PCV20 (the second dose was administered 56-70 days after the first dose), or 1 dose of PCV13. The primary pneumococcal immunogenicity endpoint was the percentages of participants with predefined serotype-specific immunoglobulin G (IgG) concentrations (≥0.35 μg/mL) for the 7 additional serotypes 1 month after the last vaccination. Percentages of participants with predefined IgG concentrations for the 13 matched serotypes, IgG geometric mean concentrations, and opsonophagocytic activity (OPA) geometric mean titers were also evaluated for all 20 vaccine serotypes. Safety endpoints included local reactions, systemic events, adverse events, and serious adverse events. Overall, 356 participants were randomized (2-dose PCV20, n = 121; 1-dose PCV20, n = 118; PCV13, n = 117). One month after 1 PCV20 dose, ≥75.9 % of participants had IgG concentrations ≥0.35 μg/mL for all 7 additional serotypes, except serotype 12F (54.6 %). After 2 PCV20 doses, the percentage of participants with IgG concentrations ≥0.35 μg/mL for the 7 additional serotypes was ≥91.2 %. PCV20 elicited IgG and OPA responses for all 20 serotypes including serotype 12F. IgG distributions were well differentiated and substantially higher in PCV20 groups than the PCV13 group for the 7 additional serotypes, and generally similar between all groups for the 13 matched serotypes. In conclusion, a single toddler dose of PCV20 after 2 infant PCV13 doses elicited immune responses expected to help provide protection against the 7 additional serotypes and to provide similar protection against the 13 matched serotypes as PCV13. These data support a transition from PCV13 to PCV20 at the toddler dose. The safety and tolerability profile of PCV20 was similar to PCV13. Trial registration:Clinicaltrials.gov, NCT05408429.

Risk of invasive pneumococcal disease during pregnancy and postpartum and association with adverse maternal and foetal outcomes: A prospective cohort study, England, 2014-19

BACKGROUND

Pneumococcal infections are associated with significant morbidity and mortality, especially at the extremes of age and in those with underlying conditions. Little is known about the risks, presentations or outcomes of invasive pneumococcal disease (IPD) during pregnancy or the postpartum period.

METHODS

The UK Health Security Agency conducts enhanced national surveillance of IPD in England. We used national surveillance data to calculate IPD risk and outcomes in pregnant, postpartum and non-pregnant women of childbearing age with IPD over a five-year period in England.

FINDINGS

There were 1701 IPD cases in women aged 15-44 years between 1 July 2014 and 30 June 2019, including 123 (7.2%) pregnant, 38 (2.2%) postpartum and 1540 (90.5%) non-pregnant women. IPD incidence in pregnant women (0.048/1000 woman-years) was not significantly different compared to non-pregnant women (0.041/1000 woman-years; Incidence Rate Ratio [IRR]: 1.17; 95%CI 0.96-1.40; p=0.11). When stratified by trimester, however, women in their third trimester had a 2.27-fold (95%CI 1.80-2.85, p<0.001) increased risk of IPD, compared to non-pregnant women (IRR 2.27, 95%CI 1.78-2.85, p<0.001), while those in the first (IRR 0.49, 95%CI 0.28-0.80) and second trimester (IRR 0.71, 95%CI 0.47-1.04) had a lower risk, albeit only statistically significant for the first trimester. Postpartum women (0.144 per 1000 woman-years), on the other hand, had a 3.49-fold (95%CI 2.46-4.81, p<0.001) higher IPD risk than non-pregnant women. Most pregnant women developed IPD during their third trimester (80/123, 65.0%), with all but one pregnancy resulting in a live birth. IPD in the second trimester was associated with live birth in 77.8% of cases (21/27), while 22.2% experienced a miscarriage (5/27, 18.5%) or stillbirth (1/27, 3.7%). IPD in the first trimester was associated with live birth in 41.7% of cases (5/12), miscarriages in 41.7% (5/12), and termination in 16.7% (2/12) cases. Only three neonates (3/142) had confirmed IPD. There were no deaths in pregnant women with IPD compared to 5.5% (85/1540) in non-pregnant women.

INTERPRETATION

While pregnant women overall did not appear to have an increased risk of IPD compared to non-pregnant women, those infected in third trimester or postpartum appeared to have more than twice the incidence. Most pregnant and postpartum women had a live birth, and subsequent neonatal infection was rare, occurring in 2% of live births.

Safety of a 4-Dose 20-Valent Pneumococcal Conjugate Vaccine Series in Infants: A Randomized Trial

BACKGROUND AND OBJECTIVES

The 20-valent pneumococcal conjugate vaccine (PCV20) was developed to expand protection for pneumococcal disease. It contains all 13-valent pneumococcal conjugate vaccine (PCV13) components plus conjugates for 7 additional serotypes. Our primary objective with this study was to evaluate PCV20 tolerability and safety.

METHODS

In this phase 3, multi-country, double-blind study, healthy infants born at ≥34 weeks' gestation were randomly assigned 2:1 to receive PCV20 or PCV13 at 2, 4, 6, and 12 to 15 months of age. Safety assessments included local reactions and systemic events within 7 days after each vaccination, adverse events (AEs) from dose 1 to 1 month after dose 3 and from dose 4 to 1 month after dose 4, and serious AEs and newly diagnosed chronic medical conditions from dose 1 through 6 months after the last dose.

RESULTS

Participants received PCV20 (N = 1000) or PCV13 (N = 504); 91.7% received all 4 doses. The frequencies of local reactions and systemic events were generally similar in PCV20 and PCV13 groups, with most reported as mild or moderate. The most common local reaction was injection site pain (PCV20, 24.7% to 40.5%; PCV13, 26.8% to 42.0%); irritability was the most common systemic event (PCV20, 54.8% to 68.2%; PCV13, 54.7% to 68.5%). AE frequencies were similar in both groups. No serious AEs were related to study vaccines. Few newly diagnosed chronic medical conditions were reported (2.8% in both groups). PCV20 was safe across multiple countries, in late preterm infants, and when administered with other vaccines.

CONCLUSIONS

A 4-dose series of PCV20 had a tolerability and safety profile similar to that of PCV13.

Burden of Pneumococcal Disease in Young Children Due to Serotypes Contained in Different Pneumococcal Conjugate Vaccines in Eight Asian Countries and Territories

BACKGROUND

Pneumococcal disease (PD) is a major cause of morbidity and mortality in young children in Asia and globally. Pneumococcal conjugate vaccines (PCVs) have significantly reduced the burden of PD when included in pediatric national immunization programs (NIPs). This study estimates the clinical and economic burden of PD due to serotypes contained in different PCVs in children aged < 5 years in eight Asian countries/territories.

METHODS

Based on published data, a cohort-based decision analytic model was used to estimate annual PD cases, deaths, and direct medical costs associated with serotypes contained in PCV10, PCV13, PCV15, and PCV20.

RESULTS

PD incidence rates were lower in regions with PCV13 in their NIP than those without. Serotypes contained in higher but not lower valency PCVs resulted in a significant incremental clinical and economic burden, although the difference between PCV13 and PCV15 serotypes was generally small. Moving from PCV13 to PCV20 was estimated to result in greater clinical and economic burden reductions.

CONCLUSIONS

This study demonstrates the remaining and incremental burden of PD from PCV10 to PCV20 serotypes in young children in selected Asian regions. Extending NIP access to higher-valency PCVs with broader serotype coverage and improving vaccine uptake will help prevent morbidity and deaths and save healthcare costs.

Re-evaluating the impact and cost-effectiveness of pneumococcal conjugate vaccine introduction in 112 low-income and middle-income countries in children younger than 5 years: a modelling study

BACKGROUND

Streptococcus pneumoniae has been estimated to cause 9·18 million cases of pneumococcal pneumonia, meningitis, and invasive non-pneumonia non-meningitis disease and 318 000 deaths among children younger than 5 years in 2015. We estimated the potential impact and cost-effectiveness of pneumococcal conjugate vaccine (PCV) introduction.

METHODS

We updated our existing pseudodynamic model to estimate the impact of 13-valent PCV (PCV13) in 112 low-income and middle-income countries by adapting our previously published pseudodynamic model with new country-specific evidence on vaccine coverage, burden, and post-introduction vaccine impact from WHO-UNICEF estimates of national immunisation coverage and a global burden study. Deaths, disability-adjusted life-years (DALYs), and cases averted were estimated for children younger than 5 years born between 2000 and 2030. We used specific PCV coverage in each country and a hypothetical scenario in which coverage increased to diphtheria-tetanus-pertussis (DTP) levels. We conducted probabilistic uncertainty analyses.

FINDINGS

Using specific vaccine coverage in countries, we estimated that PCV13 could prevent 697 000 (95% credibility interval 359 000-1 040 000) deaths, 46·0 (24·0-68·9) million DALYs, and 131 (89·0-172) million cases in 112 countries between 2000 and 2030. PCV was estimated to prevent 5·3% of pneumococcal deaths in children younger than 5 years during 2000-30. The incremental cost of vaccination would be I$851 (510-1530) per DALY averted. If PCV coverage were increased to DTP coverage in 2020, PCV13 could prevent an additional 146 000 (75 500-219 000) deaths.

INTERPRETATION

The inclusion of real-world evidence from lower-income settings revealed that delays in PCV roll-out globally and low PCV coverage have cost many lives. Countries with delays in vaccine introduction or low vaccine coverage have experienced many PCV-preventable deaths. These findings underscore the importance of rapidly scaling up PCV to achieve high coverage and maximise vaccine impact.

FUNDING

Bill & Melinda Gates Foundation and Gavi, the Vaccine Alliance.

Serotype distribution of invasive pneumococcal disease from countries of the WHO Africa, Americas, Eastern Mediterranean, South-East Asia, and Western Pacific regions: a systematic literature review from 2010 to 2021

Background

Most publications on invasive pneumococcal disease (IPD) serotype distribution are from about 20 countries (Australia, Canada, China, European Union members, Japan, New Zealand, South Korea, and USA). Here, we reviewed the literature among underrepresented countries in the Americas (AMRO), Africa (AFRO), Eastern Mediterranean (EMRO), South-East Asia (SEARO), and Western Pacific (WPRO) WHO regions.

Methods

We performed a systematic review of the most recent IPD serotype surveillance publications (from 01/01/2010 to 31/12/2021, Medline/Embase) in those WHO regions. Selection criteria were delineated by contemporality, within-country geographical scope, and number of samples. Reported serotype distributions for each country were stratified by age group, pneumococcal conjugate vaccine (PCV) serotype category (considering undifferentiated serotypes), and PCV program period (pre-PCV, intermediate, or PCVhv [higher valency PCV formulation]). Pre-PCV period pooled data estimated PCV serotype category distribution by age group across WHO regions, while for the PCVhv period, country-level dataset tables were prepared.

Results

Of 2,793 publications screened, 107 were included (58 pediatric, 11 adult, 37 all ages, and one comprising every age group). One-third of eligible countries (51/135) published serotype distribution, ranging from 30 to 43% by WHO region. Considering number of samples per WHO region, a few countries prevailed: AMRO (Brazil), AFRO (South Africa, Malawi, and Burkina Faso), and WPRO (Taiwan). In the pre-PCV period, PCV13 formulation serotypes predominated: ranging from 74 to 85% in children and 58-86% in adults in the different WHO regions. The PCVhv period represented half of the most recent IPD surveillance by countries (26/51). Undifferentiated serotypes represented >20% of IPD from most countries (34/51).

Conclusion

Ubiquity of undifferentiated serotypes among the publications could constrain estimates of PCV program impact and of serotype coverage for newer PCVhv formulations; consequently, we recommend that countries favor techniques that identify serotypes specifically and, rather than reporting PCV formulation serotype distributions, provide serotype results individually.

Systematic review registration

The protocol has been prospectively registered at PROSPERO, identifier: CRD42021278501. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=278501.

A Phase 3, Single-arm Trial to Evaluate the Safety and Immunogenicity of a 20-Valent Pneumococcal Conjugate Vaccine in Healthy Children 15 Months Through <18 Years of Age

BACKGROUND

A 20-valent pneumococcal conjugate vaccine (PCV20), containing 13-valent PCV (PCV13) components and 7 additional polysaccharide conjugates, was developed to extend protection for pneumococcal disease. This phase 3 study assessed the safety and immunogenicity of PCV20 in children.

METHODS

In this single-arm study, children (≥15 months-<18 years of age) received 1 dose of PCV20. Children <5 years of age had ≥3 prior doses of PCV13; children ≥5 years were recruited regardless of previous PCV receipt. Serotype-specific IgG concentrations and opsonophagocytic activity (OPA) titers were measured before and 1 month after PCV20. Local reactions and systemic events, adverse events (AEs), serious AEs, and newly diagnosed chronic medical conditions were collected.

RESULTS

Of 839 enrolled participants, 831 (>99%) were vaccinated, and 819 (>97%) completed all study visits. Local reactions and systemic events were mostly mild to moderate in severity. No serious AEs were considered PCV20-related. IgG geometric mean fold rises (GMFRs) from before to 1 month after PCV20 ranged from 27.9-1847.7 (7 additional serotypes) and 2.9-44.9 (PCV13 serotypes) in children <5 years of age, and 10.5-187.7 (7 additional serotypes) and 4.3-127.9 (PCV13 serotypes) in children ≥5 years old. OPA GMFRs from before to 1 month after PCV20 ranged from 12.4-983.6 to 2.8-52.9 in children <5 years of age and from 11.5-499.0 to 5.3-147.9 in children ≥5 years of age.

CONCLUSIONS

Among children ≥15 months through <18 years of age, PCV20 was well tolerated and induced robust responses to all 20 serotypes, supporting the use of PCV20 in children.

A Phase Three Study of the Safety and Immunogenicity of a Four-dose Series of 20-Valent Pneumococcal Conjugate Vaccine in Healthy Infants

BACKGROUND

The 20-valent pneumococcal conjugate vaccine (PCV20) was developed to extend pneumococcal disease protection beyond 13-valent PCV (PCV13).

METHODS

This phase 3, double-blind study conducted in the United States/Puerto Rico evaluated PCV20 safety and immunogenicity. Healthy infants were randomized to receive a 4-dose series of PCV20 or PCV13 at 2, 4, 6 and 12-15 months old. Objectives included demonstrating noninferiority (NI) of PCV20 to PCV13 immunoglobulin G (IgG) geometric mean concentrations after doses 3 and 4 and percentages of participants with predefined IgG concentrations after dose 3, with 7 additional PCV20 serotypes compared with the lowest result among vaccine serotypes in the PCV13 group. Safety assessments included local reactions, systemic events, adverse events, serious adverse events and newly diagnosed chronic medical conditions.

RESULTS

Overall, 1991 participants were vaccinated (PCV20, n = 1001; PCV13, n = 990). For IgG geometric mean concentrations 1 month after both doses 3 and 4, all 20 serotypes met NI criteria (geometric mean ratio lower 2-sided 95% confidence interval > 0.5). For percentages of participants with predefined IgG concentrations after dose 3, NI (percentage differences lower 2-sided 95% confidence interval > -10%) was met for 8/13 matched serotypes and 6/7 additional serotypes; 4 serotypes missed the statistical NI criterion by small margins. PCV20 also elicited functional and boosting responses to all 20 serotypes. The safety profile of PCV20 was similar to PCV13.

CONCLUSION

A 4-dose series of PVC20 was well tolerated and elicited robust serotype-specific immune responses expected to help protect infants and young children against pneumococcal disease due to the 20 vaccine serotypes. Clinical trial registration: NCT04382326.

Phase 3 Safety and Immunogenicity Study of a Three-dose Series of Twenty-valent Pneumococcal Conjugate Vaccine in Healthy Infants and Toddlers

BACKGROUND

Global pediatric immunization programs with pneumococcal conjugate vaccines (PCVs) have reduced vaccine-type pneumococcal disease, but a substantial disease burden of non-PCV serotypes remains.

METHODS

This phase 3, randomized (1:1), double-blind study evaluated safety and immunogenicity of 20-valent PCV (PCV20) relative to 13-valent PCV (PCV13) in healthy infants. Participants received 2 infant doses and a toddler dose of PCV20 or PCV13, with diphtheria-tetanus-acellular pertussis combination vaccine at all doses and measles, mumps, rubella and varicella vaccines at the toddler dose. Primary pneumococcal immunogenicity objectives were to demonstrate noninferiority (NI) of PCV20 to PCV13 for immunoglobulin G geometric mean concentrations after infant and toddler doses and percentages of participants with predefined serotype-specific immunoglobulin G concentrations after infant doses. Safety endpoints included local reactions, systemic events and adverse events.

RESULTS

Overall, 1204 participants were vaccinated (PCV20, n = 601; PCV13, n = 603). One month after the toddler dose, 19/20 serotypes met NI for immunoglobulin G geometric mean concentrations; serotype 6B narrowly missed NI [PCV20/PCV13 geometric mean ratio: 0.57 (2-sided 95% confidence interval: 0.48-0.67); NI criterion: lower 2-sided 95% confidence interval >0.5]. Sixteen/twenty serotypes met NI for ≥1 primary objective after 2 infant doses. PCV20 induced robust opsonophagocytic activity, and boosting responses were observed for all vaccine serotypes, including those missing statistical NI. The safety/tolerability profile of PCV20 was like that of PCV13.

CONCLUSIONS

PCV20 3-dose series in infants was safe and elicited robust immune responses. Based on these results and PCV13 experience, PCV20 3-dose series is expected to be protective for all 20 vaccine serotypes. NCT04546425.

Clinical and economic burden of acute otitis media caused by Streptococcus pneumoniae in European children, after widespread use of PCVs-A systematic literature review of published evidence

BACKGROUND

Acute otitis media (AOM) is a common childhood disease frequently caused by Streptococcus pneumoniae. Pneumococcal conjugate vaccines (PCV7, PCV10, PCV13) can reduce the risk of AOM but may also shift AOM etiology and serotype distribution. The aim of this study was to review estimates from published literature of the burden of AOM in Europe after widespread use of PCVs over the past 10 years, focusing on incidence, etiology, serotype distribution and antibiotic resistance of Streptococcus pneumoniae, and economic burden.

METHODS

This systematic review included published literature from 31 European countries, for children aged ≤5 years, published after 2011. Searches were conducted using PubMed, Embase, Google, and three disease conference websites. Risk of bias was assessed with ISPOR-AMCP-NPC, ECOBIAS or ROBIS, depending on the type of study.

RESULTS

In total, 107 relevant records were identified, which revealed wide variation in study methodology and reporting, thus limiting comparisons across outcomes. No homogenous trends were identified in incidence rates across countries, or in detection of S. pneumoniae as a cause of AOM over time. There were indications of a reduction in hospitalization rates (decreases between 24.5-38.8% points, depending on country, PCV type and time since PCV introduction) and antibiotic resistance (decreases between 14-24%, depending on country), following the widespread use of PCVs over time. The last two trends imply a potential decrease in economic burden, though this was not possible to confirm with the identified cost data. There was also evidence of an increase in serotype distributions towards non-vaccine serotypes in all of the countries where non-PCV serotype data were available, as well as limited data of increased antibiotic resistance within non-vaccine serotypes.

CONCLUSIONS

Though some factors point to a reduction in AOM burden in Europe, the burden still remains high, residual burden from uncovered serotypes is present and it is difficult to provide comprehensive, accurate and up-to-date estimates of said burden from the published literature. This could be improved by standardised methodology, reporting and wider use of surveillance systems.

Effect of Pneumococcal Conjugate Vaccine on Pneumonia Incidence Rates among Children 2-59 Months of Age, Mongolia, 2015-2021

Starting in June 2016, the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced into the routine immunization program of Mongolia by using a 2+1 dosing schedule, phased by district. We used prospective hospital surveillance to evaluate the vaccine's effect on pneumonia incidence rates among children 2-59 months of age over a 6-year period. Of 17,607 children with pneumonia, overall adjusted incidence rate ratios showed decreased primary endpoint pneumonia, very severe pneumonia, and probable pneumococcal pneumonia until June 2021. Results excluding and including the COVID-19 pandemic period were similar. Pneumonia declined in 3 districts that introduced PCV13 with catch-up campaigns but not in the 1 district that did not. After PCV13 introduction, vaccine-type pneumococcal carriage prevalence decreased by 44% and nonvaccine-type carriage increased by 49%. After PCV13 introduction in Mongolia, the incidence of more specific pneumonia endpoints declined in children 2-59 months of age; additional benefits were conferred by catch-up campaigns.

Cost-effectiveness analysis of a maternal pneumococcal vaccine in low-income, high-burden settings such as Sierra Leone

Maternal pneumococcal vaccines have been proposed as a method of protecting infants in the first few months of life. In this paper, we use results from a dynamic transmission model to assess the cost-effectiveness of a maternal pneumococcal polysaccharide vaccine from both healthcare and societal perspectives. We estimate the costs of delivering a maternal pneumococcal polysaccharide vaccine, the healthcare costs averted, and productivity losses avoided through the prevention of severe pneumococcal outcomes such as pneumonia and meningitis. Our model estimates that a maternal pneumococcal program would cost $606 (2020 USD, 95% prediction interval 437 to 779) from a healthcare perspective and $132 (95% prediction interval -1 to 265) from a societal perspective per DALY averted for one year of vaccine delivery. Hence, a maternal pneumococcal vaccine would be cost-effective from a societal perspective but not cost-effective from a healthcare perspective using Sierra Leone's GDP per capita of $527 as a cost-effectiveness threshold. Sensitivity analysis demonstrates how the choice to discount ongoing health benefits determines whether the maternal pneumococcal vaccine was deemed cost-effective from a healthcare perspective. Without discounting, the cost per DALY averted would be $292 (55% of Sierra Leone's GDP per capita) from a healthcare perspective. Further, the cost per DALY averted would be $142 (27% GDP per capita) from a healthcare perspective if PPV could be procured at the same cost relative to PCV in Sierra Leone as on the PAHO reference price list. Overall, our paper demonstrates that maternal pneumococcal vaccines have the potential to be cost-effective in low-income settings; however, the likelihood of low-income countries self-financing this intervention will depend on negotiations with vaccine providers on vaccine price. Vaccine price is the largest program cost driving the cost-effectiveness of a future maternal pneumococcal vaccine.

Estimating the Clinical and Economic Impact of Switching from the 13-Valent Pneumococcal Conjugate Vaccine (PCV13) to Higher-Valent Options in Greek Infants

In June 2010, Greece introduced the 13-valent pneumococcal conjugate vaccine (PCV13) for pediatric vaccination and has since observed a large decrease in pneumococcal disease caused by these vaccine serotypes, yet the disease prevalence of non-vaccine serotypes has increased. Two higher-valent conjugate vaccines, a 15-valent (PCV15) and a 20-valent (PCV20), were developed to improve serotype coverage and combat serotype replacement. A decision-analytic model was adapted to the Greek setting using historical pneumococcal disease trends from PCV13 to forecast future clinical and economic outcomes of higher-valent PCVs over a 10-year period (2023-2033). The model estimated outcomes related to invasive pneumococcal disease (IPD), hospitalized and non-hospitalized pneumonia, and otitis media (OM) resulting from a switch in vaccination programs to PCV15 in 2023 or switching to PCV20 in 2024. Cost-effectiveness was evaluated from the third-party payer's perspective in the Greek healthcare system. Compared to implementing PCV15 one year earlier, switching from PCV13 to PCV20 in 2024 was estimated to be a cost-saving strategy by saving the Greek health system over EUR 50 million in direct medical costs and averting over 250 IPD cases, 54,800 OM cases, 8450 pneumonia cases, and 255 deaths across all ages over a 10-year period.

Pneumococcal Disease: Global Disease Prevention Strategies with a Focus on the Challenges in Iraq

Pneumococcal disease is a global public health concern that significantly contributes to clinical disease burden and economic burden. Patients frequently afflicted are young children and older adults, as well as the immunocompromised population. Immunization is the most effective public health strategy to combat pneumococcal disease and several vaccine formulations have been developed in this regard. Although vaccines have had a significant global impact in reducing pneumococcal disease, there are several barriers to its success in Iraq. The war and conflict situation, increasing economic crises and poverty, poor vaccine accessibility in the public sector, and high vaccine costs are a few of the major obstacles that impede a successful immunization program. The last reported third dose pneumococcal conjugate vaccine coverage for Iraq was 37% in 2019, which is expected to reduce even further owing to the COVID-19 pandemic. Thus, strategies and policies to improve pneumococcal vaccine availability and coverage need to be strengthened to achieve maximum benefits of immunization. In the current review, we provide an overview of the existing knowledge on pneumococcal disease-prevention strategies across the globe. The main aim of this manuscript is to discuss the current status and challenges of pneumococcal vaccination in Iraq as well as the strategies to prevent pneumococcal infections.

A Phase III, multicenter, randomized, double-blind, active comparator-controlled study to evaluate the safety, tolerability, and immunogenicity of V114 compared with PCV13 in healthy infants (PNEU-PED-EU-1)

BACKGROUND

V114 (15-valent pneumococcal conjugate vaccine [PCV]) contains all serotypes in 13-valent PCV (PCV13) and additional serotypes 22F and 33F. This study evaluated safety and immunogenicity of V114 compared with PCV13 in healthy infants, and concomitant administration with DTPa-HBV-IPV/Hib and rotavirus RV1 vaccines.

METHODS

V114 and PCV13 were administered in a 2+1 schedule at 2, 4, and 11-15 months of age. Adverse events (AEs) were collected on Days 1-14 following each vaccination. Serotype-specific anti-pneumococcal immunoglobulin G (IgG) was measured 30 days post-primary series (PPS), immediately prior to a toddler dose, and 30 days post-toddler dose (PTD). Primary objectives included non-inferiority of V114 to PCV13 for 13 shared serotypes and superiority of V114 to PCV13 for the two additional serotypes.

RESULTS

1184 healthy infants 42-90 days of age were randomized 1:1 to V114 (n = 591) or PCV13 (n = 593). Proportions of participants with solicited AEs and serious AEs were comparable between vaccination groups. V114 met pre-specified non-inferiority criteria for all 13 shared serotypes, based on the difference in proportions of participants with serotype-specific IgG concentrations ≥0.35 μg/mL (response rate; lower bound of two-sided 95% confidence interval [CI] >-10.0) and IgG geometric mean concentration (GMC) ratios (lower bound of two-sided 95% CI >0.5), and pre-specified superiority criteria for serotypes 22F and 33F (lower bound of two-sided 95% CI >10.0 for response rates and >2.0 for GMC ratios). Antibody responses to DTPa-HBV-IPV/Hib and RV1 vaccines met pre-specified non-inferiority criteria, based on antigen-specific response rates to DTPa-HBV-IPV/Hib and anti-rotavirus IgA geometric mean titers.

CONCLUSIONS

After a 2+1 schedule, V114 elicited non-inferior immune responses to 13 shared serotypes and superior responses to the two additional serotypes compared with PCV13, with comparable safety profile. These results support the routine use of V114 in infants.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04031846; EudraCT: 2018-003787-31.

Safety, tolerability, and immunogenicity of V114 pneumococcal vaccine compared with PCV13 in a 2+1 regimen in healthy infants: A phase III study (PNEU-PED-EU-2)

BACKGROUND

This phase III study evaluated safety, tolerability, and immunogenicity of V114 (15-valent pneumococcal conjugate vaccine) in healthy infants. V114 contains all 13 serotypes in PCV13 and additional serotypes 22F and 33F.

METHODS

Healthy infants were randomized to two primary doses and one toddler dose (2+1 regimen) of V114 or PCV13 at 3, 5, and 12 months of age; diphtheria, tetanus, pertussis (DTaP), inactivated poliovirus (IPV), Haemophilus influenzae type b (Hib), hepatitis B (HepB) vaccine was administered concomitantly. Adverse events (AEs) were collected on Days 1-14 following each vaccination. Serotype-specific anti-pneumococcal immunoglobulin G (IgG) was measured 30 days post-primary series, immediately prior to toddler dose, and 30 days post-toddler dose. Primary objectives included non-inferiority of V114 to PCV13 for 13 shared serotypes and superiority of V114 to PCV13 for serotypes 22F and 33F.

RESULTS

1191 healthy infants were randomized to V114 (n = 595) or PCV13 (n = 596). Proportions of participants with solicited AEs and serious AEs were comparable between groups. V114 met non-inferiority criteria for 13 shared serotypes, based on difference in proportions with serotype-specific IgG ≥0.35 μg/mL (lower bound of two-sided 95% confidence interval [CI] >-10.0) and IgG geometric mean concentration (GMC) ratios (lower bound of two-sided 95% CI >0.5) at 30 days post-toddler dose. V114 met superiority criteria for serotypes 22F and 33F, based on response rates (lower bound of two-sided 95% CI >10.0) and IgG GMC ratios (lower bound of two-sided 95% CI >2.0) at 30 days post-toddler dose. Antibody responses to DTaP-IPV-Hib-HepB met non-inferiority criteria, based on antigen-specific response rates.

CONCLUSION

A two-dose primary series plus toddler dose of V114 was well-tolerated in healthy infants. Compared with PCV13, V114 provided non-inferior immune responses to 13 shared serotypes and superior immune responses to additional serotypes 22F and 33F.

Estimated global public health and economic impact of COVID-19 vaccines in the pre-omicron era using real-world empirical data

BACKGROUND

Limited data are available describing the global impact of COVID-19 vaccines. This study estimated the global public health and economic impact of COVID-19 vaccines before the emergence of the Omicron variant.

METHODS

A static model covering 215 countries/territories compared the direct effects of COVID-19 vaccination to no vaccination during 13 December 2020-30 September 2021. After adjusting for underreporting of cases and deaths, base case analyses estimated total cases and deaths averted, and direct outpatient and productivity costs saved through averted health outcomes. Sensitivity analyses applied alternative model assumptions.

RESULTS

COVID-19 vaccines prevented an estimated median (IQR) of 151.7 (133.7-226.1) million cases and 620.5 (411.1-698.1) thousand deaths globally through September 2021. In sensitivity analysis applying an alternative underreporting assumption, median deaths averted were 2.1 million. Estimated direct outpatient cost savings were $21.2 ($18.9-30.9) billion and indirect savings of avoided productivity loss were $135.1 ($121.1-206.4) billion, yielding a total cost savings of $155 billion globally through averted infections.

CONCLUSIONS

Using a conservative modeling approach that considered direct effects only, we estimated that COVID-19 vaccines have averted millions of infections and deaths, generating billions of cost savings worldwide, which underscore the continued importance of vaccination in public health response to COVID-19.

Impact of national pneumococcal vaccination program on invasive pneumococcal diseases in South Korea

Following the introduction of pneumococcal conjugate vaccines (PCVs), the rate of invasive pneumococcal disease (IPD) declined, however, IPDs replaced by serotypes that are not included in the vaccine have emerged. We describe the epidemiology of IPD in South Korea over a 4.5-year period, encompassing the impact following introduction of PCV10/13 and PPSV23 into the public immunization program, and assess serotype dynamics in pediatric and adult population. This was a nationwide, retrospective review of surveillance of all IPD cases in Korea between September 2014 to December 2019. We analyzed VT13 (serotypes included in 13-valent conjugate vaccine) and NVT (nonvaccine type) cases by age, sex, IPD type, vaccination status, and deaths. A total of 893 cases with serotype data were included; 306 (34%) VT13 cases and 587 (66%) NVT cases. Serotype 3 (n = 155) was the most common VT13 serotype, followed by serotypes 19A (n = 70) and 14 (n = 28). Among the NVTs, serotype 10A (n = 74) was the most common serotype, followed by serotypes 23A (n = 60) and 34 (n = 58). Persons who had PCV13 vaccination were at lower risk (aOR = 0.11, 95% CI 0.02–0.73, P = 0.022) of death compared to unvaccinated persons. Introduction of PCV10/13 and PPSV23 vaccination program has had different impacts on the serotype-specific IPD across age groups. The most common serotypes included serotypes 3 and 19A (VT13), and 10A, 23A, and 34 (NVT). Our findings suggest continued monitoring in the midst of new vaccine development, and a need to develop novel strategies to mitigate the IPDs from emerging pneumococcal serotypes.

Modelling the impact of maternal pneumococcal vaccination on infant pneumococcal disease in low-income settings

Pneumococcal disease is a leading cause of mortality in young children. The largest burden of pneumococcal disease is in the first six months of life before protection from a complete schedule of direct immunisation is possible. Maternal pneumococcal vaccination has been proposed as a strategy for protection in this period of early childhood; however, limited clinical trial data exists. In this study, we developed an age-structured compartmental mathematical model to estimate the impact of maternal pneumococcal vaccination. Our model demonstrates how maternal pneumococcal vaccination could prevent 73% (range 49-88%) of cases in those aged <1 month and 55% (range 36-66%) in those 1-2 months old. This translates to an estimated 17% reduction in deaths due to invasive pneumococcal disease in children under five. Overall, this study demonstrates the potential for maternal pneumococcal vaccination to meaningfully reduce the burden of infant pneumococcal disease, supporting the case for appropriate field-based clinical studies.

Validation of Fourier Transform Infrared Spectroscopy for Serotyping of Streptococcus pneumoniae

Fourier transform infrared (FT-IR) spectroscopy (IR Biotyper; Bruker) allows highly discriminatory fingerprinting of closely related bacterial strains. In this study, FT-IR spectroscopy-based capsular typing of Streptococcus pneumoniae was validated as a rapid, cost-effective, and medium-throughput alternative to the classical phenotypic techniques. A training set of 233 strains was defined, comprising 34 different serotypes and including all 24 vaccine types (VTs) and 10 non-vaccine types (NVTs). The acquired spectra were used to (i) create a dendrogram where strains clustered together according to their serotypes and (ii) train an artificial neural network (ANN) model to predict unknown pneumococcal serotypes. During validation using 153 additional strains, we reached 98.0% accuracy for determining serotypes represented in the training set. Next, the performance of the IR Biotyper was assessed using 124 strains representing 59 non-training set serotypes. In this setting, 42 of 59 serotypes (71.1%) could be accurately categorized as being non-training set serotypes. Furthermore, it was observed that comparability of spectra was affected by the source of the Columbia medium used to grow the pneumococci and that this complicated the robustness and standardization potential of FT-IR spectroscopy. A rigorous laboratory workflow in combination with specific ANN models that account for environmental noise parameters can be applied to overcome this issue in the near future. The IR Biotyper has the potential to be used as a fast, cost-effective, and accurate phenotypic serotyping tool for S. pneumoniae.

The broader impacts of otitis media and sequelae for informing economic evaluations of pneumococcal conjugate vaccines

INTRODUCTION

Otitis media (OM) is a common childhood infection. Pneumococcal conjugate vaccines (PCVs) prevent OM episodes, thereby reducing short- and long-term clinical, economic, humanistic, and societal consequences. Most economic evaluations of PCVs focus on direct health gains and cost savings from prevented acute episodes but do not fully account for the broader societal impacts of OM prevention.

AREAS COVERED

This review explores the broader burden of OM on children, caregivers, and society to better inform future economic evaluations of PCVs.

EXPERT OPINION

OM causes a substantial burden to society through long-term sequelae, productivity losses, reduced quality of life for children and caregivers, and contribution to antimicrobial resistance from inappropriate antibiotic use. The effect of PCVs on acute OM has been recognized globally, yet the broader impact has not been consistently quantified, studied, or communicated. Economic evaluations of PCVs must evolve to include broader effects for patients, caregivers, and society from OM prevention. Future PCVs with broader coverage may further reduce OM incidence and antimicrobial resistance, but optimal uptake will depend on increasing the recognition and use of novel frameworks that include broader benefits. Communicating the full value of PCVs to decision makers may result in wider access and positive societal returns.

The Impact of the 13-Valent Pneumococcal Conjugate Vaccine on Otitis Media-Related Antibiotic Use Among Young Children in Tennessee, USA

Otitis media (OM) is a leading cause of pediatric antibiotic use. Introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) led to reductions in OM among US children, though its impact on OM-related antibiotic use remains unclear. Among 499 683 Tennessee children <2 years of age, the OM-related antibiotic fill rate was stable after PCV13 introduction.

Clinical and Economic Burden of Pneumococcal Disease Due to Serotypes Contained in Current and Investigational Pneumococcal Conjugate Vaccines in Children Under Five Years of Age

INTRODUCTION

The widespread implementation of pneumococcal conjugate vaccines (PCVs) has significantly reduced the burden of pneumococcal disease around the world. Although licensed 10-valent (PCV10) and 13-valent (PCV13) vaccines have considerably reduced mortality and morbidity, a sizeable disease burden attributable to serotypes not contained in these PCVs remains. This study aimed to estimate the annual clinical and economic burden of pneumococcal disease attributable to licensed (PCV10 and PCV13) and investigational PCVs, notably 15-valent (PCV15) and 20-valent (PCV20) vaccines, in 13 countries in children under 5 years of age.

METHODS

A decision-analytic model was created to aggregate total cases [inclusive of invasive pneumococcal disease (IPD), pneumonia, and otitis media (OM)], deaths, and direct costs in each country of interest [stratified by PCV10/PCV13 countries, depending on national immunization programs (NIPs)] over 1 year, using up to the three most recent years of available serotype coverage data. Data inputs were sourced from local databases, surveillance reports, and published literature.

RESULTS

In 5 PCV10 NIPs (Austria, Finland, Netherlands, New Zealand, Sweden), most remaining PCV20-type disease was due to PCV13-unique serotypes (30-85%), followed by PCV20-unique (9-50%), PCV15-unique (4-15%), and PCV10-unique (2-14%) serotypes. In 8 PCV13 NIPs (Australia, Canada, France, Germany, Italy, South Korea, Spain, United Kingdom), most remaining PCV20-type disease was caused by PCV20-unique serotypes (16-69%), followed by PCV13-unique (11-54%), PCV15-unique (2-33%), and PCV10-unique serotypes (3-19%). Across all countries, PCV20 serotypes caused 3000 to 345,000 cases of disease and cost between $1.3 and $44.9 million USD annually with variability driven by population size, NIP status, and epidemiologic inputs. In aggregate, PCV20 serotypes caused 1,234,000 cases and $213.5 million in annual direct medical costs in children under 5 years of age.

CONCLUSION

Despite the success of PCV10 and PCV13 in reducing pneumococcal disease, a substantial clinical and economic burden remains due to serotypes contained in investigational vaccines.

Public health impact of pneumococcal conjugate vaccination: a review of measurement challenges

INTRODUCTION

Modeling analyses have attempted to quantify the global impact of pneumococcal conjugate vaccines (PCVs) on pneumococcal disease (PD), however these pediatric models face several challenges in obtaining comprehensive impact measurements.

AREAS COVERED

We present several measurement challenges and discuss examples from recently published pediatric modeling evaluations. Challenges include estimating the number of infants fully or partially vaccinated with PCVs, inclusion of indirect effects of vaccination, accounting for various dosing schedules, capturing effect of PCVs on nonspecific, noninvasive PD, and inclusion of adult PCV use.

EXPERT OPINION

The true impact of PCVs has been consistently underestimated in published analyses due to multiple measurement challenges. Nearly 100 million adults are estimated to have received PCV13 over the last decade globally, potentially preventing up to 662 thousand cases of PD. Approximately 4.1 million cases of invasive PD alone may have been averted through indirect protection. Estimates of PCV impact on noninvasive PD remain a challenge due to altered epidemiology. Program switches, incomplete vaccination, and private market uptake among children also confound PD impact estimates. Taken together, the number of averted PD cases from PCV use in the last ten years may be up to three times higher than estimated in previous studies.

Pneumococcal Conjugated Vaccines Decreased Acute Otitis Media Burden: A Population-Based Study in Israel

OBJECTIVE

To study time trends in all-cause acute otitis media (AOM) burden by calculating incidence rates of AOM episodes and recurrent acute otitis media (rAOM) cases in highly immunized pediatric population during the pre- and post-pneumococcal conjugated vaccine (PCV) years.

STUDY DESIGN

In this population-based study, AOM episodes and rAOM cases were identified in Clalit Health Services-insured Israeli children aged 0-10 years between 2005 and 2018 by using a data-sharing platform. Because a near-sequential implementation of PCV-7/PCV-13 occurred within a 1-year period (2009/2010), we compared AOM visits before (2005-July 2009) and after (August 2009-2018) the introduction of PCVs. We focused on children younger than 2 years of age, who are the target population of PCVs and are at AOM peak age.

RESULTS

We identified 805 389 AOM episodes contributed by 270 137 children. The median number of AOM episodes was 2 (IQR 1-4). A downward trend of incidence rates of AOM episodes was observed during the post-PCV years in children younger than age 9 years (P < .001). The largest decrease (21%) was observed in children younger than 1 year, from 807/1000 children during the pre-PCV years to 640/1000 during the post-PCV years (P < .001). An average annual decrease of ∼14/1000 AOM episodes was calculated in children younger than 1 year old (β = -13.39, 95% CI -16.25 to -10.53, P < .001). Of rAOM cases, documented in 84 237 (31.2%) children, 74% were in children younger than 2 years, and 55% were in boys. The risk to develop rAOM significantly decreased during the post-PCV years in children younger than 2 years (hazard ratio 0.893, 95% CI 0.878-0.908; P < .001).

CONCLUSIONS

AOM burden significantly decreased following PCVs introduction in highly immunized children.

Estimating the Public Health and Economic Impact of Introducing the 13-Valent Pneumococcal Conjugate Vaccine or 10-Valent Pneumococcal Conjugate Vaccines into State Immunization Programs in India

Introduction

Although the pneumococcal conjugate vaccine (PCV) has been introduced into select state immunization programs (SIPs) in India, many children remain unvaccinated. Recently, India’s Advisory Committee on Vaccines & Immunization Practices recommended PCV on the pediatric immunization schedule nationally. This study estimates the public health and economic impact of introducing either Pfizer’s 13-valent PCV (PCV13-PFE), GlaxoSmithKline’s 10-valent PCV (PCV10-GSK), or Serum Institute of India’s 10-valent PCV (PCV10-SII) into every pediatric SIP.

Methods

A model was developed to predict the disease cases, deaths, and costs associated with implementing PCV13-PFE, PCV10-GSK, or PCV10-SII in SIPs compared to no vaccination program across a 5-year period (2021–2025). State and national-level uptake rate and clinical and economic input parameters were collected from published literature. Disease outcomes included invasive pneumococcal disease, inpatient and outpatient pneumonia, and otitis media. Costs were estimated as vaccine-related costs and direct medical costs incurred to the healthcare system. Results were reported by individual state and aggregated nationally.

Results

Estimated over 5 years, implementing PCV13-PFE in SIPs could avert 12.1 million cases and save 626,512 lives among children under 5 years old compared to no vaccination. This corresponds to net national cost savings of over $1.0 billion. Both lower-valent PCVs are estimated to provide less economic savings than PCV13-PFE inclusive of vaccine-related costs. Compared with PCV13-PFE, implementing PCV10-GSK or PCV10-SII nationally is estimated to have a smaller public health impact, with PCV10-GSK averting 8.4 million cases (436,577 deaths) and PCV10-SII preventing 10.3 million cases (531,545 deaths) in India compared to no vaccination, respectively.

Conclusion

Implementation of PCV13-PFE throughout India is estimated to provide greater public health and economic benefits than PCV10-GSK or PCV10-SII SIPs. Our analysis highlights the substantial disease cases, deaths, and health system cost savings that may be realized from implementing PCV programs throughout India.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00498-4.

Twenty-Year Public Health Impact of 7- and 13-Valent Pneumococcal Conjugate Vaccines in US Children

Pneumococcal conjugate vaccines (PCVs) have been used in the United States since 2000. To assess the cumulative 20-year effect of PCVs on invasive pneumococcal disease (IPD) incidence among children <5 years of age, we analyzed Active Bacterial Core Surveillance data, conducted a literature review, and modeled expected and observed disease. We found that PCVs have averted >282,000 cases of IPD, including ≈16,000 meningitis, ≈172,000 bacteremia, and ≈55,000 bacteremic pneumonia cases. In addition, vaccination has prevented 97 million healthcare visits for otitis media, 438,914-706,345 hospitalizations for pneumonia, and 2,780 total deaths. IPD cases declined 91%, from 15,707 in 1997 to 1,382 in 2019. Average annual visits for otitis media declined 41%, from 78 visits/100 children before PCV introduction to 46 visits/100 children after PCV13 introduction. Annual pneumonia hospitalizations declined 66%-79%, from 110,000-175,000 in 1997 to 37,000 in 2019. These findings confirm the substantial benefits of PCVs for preventing IPD in children.

Retrospective Impact Analysis and Cost-Effectiveness of the Pneumococcal Conjugate Vaccine Infant Program in Australia

Australia introduced the 7-valent pneumococcal conjugate vaccine (7vPCV) on the universal infant National Immunisation Program (NIP) in 2005 and replaced it with the 13-valent pneumococcal conjugate vaccine (13vPCV) in 2011, both under a 3 + 0 schedule. The objective of this analysis was to quantify the clinical and economic impact of the universal infant PCV program in Australia from its introduction. A decision-analytic model was developed to estimate the historical impact of pneumococcal conjugate vaccine (PCV) programs in Australia from a direct health care perspective. Historical incidence of invasive pneumococcal disease (IPD), pneumonia, and otitis media (OM) were obtained from available Australian epidemiologic databases supplemented with published data. Costs were from Medicare Benefits Schedule in 2018 Australian dollars and utility weights from published sources. Historical observed changes in disease for the universal PCV NIP era (2005–2017) were compared against a “no-vaccine” scenario. The expected incidence for the no-vaccine scenario in years 2005–2017 was calculated using pre-universal PCV NIP era (2001–2004) data. Averted cases, deaths, incremental costs, and quality-adjusted life years (QALYs) were obtained by subtracting the vaccine scenario totals from the no-vaccine scenario totals. From the inclusion in the universal infant NIP, 7vPCV and 13vPCV are estimated to have prevented 1,770,024 cases of pneumococcal disease (IPD = 16,392; OM = 1,575,491; pneumonia = 102,059) and 1195 associated deaths. Over this period, there was a total 24,335 QALYs gained. Costs for the universal infant NIP were offset by $733 million direct costs saved, resulting in an incremental cost-effectiveness ratio of $3347 per QALY gained. PCVs have provided substantial public health and economic value from sustained use in Australia. Results are conservative, since long-term pneumococcal disease consequences and broader socioeconomic benefits were not considered. Maintaining 13vPCV on the Australian infant NIP under the newly implemented 2 + 1 schedule will likely provide more return on investment and sustained reductions in pneumococcal disease.