Effectiveness of the seven-valent and thirteen-valent pneumococcal conjugate vaccines in England: The indirect cohort design, 2006-2018

Effectiveness of 13-valent pneumococcal conjugate vaccine for prevention of invasive pneumococcal disease among children in the United States between 2010 and 2019: An indirect cohort study

BACKGROUND

A U.S. case-control study (2010-2014) demonstrated vaccine effectiveness (VE) for ≥ 1 dose of the thirteen-valent pneumococcal conjugate vaccine (PCV13) against vaccine-type (VT) invasive pneumococcal disease (IPD) at 86 %; however, it lacked statistical power to examine VE by number of doses and against individual serotypes.

METHODS

We used the indirect cohort method to estimate PCV13 VE against VT-IPD among children aged < 5 years in the United States from May 1, 2010 through December 31, 2019 using cases from CDC's Active Bacterial Core surveillance, including cases enrolled in a matched case-control study (2010-2014). Cases and controls were defined as individuals with VT-IPD and non-PCV13-type-IPD (NVT-IPD), respectively. We estimated absolute VE using the adjusted odds ratio of prior PCV13 receipt (1-aOR x 100 %).

RESULTS

Among 1,161 IPD cases, 223 (19.2 %) were VT cases and 938 (80.8 %) were NVT controls. Of those, 108 cases (48.4 %; 108/223) and 600 controls (64.0 %; 600/938) had received > 3 PCV13 doses; 23 cases (17.6 %) and 15 controls (2.4 %) had received no PCV doses. VE ≥ 3 PCV13 doses against VT-IPD was 90.2 % (95 % Confidence Interval75.4-96.1 %), respectively. Among the most commonly circulating VT-IPD serotypes, VE of ≥ 3 PCV13 doses was 86.8 % (73.7-93.3 %), 50.2 % (28.4-80.5 %), and 93.8 % (69.8-98.8 %) against serotypes 19A, 3, and 19F, respectively.

CONCLUSIONS

At least three doses of PCV13 continue to be effective in preventing VT-IPD among children aged < 5 years in the US. PCV13 was protective against serotypes 19A and 19F IPD; protection against serotype 3 IPD did not reach statistical significance.

Immunogenicity of Current and Next-Generation Pneumococcal Conjugate Vaccines in Children: Current Challenges and Upcoming Opportunities

Global use of pneumococcal conjugate vaccines (PCVs) with increasingly broader serotype coverage has helped to reduce the burden of pneumococcal disease in children and adults. In clinical studies comparing PCVs, higher-valency PCVs have met noninferiority criteria (based on immunoglobulin G geometric mean concentrations and response rates) for most shared serotypes. A numeric trend of declining immunogenicity against shared serotypes with higher-valency PCVs has also been observed; however, the clinical relevance is uncertain, warranting additional research to evaluate the effectiveness of new vaccines. Novel conjugation processes, carriers, adjuvants, and vaccine platforms are approaches that could help maintain or improve immunogenicity and subsequent vaccine effectiveness while achieving broader protection with increasing valency in pneumococcal vaccines.

Effects of PCV10 and PCV13 on pneumococcal serotype 6C disease, carriage, and antimicrobial resistance

BACKGROUND

The cross-protection of pneumococcal conjugate vaccines (PCV) against serotype 6C is not clearly documented, although 6C represents a substantial burden of pneumococcal disease in recent years. A systematic review by the World Health Organization that covered studies through 2016 concluded that available data were insufficient to determine if either PCV10 (which contains serotype 6B but not 6A) or PCV13 (containing serotype 6A and 6B) conferred protection against 6C.

METHODS

We performed a systematic review of randomized controlled trials and observational studies published between January 2010 - August 2022 (Medline/Embase), covering the direct, indirect, and overall effect of PCV10 and PCV13 against 6C invasive pneumococcal disease (IPD), non-IPD, nasopharyngeal carriage (NPC), and antimicrobial resistance (AMR).

RESULTS

Of 2548 publications identified, 112 were included. Direct vaccine effectiveness against 6C IPD in children ranged between 70 and 85 % for ≥ 1 dose PCV13 (n = 3 studies), was 94 % in fully PCV13 vaccinated children (n = 2), and -14 % for ≥ 1 dose of PCV10 (n = 1). Compared to PCV7, PCV13 efficacy against 6C NPC in children was 66 % (n = 1). Serotype 6C IPD rates or NPC prevalence declined post-PCV13 in most studies in children (n = 5/6) and almost half of studies in adults (n = 5/11), while it increased post-PCV10 for IPD and non-IPD in all studies (n = 6/6). Changes in AMR prevalence were inconsistent.

CONCLUSIONS

In contrast to PCV10, PCV13 vaccination consistently protected against 6C IPD and NPC in children, and provided some level of indirect protection to adults, supporting that serotype 6A but not 6B provides cross-protection to 6C. Vaccine policy makers and regulators should consider the effects of serotype 6A-containing PCVs against serotype 6C disease in their decisions.

Protective effect of PCV13 against all-cause hospitalized pneumonia in children in Beijing, China: real-world evidence

BACKGROUND

The study evaluated the protective effect of 13-valent pneumococcal polysaccharide conjugate vaccine (PCV13) against all-cause hospitalized pneumonia in children in Beijing.

METHODS

Based on the vaccination record and inpatient medical record database of Beijing, children born in 2017 in Beijing, matched by age, gender, and district of the children with the ratio of 1:4, were selected as the vaccinated and unvaccinated groups according whether if vaccinated with PCV13. The incidence rate and 95 % confidence interval (95 %CI), vaccine effectiveness (VE) and direct medical costs of all-cause hospitalized pneumonia were calculated and compared within the same period of 12 months, 18 months, 24 months and 30 months after the birth of the child.

RESULTS

The decreased incidence rates of all-cause hospitalized pneumonia were observed at the four points in the PCV13 vaccinated group compared to the unvaccinated group, which were significant at the points of 12 months (0.42 % vs. 0.72 %, P = 0.001), 18 months (0.90 % vs. 1.26 %, P = 0.002) and 24 months (1.37 % vs. 1.65 %, P = 0.046). The VE of PCV13 against all-cause hospitalized pneumonia within 12 months was the highest as 41.9 % (95 % CI 19.6 %, 58.0 %), followed by 29.3 % (95 % CI 11.4 %, 43.5 %) within 18 months, 17.1 % (95 % CI 0.3 %, 31.1 %) within 24 months and it almost disappeared within 30 months. The VE of 4-dose vaccination within 18 months and 24 months were 39.9 % (95 % CI 20.3 %, 54.7 %) and 27.2 % (95 % CI 8.6 %, 42.0 %), respectively. The median hospitalization cost of the children in the vaccinated group was higher at the four points but without significance.

CONCLUSIONS

PCV13 had a certain protective effect on all-cause hospitalized pneumonia, and the booster immunization strategy had the best protective effect with great public health significance to enter the immunization program.

Prediction of post-PCV13 pneumococcal evolution using invasive disease data enhanced by inverse-invasiveness weighting

Background

After introduction of pneumococcal conjugate vaccines (PCVs), serotype replacement occurred in the population of Streptococcus pneumoniae. Predicting which pneumococcal clones and serotypes will become more common in carriage after vaccination can enhance vaccine design and public health interventions, while also improving our understanding of pneumococcal evolution. We sought to use invasive disease data to assess how well negative frequency-dependent selection (NFDS) models could explain pneumococcal carriage population evolution in the post-PCV13 epoch by weighting invasive data to approximate strain proportions in the carriage population.

Methods

Invasive pneumococcal isolates were collected and sequenced during 1998-2018 by the Active Bacterial Core surveillance (ABCs) from the Centers for Disease Control and Prevention (CDC). To predict the post-PCV13 population dynamics in the carriage population using a NFDS model, all genomic data were processed under a bioinformatic pipeline of assembly, annotation, and pangenome analysis to define genetically similar sequence clusters (i.e., strains) and a set of accessory genes present in 5% to 95% of the isolates. The NFDS model predicted the strain proportion by calculating the post-vaccine strain composition in the weighted invasive disease population that would best match pre-vaccine accessory gene frequencies. To overcome the biases of invasive disease data, serotype-specific inverse-invasiveness weights were defined as the ratio of the proportion of the serotype in the carriage data to the proportion in the invasive data, using data from 1998-2001 in the United States, before conjugate vaccine introduction. The weights were applied to adjust both the observed strain proportion and the accessory gene frequencies.

Results

Inverse-invasiveness weighting increased the correlation of accessory gene frequencies between invasive and carriage data with reduced residuals in linear or logit scale for pre-vaccine, post-PCV7, and post-PCV13. Similarly, weighting increased the correlation of accessory gene frequencies between different time periods in the invasive data. By weighting the invasive data, we were able to use the NFDS model to predict strain proportions in the carriage population in the post-PCV13 epoch, with the adjusted R-squared between predicted and observed strain proportions increasing from 0.176 to 0.544 after weighting.

Conclusions

The weighting system adjusted the invasive disease surveillance data to better represent the carriage population of S. pneumoniae. The NFDS mechanism predicted the strain proportions in the projected carriage population as estimated from the weighted invasive disease frequencies in the post-PCV13 epoch. Our methods enrich the value of genomic sequences from invasive disease surveillance, which is readily available, easy to collect, and of direct interest to public health.

Effectiveness of 13-valent pneumococcal conjugate vaccine on all-cause pneumonia in children under 5 years in Shanghai, China: An observational study

BACKGROUND

Streptococcus pneumoniae (Spn) is a common respiratory pathogen and the main cause of bacterial pneumonia, meningitis, and bacteremia, acute otitis media. Imported 13-valent pneumococcal conjugate vaccine (PCV13) was licensed in China and introduced in Shanghai in 2017. We aim to describe PCV13 vaccination trends and pneumonia incidence of children under 5 from 2017 to 2020, then estimate the effectiveness of PCV13 against community-acquired pneumonia (CAP) in children under 5 in Shanghai, China.

METHODS

By calculating propensity scores with logistic regression, a comparison group was formed by frequency matching one unvaccinated child to one vaccinated child. For matching, we used the nearest-neighbor matching algorithm and exact matching, and then created distinct matched analysis sets for two cohorts. A Kaplan-Meier analysis was conducted to measure the cumulative incidence of all-cause pneumonia in both groups and used the log-rank test to assess the differences between the two cumulative incidence curves. Cox proportional hazards regression was used to compare the adjusted hazard ratios (HR) of differences in all-cause pneumonia between the two groups.

RESULTS

Children received three or more doses PCV13 accounted for 85.7% of all vaccinated children. The incidence of pneumonia in Shanghai's Songjiang district decreased rapidly from 2017, when PCV13 vaccination presented an overall increasing trend. The estimated vaccine effectiveness against visits for all-cause pneumonia was 19% (95% CI: 3 to 32) after the first dose in children vaccinated with at least one dose of PCV13. The protective effectiveness of PCV13 was found to be higher for hospitalized pneumonia (30%, 95% CI: 5% to 49%) than for outpatient pneumonia (19%, 95% CI: 4% to 32%).

CONCLUSIONS

PCV13 vaccination among children aged 0-5 years substantially reduced the incidence of all-cause pneumonia. Direct immunization of children under 5 years is an effective strategy to combat outpatient pneumonia, and hospitalized pneumonia.

Effectiveness of thirteen-valent pneumococcal conjugate vaccine to prevent serotype 3 invasive pneumococcal disease in Quebec in children, Canada

In the province of Quebec, Canada, a 2 + 1 dose pneumococcal conjugate vaccine (PCV) program for children was implemented in 2004. PCV7 was replaced by PCV10 in 2009, by PCV13 in 2011 and by PCV10 in 2018, without catch-up in all instances. The objective was to estimate PCV13 effectiveness to prevent serotype 3 invasive pneumococcal disease in children aged less than 5 years, using 2010-2018 mandatory notification and laboratory surveillance data, an indirect cohort design and multivariate logistic regression models. A total of 29 cases of serotype 3 and 290 non-vaccine serotype cases as controls were analysed. Overall vaccine effectiveness (≥1 dose) was estimated at 59% [-39% to 88%]. During the first year after the last dose effectivness was 88% [47% to 97%] whereas no protection was observed thereafter. There was no trend towards increased effectiveness with the number of doses. PCV13 protection against serotype 3 IPD seems to be short-lived.

Estimating the Cost-Effectiveness of Switching to Higher-Valency Pediatric Pneumococcal Conjugate Vaccines in the United Kingdom

Currently, the 13-valent pneumococcal conjugate vaccine (PCV13) is administered under a 1+1 (1 primary dose) pediatric schedule in the United Kingdom (UK). Higher-valency PCVs, 15-valent PCV (PCV15), or 20-valent PCV (PCV20) might be considered to expand serotype coverage. We evaluated the cost-effectiveness of PCV20 or PCV15 using either a 2+1 (2 primary doses) or 1+1 schedule for pediatric immunization in the UK. Using a dynamic transmission model, we simulated future disease incidence and costs under PCV13 1+1, PCV20 2+1, PCV20 1+1, PCV15 2+1, and PCV15 1+1 schedules from the UK National Health Service perspective. We prospectively estimated disease cases, direct costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio. Scenario analyses were performed to estimate the impact of model assumptions and parameter uncertainty. Over a five-year period, PCV20 2+1 averted the most disease cases and gained the most additional QALYs. PCV20 2+1 and 1+1 were dominant (cost-saving and more QALYs gained) compared with PCV15 (2+1 or 1+1) and PCV13 1+1. PCV20 2+1 was cost-effective (GBP 8110/QALY) compared with PCV20 1+1. PCV20 was found cost-saving compared with PCV13 1+1, and PCV20 2+1 was cost-effective compared with PCV20 1+1. Policymakers should consider the reduction in disease cases with PCV20, which may offset vaccination costs.

Coverage of 13-Valent Pneumococcal Conjugate Vaccine Among Children 0-15 Months of Age - 9 Provinces, China, 2019-2021

What is already known on this topic?

Limited data exist regarding the coverage of the 13-valent pneumococcal conjugate vaccine (PCV13) in China. A lack of official statistics, coupled with an insufficient body of published literature, hinders the accurate depiction of the current situation.

What is added by this report?

This study investigated the utilization of PCV13 and estimated its coverage in nine provinces across eastern, central, and western China between 2019 and 2021. Despite an annual increase in PCV13 usage during this period, the overall coverage remained suboptimal.

What are the implications for public health practice?

Consideration should be given to incorporating vaccines into the Expanded Program of Immunization, reducing vaccine prices, and addressing the vaccination coverage gap between eastern and western regions when there is an adequate supply of PCV13, particularly with domestic vaccines.

Pneumococcal carriage following PCV13 delivered as one primary and one booster dose (1 + 1) compared to two primary doses and a booster (2 + 1) in UK infants

In January 2020 the UK changed from a 2 + 1 schedule for 13-valent pneumococcal conjugate vaccine (PCV13) to a 1 + 1 schedule (doses at 3 and 12 months) based on a randomized immunogenicity trial comparing the two schedules. Carriage prevalence measured at the time of booster and 6 months later in 191 of the 213 study infants was 57 % (109/191) and 60 % (114/190) respectively. There were eight episodes of vaccine-type (VT) or vaccine-related 6C carriage in the 2 + 1 and six in the 1 + 1 group; ≥4-fold rises in serotype-specific IgG in 71 children with paired post-booster and follow up blood samples at 21-33 months of age were found in 20 % (7/35) of the 2 + 1 and 15 % (6/41) of the 1 + 1 group. VTs identified in carriage and inferred from serology were similar comprising 3, 19A and 19F. Dropping a priming dose from the 2 + 1 PCV 13 schedule did not increase VT carriage in the study cohort. Ongoing population level carriage studies will be important to confirm this.

Mathematical modeling of pneumococcal transmission dynamics in response to PCV13 infant vaccination in Germany predicts increasing IPD burden due to serotypes included in next-generation PCVs

INTRODUCTION

Two next-generation pneumococcal conjugate vaccines (PCVs), a 15- and a 20-valent PCV (PCV15 and PCV20), have recently been licensed for use in adults, and PCV15 has also been licensed in children. We developed a dynamic transmission model specific for Germany, with the aim to predict carriage prevalence and invasive pneumococcal disease (IPD) burden for serotypes included in these vaccines.

METHODS

The model allows to follow serotype distributions longitudinally both in the absence and presence of PCV vaccinations. We considered eight age cohorts and seven serotype groups according to the composition of different pneumococcal vaccines. This comprises the additional serotypes contained in PCV15 and PCV20 but not in PCV13.

RESULTS

The model predicted that by continuing the current vaccine policy (standard vaccination with PCV13 in children and with PPSV23 in adults) until 2031, IPD case counts due to any serotype in children <2 years of age will remain unchanged. There will be a continuous decrease of IPD cases in adults aged 16-59y, but a 20% increase in adults ≥60y. Furthermore, there will be a steady decrease of the proportion of carriage and IPD due to serotypes included in PCV7 and PCV13 over the model horizon and a steady rise of non-PCV13 serotypes in carriage and IPD. The highest increase for both pneumococcal carriage and absolute IPD case counts was predicted for serotypes 22F and 33F (included in both PCV15 and PCV20) and serotypes 8, 10A, 11A, 12F, and 15B (included in PCV20 only), particularly in older adults. Between 2022 and 2031, serotypes included in PCV20 only are expected to cause 19.7-25.3% of IPD cases in adults ≥60y.

CONCLUSIONS

We conclude that introduction of next-generation PCVs for adults may prevent a substantial and increasing proportion of adult IPDs, with PCV20 having the potential to provide the broadest protection against pneumococcal disease.

Immunogenicity and safety of a 10-valent pneumococcal conjugate vaccine administered as a 2 + 1 schedule to healthy infants in The Gambia: a single-centre, double-blind, active-controlled, randomised, phase 3 trial

BACKGROUND

Three pneumococcal conjugate vaccines (PCVs) are currently licensed and WHO prequalified for supply by UN agencies. Here, we aimed to investigate the safety and immunogenicity of SIIPL-PCV compared with PHiD-CV and PCV13, when administered to infants according to a 2 + 1 schedule.

METHODS

This single-centre, double-blind, active-controlled, randomised, phase 3 trial was done in Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine clinical trial facilities within two government health centres in the western region of The Gambia. Healthy, PCV-naive infants aged 6-8 weeks were enrolled if they weighed at least 3·5 kg and had no clinically significant health complaints, as determined by history and clinical examination. Eligible infants were randomly assigned (1:1:1) to receive either SIIPL-PCV, PHiD-CV, or PCV13 using permuted blocks of variable size. Parents and the trial staff assessing all study outcomes were masked to vaccine group. The first PCV vaccine was given with other routine Expanded Programme on Immunization vaccines when infants were aged 6-8 weeks (visit 1). At visit 2, routine vaccines alone (without a PCV) were administered. At visit 3, the second dose of the PCV was administered alongside other routine vaccines. At visit 4, a blood sample was collected. Visits 1-4 took place at intervals of 4 weeks. The booster PCV was administered at age 9-18 months (visit 5), with final follow-up 4 weeks after the booster (visit 6). The primary immunogenicity outcome compared the serotype-specific IgG geometric mean concentrations (GMCs) generated by SIIPL-PCV with those generated by PHiD-CV and PCV13, 4 weeks after the booster. We used descriptive 95% CIs without adjustment for multiplicity. Immunogenicity analyses were done in the per protocol population (defined as all children who received all the assigned study vaccines, who had an immunogenicity measurement available, and who had no protocol deviations that might interfere with the immunogenicity assessment). This trial was registered with the Pan African Clinical Trials Registry, PACTR201907754270299, and ClinicalTrials.gov, NCT03896477.

FINDINGS

Between July 18 and Nov 14, 2019, 745 infants were assessed for study eligibility. Of these, 85 infants (11%) were ineligible and 660 (89%) were enrolled and randomly assigned to receive SIIPL-PCV (n=220), PHiD-CV (n=220), or PCV13 (n=220). 602 infants (91%) were included in the per protocol immunogenicity population. The median age at vaccination was 46 days (range 42-56). 342 infants (52%) were female and 318 (48%) were male. Post-booster serotype-specific IgG GMCs generated by SIIPL-PCV ranged from 1·54 μg/mL (95% CI 1·38-1·73) for serotype 5 to 12·46 μg/mL (11·07-14·01) for serotype 6B. Post-booster GMCs against shared serotypes generated by PHiD-CV ranged from 0·80 μg/mL (0·72-0·88) for serotype 5 to 17·31 μg/mL (14·83-20·20) for serotype 19F. Post-booster GMCs generated by PCV13 ranged from 2·04 μg/mL (1·86-2·24) for serotype 5 to 15·54 μg/mL (13·71-17·60) for serotype 6B. Post-booster IgG GMCs generated by SIIPL-PCV were higher than those generated by PHiD-CV for seven of the eight shared serotypes (1, 5, 6B, 7F, 9V, 14, and 23F). The GMC generated by serotype 19F was higher after PHiD-CV. The SIIPL-PCV to PHiD-CV GMC ratios for shared serotypes ranged from 0·64 (95% CI 0·52-0·79) for serotype 19F to 2·91 (2·47-3·44) for serotype 1. The serotype 1 GMC generated by SIIPL-PCV was higher than that generated by PCV13, whereas serotype 5, 6A, 19A, and 19F GMCs were higher after PCV13. The SIIPL-PCV to PCV13 GMC ratios ranged from 0·72 (0·60-0·87) for serotype 19A to 1·44 (1·23-1·69) for serotype 1.

INTERPRETATION

SIIPL-PCV was safe and immunogenic when given to infants in The Gambia according to a 2 + 1 schedule. This PCV is expected to provide similar protection against invasive and mucosal pneumococcal disease to the protection provided by PCV13 and PHiD-CV, for which effectiveness data are available. Generating post-implementation data on the impact of SIIPL-PCV on pneumococcal disease endpoints remains important.

FUNDING

Bill & Melinda Gates Foundation.

Effectiveness of 10 and 13-valent pneumococcal conjugate vaccines against invasive pneumococcal disease in European children: SpIDnet observational multicentre study

BACKGROUND

Pneumococcal conjugate vaccines covering 10 (PCV10) and 13 (PCV13) serotypes have been introduced in the infant immunization schedule of most European countries in 2010-11. To provide additional real-life data, we measured the effectiveness of PCV10 and PCV13 against invasive pneumococcal disease (IPD) in children of 12 European sites (SpIDnet).

METHODS

We compared the vaccination status of PCV10 and PCV13 serotype IPD (cases) to that of nonPCV13 serotype IPD (controls) reported in 2012-2018. We calculated pooled effectiveness as (1-vaccination odds ratio)*100, and measured effectiveness over time since booster dose.

RESULTS

The PCV13 and PCV10 studies included 2522 IPD cases from ten sites and 486 cases from four sites, respectively. The effectiveness of ≥ 1 PCV13 dose was 84.2% (95 %CI: 79.0-88.1) against PCV13 serotypes (n = 2353) and decreased from 93.1% (87.8-96.1) < 12 months to 85.1% (72.0-92.1) ≥ 24 months after booster dose. PCV13 effectiveness of ≥ 1 dose was 84.7% (55.7-94.7) against fatal PCV13 IPD, 64.5% (43.7-77.6), 83.2% (73.7-89.3) and 85.1% (67.6-93.1) against top serotypes 3, 19A and 1, respectively, and 85.4% (62.3-94.4) against 6C. Serotype 3 and 19A effectiveness declined more rapidly. PCV10 effectiveness of ≥ 1 dose was 84.8% (69.4-92.5) against PCV10 serotypes (n = 370), 27.2% (-187.6 to 81.6) and 85.3% (35.2-96.7) against top serotypes 1 and 7F, 32.5% (-28.3 to 64.5) and -14.4% (-526.5 to 79.1) against vaccine-related serotypes 19A and 6C, respectively.

CONCLUSIONS

PCV10 and PCV13 provide similar protection against IPD due to the respective vaccine serotype groups but serotype-specific effectiveness varies by serotype and vaccine. PCV13 provided individual protection against serotype 3 and vaccine-related serotype 6C IPD. PCV10 effectiveness was not significant against vaccine-related serotypes 19A and 6C. PCV13 effectiveness declined with time after booster vaccination. This multinational study enabled measuring serotype-specific vaccine effectiveness with a precision rarely possible at the national level. Such large networks are crucial for the post-licensure evaluation of vaccines.

Impact of 13-Valent Pneumococcal Conjugate Vaccine on Invasive Pneumococcal Disease Among Adults With HIV-United States, 2008-2018

BACKGROUND

People with HIV (PWH) are at increased risk for invasive pneumococcal disease (IPD). Thirteen-valent pneumococcal conjugate vaccine (PCV13) was recommended for use in US children in 2010 and for PWH aged 19 years or older in 2012. We evaluated the population-level impact of PCV13 on IPD among PWH and non-PWH aged 19 years or older.

METHODS

We identified IPD cases from 2008 to 2018 through the Active Bacterial Core surveillance platform. We estimated IPD incidence using the National HIV Surveillance System and US Census Bureau data. We measured percent changes in IPD incidence from 2008 to 2009 to 2017-2018 by HIV status, age group, and vaccine serotype group, including serotypes in recently licensed 15-valent (PCV15) and 20-valent (PCV20) PCVs.

RESULTS

In 2008-2009 and 2017-2018, 8.4% (552/6548) and 8.0% (416/5169) of adult IPD cases were among PWH, respectively. Compared with non-PWH, a larger proportion of IPD cases among PWH were in adults aged 19-64 years (94.7%-97.4% vs. 56.0%-60.1%) and non-Hispanic Black people (62.5%-73.0% vs. 16.7%-19.2%). Overall and PCV13-type IPD incidence in PWH declined by 40.3% (95% confidence interval: -47.7 to -32.3) and 72.5% (95% confidence interval: -78.8 to -65.6), respectively. In 2017-2018, IPD incidence was 16.8 (overall) and 12.6 (PCV13 type) times higher in PWH compared with non-PWH; PCV13, PCV15/non-PCV13, and PCV20/non-PCV15 serotypes comprised 21.5%, 11.2%, and 16.5% of IPD in PWH, respectively.

CONCLUSIONS

Despite reductions post-PCV13 introduction, IPD incidence among PWH remained substantially higher than among non-PWH. Higher-valent PCVs provide opportunities to reduce remaining IPD burden in PWH.

Incidence, aetiology and serotype coverage for pneumococcal vaccines of community-acquired pneumonia in adults: a population-based prospective active surveillance study in Brazil

OBJECTIVES

To determine the incidence, aetiology and pneumococcal serotype distribution of community-acquired pneumonia (CAP) in Brazilian adults during a 2-year period.

DESIGN

Prospective population-based surveillance study.

SETTING

Patients from two emergency hospitals in Brazil were consecutively included in this study.

PARTICIPANTS

A total of 111 adults aged 50 years and older with radiographically-confirmed CAP requiring an emergency department visit were prospectively enrolled between January 2018 and January 2020.

MAIN OUTCOME MEASURES

Incidence rates of CAP were calculated according to age and pathogen. Pathogens were identified by conventional microbiological methods. Additionally, a novel, Luminex-based serotype specific urinary antigen detection assay was used to detect serotypes included in pneumococcal vaccines.

RESULTS

Mean age of participants was 64 years and 31% were aged ≥70 years. Aetiology was established in 61 (57%) patients; among identified cases, the most common pathogens were Streptococcus pneumoniae (42/61, 69%) and influenza (4/61, 7%). Among serotypes identified from the 42 cases of pneumococcal CAP, estimated coverage ranged by pneumococcal vaccine formulations from 47.6% (13-valent), 59.5% (20-valent, licenced in the USA only) and 71.4% (23-valent). In patients with CAP, 20-valent pneumococcal vaccine serotypes were identified 2.5 times more frequently than 10-valent pneumococcal vaccine serotypes (22.5% vs 9.0%). The incidence rate for CAP in adults aged ≥50 years was 20.1 per 10 000 person-years. In general, the incidence of CAP increased consistently with age, reaching 54.4 (95% CI 36.8 to -76.6) per 10 000 in adults 80 years or older.

CONCLUSIONS

We observed a high burden of pneumococcal CAP among adults in Brazil. Despite the routine immunisation of children and high-risk adults against pneumococcal disease in the Brazilian national vaccination programme, a persistent burden of pneumococcal CAP caused by vaccine serotypes remains in this population.

Serotype Replacement after Introduction of 10-Valent and 13-Valent Pneumococcal Conjugate Vaccines in 10 Countries, Europe

We evaluated invasive pneumococcal disease (IPD) during 8 years of infant pneumococcal conjugate vaccine (PCV) programs using 10-valent (PCV10) and 13-valent (PCV13) vaccines in 10 countries in Europe. IPD incidence declined during 2011-2014 but increased during 2015-2018 in all age groups. From the 7-valent PCV period to 2018, IPD incidence declined by 42% in children <5 years of age, 32% in persons 5-64 years of age, and 7% in persons >65 years of age; non-PCV13 serotype incidence increased by 111%, 63%, and 84%, respectively, for these groups. Trends were similar in countries using PCV13 or PCV10, despite different serotype distribution. In 2018, serotypes in the 15-valent and 20-valent PCVs represented one third of cases in children <5 years of age and two thirds of cases in persons >65 years of age. Non-PCV13 serotype increases reduced the overall effect of childhood PCV10/PCV13 programs on IPD. New vaccines providing broader serotype protection are needed.

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.

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.

National surveillance of antimicrobial susceptibilities to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics and serotype distribution of invasive Streptococcus pneumoniae isolates in adults: results from the Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART) programme in 2017-2020

Objectives

The aim of this study was to investigate the trends in serotypes and in vitro antimicrobial susceptibility of Streptococcus pneumoniae causing adult invasive pneumococcal disease (IPD) to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics from 2017–2020 following implementation of the 13-valent pneumococcal conjugate vaccine (PCV-13) and during the COVID-19 (coronavirus disease 2019) pandemic.

Methods

During the study period, 237 S. pneumoniae isolates were collected from non-duplicate patients, covering 15.0% of IPD cases in Taiwan. Antimicrobial susceptibility testing was performed using a Sensititre® system. A latex agglutination method (ImmuLex™ Pneumotest Kit) was used to determine serotypes.

Results

Susceptibility rates were high for vancomycin (100%), teicoplanin (100%) and linezolid (100%), followed by ceftaroline (non-meningitis) (98.3%), moxifloxacin (94.9%) and quinupristin/dalfopristin (89.9%). MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline and omadacycline were generally low. Non-vaccine serotype 23A was the leading cause of IPD across the adult age range. Isolates of serotype 15B were slightly fewer than those of PCV-13 serotypes in patients aged ≥65 years. The overall case fatality rate was 15.2% (36/237) but was especially high for non-PCV-13 serotype 15B (21.4%; 3/14). Vaccine coverage was 44.7% for PCV-13 and 49.4% for the 23-valent pneumococcal polysaccharide vaccine (PPSV-23), but was 57% for both PCV-13 and PPSV-23.

Conclusion

The incidence of IPD was stationary after PCV-13 introduction and only dramatically decreased in the COVID-19 pandemic in 2020. The MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline, omadacycline were generally low for S. pneumoniae causing adult IPD.

Stable Incidence of Invasive Pneumococcal Disease in Children in Northern France From 2014 Through 2018

BACKGROUND

The 13-valent pneumococcal conjugate vaccine (PCV13) has been recommended in France since June 2010. The aim of this study was to evaluate the trends in the incidence of invasive pneumococcal disease (IPD) resulting in hospitalization of children younger than 18 years of age, to identify the vaccination status of these patients and to analyze the serotypic evolution of the pneumococci involved in the various types of IPD.

METHODS

This multicenter retrospective study reviewed all admissions of children younger than 18 years of age for IPD from 2014 through 2018 in all hospitals with a pediatric or neonatal unit in northern France. Data completeness was obtained by matching 3 independent databases. The incidence of IPD resulting in hospitalization was calculated per age group. The clinical course and the vaccine and nonvaccine types were described overall and by the IPD type.

RESULTS

One hundred thirty cases of IPD were identified: 51 with bacteremia, 45 meningitis, 28 pneumonia or pleuropneumonia and 6 arthritis. The IPD incidence ranged from 2.4 to 3.0/100,000 in children under 18 years of age (95% confidence intervals, 1.4-3.3 and 1.9-4.1, respectively), and from 9.5 to 15.9/100,000 in children under 2 years of age, with no significant differences over time. Nonvaccine types were predominant (81%), mainly 24F, 23B and 10A. Vaccine serotype 3 was involved in 10 cases of IPD, 2 of which were in correctly vaccinated children. Two cases of IPD could have been prevented by vaccination. Neurologic sequelae affected 26% of these children (62% of those with meningitis). Six children died from IPD (5%).

CONCLUSION

The incidence of IPD resulting in hospitalization remained stable in northern France during the study period, with no significant increase in nonvaccine types. Further surveillance is needed to adjust the vaccination strategy if necessary.

Failures of 13-Valent Conjugated Pneumococcal Vaccine in Age-Appropriately Vaccinated Children 2-59 Months of Age, Spain

Vaccination with the 13-valent conjugated pneumococcal disease (PCV13) has reduced invasive pneumococcal disease (IPD), but there have been reports of vaccine failures. We performed a prospective study in children aged 2–59 months who received diagnoses of IPD during January 2012–June 2016 in 3 pediatric hospitals in Catalonia, Spain, a region with a PCV13 vaccination coverage of 63%. We analyzed patients who had been age-appropriately vaccinated but who developed IPD caused by PCV13 serotypes. We detected 24 vaccine failure cases. The serotypes involved were 3 (16 cases); 19A (5 cases); and 1, 6B, and 14 (1 case each). Cases were associated with children without underlying conditions, with complicated pneumonia (OR 6.65, 95% CI 1.91–23.21), and with diagnosis by PCR (OR 5.18, 95% CI 1.84–14.59). Vaccination coverage should be increased to reduce the circulation of vaccine serotypes. Continuous surveillance of cases of IPD using both culture and PCR to characterize vaccine failures is necessary.

Complications in community acquired pneumonia: magnitude of problem, risk factors, and management in pediatric age

Introduction: In the last decades, the large use of several effective vaccines has dramatically reduced the incidence of community acquired pneumonia (CAP) in infants and children. Moreover, the availability of new antibiotics effective against emerging resistant strains of bacteria has greatly improved the early and long-term prognosis of this disease.Areas covered: The aim of this manuscript is to evaluate the burden of complicated CAP in pediatric age and to discuss its appropriate management.Expert opinion: Complicated CAP remains a problem for children in industrialized and developing countries. A larger use of lung ultrasonography (US) as first diagnostic approach could significantly improve early identification of cases at higher risk of complications. Difficult to solve, is the problem of the use of an antibiotic therapy able to assure adequate control in all the CAP cases, including those at high risk of or with already established complications. All these findings reveal that control of the incidence of complicated CAP remains difficult and will not be significantly changed in the next few years. Any attempt to improve complicated CAP management must be made. Consensus documents on better definition of the use of corticosteroids, fibrinolytic agents, and interventional procedures (including surgery) can allow us to reach this goal.

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.

Invasive pneumococcal disease due to 22F and 33F in England: A tail of two serotypes

BACKGROUND

A 15-valent pneumococcal conjugate vaccine (PCV15) aims to protect against serotype 22F and 33F in addition to the serotypes within the 13-valent PCV (PCV13) which was introduced to the UK childhood immunisation programme in April 2010. Little is known about the specific epidemiology, clinical features or outcomes of invasive pneumococcal disease (IPD) due to these two serotypes.

METHODS

Public Health England (PHE) conducts enhanced IPD surveillance in England. Hospital laboratories routinely submit invasive pneumococcal isolates to PHE for serotyping and enhanced clinical information is collected through questionnaires sent to general practitioners. IPD due to serotypes 22F and 33F diagnosed during 2014/15-2018/19 were compared with IPD due to PCV13 serotypes and remaining serotypes.

RESULTS

In total, 25,415 isolates (93.4%) were serotyped and questionnaires were completed for 22,097 (86.9%) cases. Serotype 22F was responsible for 1,788 (7.0%) and serotype 33F for 893 (3.5%) cases compared to 19.9% (n = 5,047) for PCV13 and 69.6% (n = 17,687) for the remaining serotypes. IPD incidence increased for both serotypes since 2005/06, especially in older adults, but plateaued after PCV13 introduction. Comorbidity prevalence was 68.7% (n = 1,037) for serotype 22F and 67.2% (n = 505) for serotype 33F, with invasive pneumonia being the most common clinical presentation 1,067/1,482; 72.0%, and 514/755; 68.1%, respectively. There were 3,617 deaths within 30 days of disease onset, including 236 (CFR, 15.4%) among 22F, 128 (CFR, 16.5%) among 33F and 21.3% (925/4,350) among PCV13-type IPD cases. When compared with PCV13-type IPD, serotype 22F (aOR 0.58, 95%CI 0.49-0.68, p < 0.001) and 33F (aOR 0.73, 95%CI 0.59-0.91, p = 0.004) were independently associated with lower odds of death. The major circulating sequence types (STs) in 22F (ST 433, ST698) and 33F (ST717, ST100, ST673) were not associated with an increased risk of death compared to the other STs.

CONCLUSIONS

Serotype 22F and 33F-type IPD are associated with a lower risk of death compared to PCV13-type, with those presenting with septicaemia more likely to have a fatal outcome compared to pneumonia. PCV15 has the potential to prevent up to an additional 10% of IPD cases in England.

Immunogenicity following revaccination or sequential vaccination with 23-valent pneumococcal polysaccharide vaccine (PPSV23) in older adults and those at increased risk of pneumococcal disease: a review of the literature

Introduction: Immunogenicity studies evaluating sequential administration of pneumococcal conjugate vaccine (PCV) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) or revaccination with PPSV23 have raised concerns that PPSV23 may not elicit higher antibody levels than those measured following PCV or first PPSV23 dose.Areas covered: Recent literature was evaluated for evidence of blunted immune response (hyporesponsiveness), focusing on studies using adequate intervals between doses in accordance with vaccination recommendations. In eight of nine studies that evaluated revaccination with PPSV23 at an interval of ≥5 years after the previous dose, immunoglobulin G geometric mean concentrations and/or opsonophagocytic assay geometric mean titers for most serotypes increased from pre- to post-repeat vaccination and were comparable between repeat and primary vaccination groups post-vaccination. In seven studies in which PPSV23 was administered after PCVs (8 weeks to 1 year apart), responses to PPSV23 were comparable to those seen after initial PCV dose for shared vaccine serotypes. Studies in which PCVs were administered after PPSV23 were not evaluated.Expert opinion: Published data suggest immune responses following repeat vaccination with PPSV23, or sequential PCV/PPSV23 vaccination, are robust, without evidence of hyporesponsiveness. PPSV23 vaccination of at-risk adults is essential to ensure broad protection against all 23 vaccine serotypes.

Impact of pneumococcal conjugate vaccine on invasive pneumococcal disease in children under 5 years of age in the Czech Republic

Introduction

The aim of this study is to analyse the impact of vaccination of infants with pneumococcal conjugate vaccine (PCV) on the incidence of invasive pneumococcal disease (IPD) in children under 5 years of age in the Czech Republic.

Material and methods

The present study includes all IPD cases reported in children aged 0–4 years within the surveillance program in 2007–2017. The impact of PCV is analysed for five categories of IPD: cases caused by all serotypes, cases caused by PCV7 serotypes (4, 6B, 9V, 14, 18C, 19F, and 23F), cases caused by three additional PCV10 serotypes (1, 5, and 7F), cases caused by three additional PCV13 serotypes (3, 6A, and 19A), and cases caused by non-PCV serotypes. To assess the impact of PCV, the study period was divided into the pre-vaccination period 2007–2008 and post-vaccination period 2009–2017, which was divided into three three-year parts: 2009–2011, 2012–2014, and 2015–2017. Analysis of differences between periods was based on the Poisson regression model where the population numbers were handled as an offset.

Results

The annual incidence of IPD in children under 5 years of age caused by all serotypes has had a downward trend since 2007: it dropped from 8.52/100 000 in 2007 to 2.67/100 000 in 2017, with slight increases in 2010 and 2013. All three post-vaccination periods show significantly lower (p<0.001) incidences in comparison to the pre-vaccination period, but they do not statistically significantly differ from each other.

Conclusions

IPD surveillance data in the Czech Republic show that after the introduction of PCV vaccination of infants, there has been a significant decrease in the IPD incidence of children under 5 years of age. Continued IPD surveillance is essential to monitor for possible post-vaccination serotype replacement.

Exploring the evidence behind the comparable impact of the pneumococcal conjugate vaccines PHiD-CV and PCV13 on overall pneumococcal disease

The worldwide implementation of pneumococcal conjugate vaccines (PCVs) in children has reduced the overall pneumococcal disease burden. Two PCVs are widely available for infant vaccination: the pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) and the 13-valent PCV (PCV13). While these PCVs differ in serotype composition (PCV13 includes polysaccharides of serotypes 3, 6A and 19A; PHiD-CV does not), their impact on the overall pneumococcal disease burden in children is comparable. This commentary summarizes the evidence of comparability between PHiD-CV and PCV13 and explores why differences in serotype composition may not necessarily translate into a differential clinical impact. Both vaccines confer similarly high protection against disease caused by vaccine serotypes and lead to a partial replacement by non-vaccine serotypes. PHiD-CV does not protect against serotype 3 disease (not included in the vaccine) and PCV13’s effect on this serotype has been inconsistent. PHiD-CV provides some cross-protection against disease caused by vaccine-related serotype 19A but neither vaccine has fully controlled 19A disease. While protection against 19A is higher for PCV13 than PHiD-CV, replacement by non-PCV13 serotypes in settings with a PCV13 program appears to compensate for this difference. This results in a similar residual overall disease burden with both vaccines.

What is the context?

The pneumococcus bacterium can cause infections of the meninges, blood, lung, middle ear and sinuses.

Two vaccins, Synflorix (GSK) and Prevnar 13 (Pfizer Inc.), are widely used to protect young children against these infections.

The vaccines’ compositions differ: Synflorix includes antigens from 10 pneumococcus strains (or “serotypes”) and Prevnar 13 from 13 serotypes.

However, both have a similar effect on the total pneumococcal disease burden in children.

What does this commentary highlight?

This commentary summarizes the evidence beihnd the two vaccines’ comparable impact on pneumococcal disase.

It also looks at why the vaccines have a similar effect on the total pneumococcal disease burden despite their different compositions.

What is the impact on current thinking?

Given that Synflorix and Prevnar 13 have a comparable impact on pneumococcal disease, a country’s choice between the two vaccines will depend on vaccine supply, cost, logistical factors (e.g., transport, storage, training requirements of health workers) and the local pneumococcal epidemiology.

Health and economic burden of invasive pneumococcal disease associated with 15-valent pneumococcal conjugate vaccine serotypes in children across eight European countries

AIMS

V114, a 15-valent pneumococcal conjugate vaccine (PCV15) currently approved in adults in the US, contains the 13 S. pneumoniae serotypes in PCV13 and two additional serotypes, 22 F and 33 F, which are important contributors to residual PD. This study quantified the health and economic burden of pediatric invasive pneumococcal disease (IPD) associated with V114 serotypes in eight countries in Europe.

MATERIALS AND METHODS

A Markov model estimated V114-type IPD cases and costs in hypothetical unvaccinated birth cohorts from Denmark, France, Germany, Italy, Norway, Spain, Switzerland, and the UK over 20 years. Inputs were obtained from published literature. IPD cases and costs were calculated for three time periods using time-specific epidemiological data: (a) pre-PCV7; (b) pre-PCV13; and (c) post-PCV13. Costs were estimated from a societal perspective (2018 Euros) and discounted at 3%.

RESULTS

The model estimated that 4,649 IPD cases in the pre-PCV7 period, 3,248 cases in the pre-PCV13 period, and 958 cases in the post-PCV13 period were attributable to V114 serotypes. Total discounted costs associated with V114 serotypes were €109.1 million (pre-PCV7 period), €65.7 million (pre-PCV13 period), and €18.7 million (post-PCV13 period).

LIMITATIONS

Post-meningitis sequelae, acute otitis media, and non-bacteremic pneumonia were not considered. Direct non-medical costs were not included. Conclusions on effectiveness of V114 or added value over existing infant vaccination programs cannot be drawn.

CONCLUSIONS

IPD cases and costs were estimated in hypothetical birth cohorts in eight European countries followed for 20 years during three time periods. Serotypes included in V114 were associated with significant morbidity and costs in pre-PCV7, pre-PCV13, and post-PCV13 periods. Future pediatric pneumococcal vaccines should maintain protection against serotypes in licensed vaccines while extending coverage to additional serotypes to ensure reductions in IPD burden are maintained.

Health and economic burden associated with 15-valent pneumococcal conjugate vaccine serotypes in children in the United States

AIMS

V114 is an investigational 15-valent pneumococcal conjugate vaccine (PCV) containing the 13 Streptococcus pneumoniae serotypes in 13-valent PCV (PCV13) plus two additional serotypes. This study quantified the health and economic burden of invasive pneumococcal disease (IPD) and acute otitis media (AOM) caused by V114 types among children in the United States.

MATERIALS AND METHODS

A Markov model estimated the number of V114-type IPD and AOM cases and costs in a hypothetical, unvaccinated US birth cohort over 20 years. Three time periods were analyzed using time-specific epidemiological data to determine the number of IPD and AOM cases associated with all 15 serotypes in V114. The time periods were: (1) pre-PCV7 (1999); (2) pre-PCV13 (2009); (3) post-PCV13 (2017). Costs were estimated from a societal perspective (2018 US dollars) and discounted at 3%.

RESULTS

The model estimated 18,983 IPD cases and 5.4 million AOM cases associated with V114 serotypes pre-PCV7, 4,697 IPD cases and 3.0 million AOM cases pre-PCV13, and 948 IPD cases and 0.2 million AOM cases post-PCV13. Total discounted costs associated with V114 serotypes were $1.7 billion pre-PCV7, $730 million pre-PCV13, and $75 million US dollars post-PCV13.

LIMITATIONS

Post-meningitis sequelae, cases of non-bacteremic pneumonia, and direct non-medical costs were not included.

CONCLUSIONS

IPD and AOM cases and costs were estimated in a hypothetical US birth cohort followed for 20 years at three time periods. In all three periods, the serotypes targeted by V114 contributed to significant morbidity and costs. New pediatric pneumococcal vaccines must continue to retain serotypes in licensed vaccines to maintain disease reduction while extending coverage to non-vaccine serotypes.

Impact and effectiveness of the 10-valent pneumococcal conjugate vaccine on invasive pneumococcal disease among children under 5 years of age in the Netherlands

BACKGROUND

In 2011, the 7-valent pneumococcal conjugate vaccine (PCV7) was replaced by the 10-valent vaccine (PCV10) in the Netherlands. We report on impact and effectiveness against invasive pneumococcal disease (IPD) in children aged under 5 years by switching from PCV7 to PCV10.

METHOD

We included IPD cases between 2004 and 2019 in children aged < 5 years reported via the national surveillance system. To assess the impact of the PCV10 vaccination program we compared IPD incidence 6-8 years after PCV10 introduction (2017-2019) to the two years just before the switch to PCV10 (2009-2011). We estimated vaccine effectiveness (VE) using the indirect cohort method, comparing vaccination status (at least two vaccine doses) in IPD-cases caused by PCV10 serotypes (cases) to non-PCV10 IPD cases (controls), in children eligible for PCV10.

RESULTS

The overall incidence decreased from 8.7 (n = 162) in 2009-2011 to 7.3 per 100.000 (n = 127) in 2017-2019 (Incidence rate ratio (IRR) 0.83, 95%CI: 0.66; 1.05). IPD caused by the additional serotypes included in PCV10 declined by 93% (IRR 0.07, 95%CI: 0.02; 0.23). Incidence of non-PCV10 IPD showed a non-significant increase (IRR 1.25, 95%CI: 0.96; 1.63). Among 231 IPD-cases eligible for PCV10, the overall VE was 91% (95%CI: 67; 97) and did not differ by sex or age at diagnosis. Effectiveness against non-PCV10 serotype 19A IPD was non-significant with an estimate of 28% (95%CI:-179; 81).

CONCLUSION

PCV10 is highly effective in protecting against IPD in Dutch children under 5 years with limited serotype replacement after switching from PCV7 to PCV10. We found no evidence for significant cross-protection of PCV10 against 19A serotype IPD.

Summary of evidence to reduce the two-dose infant priming schedule to a single dose of the 13-valent pneumococcal conjugate vaccine in the national immunisation programme in the UK

Pneumococcal conjugate vaccines (PCVs) are highly effective in preventing invasive and non-invasive pneumococcal infections in all age groups through a combination of direct and indirect protection. In many industrialised countries with established PCV programmes, the maximum benefit of the PCV programme has already been achieved, with most cases now due to non-PCV serotypes. On Jan 1, 2020, the UK changed its childhood pneumococcal immunisation programme from a two-dose infant priming schedule with the 13-valent PCV at 8 and 16 weeks after birth, to a single priming dose at 12 weeks after birth, while retaining the 12-month booster. This decision was made after reviewing the evidence from surveillance data, clinical trials, epidemiological analyses, vaccine effectiveness estimates, and modelling studies to support the reduced schedule. In this Review, we summarise the epidemiology of pneumococcal disease in the UK, the evidence supporting the decision to implement a reduced schedule, and the national and global implications of the proposed schedule.

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

Pneumococcal disease is a substantial contributor to illness and death in young children globally. The introduction of 7-valent pneumococcal conjugate vaccine (PCV7) in 2000 had a significant impact in preventing pneumococcal disease in both vaccinated children and unvaccinated individuals (through herd effect). A higher valent PCV13 replaced PCV7 in late 2009. This analysis was undertaken to assess how many cases and deaths have been averted over the last decade since PCV13 introduction. A model estimated the number of infants vaccinated annually with PCV13, as well as the number of cases and deaths of invasive pneumococcal disease, pneumococcal pneumonia, and acute otitis media cases averted. PCV13 vaccination was estimated to have prevented 175.2 million cases of all pneumococcal diseases and 624,904 deaths globally between 2010 and 2019. These results demonstrate the substantial public health impact of PCV13 and highlight the importance of increasing the global reach of PCV programs.

Pneumococcal conjugate serotype distribution and predominating role of serotype 3 in German adults with community-acquired pneumonia

INTRODUCTION

Implementation of the 7-valent pneumococcal conjugate vaccine (PCV7) in infant vaccination programs has substantially reduced the burden of PCV7 serotypes also in adult community-acquired pneumonia (CAP). Currently, it is unclear, if this extensive herd protection effect can be extrapolated to the additional 6 serotypes included in the 13-valent pneumococcal conjugate vaccine (PCV13), which replaced PCV7 in Germany in 2010.

OBJECTIVES

We investigated changing trends for PCV13 serotypes in adult CAP patients between three to seven years after implementation of PCV13 infant immunization in Germany.

METHODS

Between December 2012 and January 2017, urine samples from German adult patients with radiologically confirmed CAP were prospectively collected by the multi-center cohort study CAPNETZ and analyzed by the serotype-specific multiplex urinary antigen detection assay (SSUAD) allowing for the detection of PCV13 serotypes.

RESULTS

PCV13 serotypes were found in 59 of 796 (7.4%) patients with all-cause CAP, most prevalent was serotype 3 (30 of 59 patients, 50.8%). All patients with serotype 3-CAP were admitted to hospital and the majority required oxygen at admission (83.3% of patients with serotype 3-CAP versus 50.9% of patients with pneumococcal CAP by other serotypes, p = 0.005). Compared to SSUAD testing, conventional microbiological workup missed 27 of 30 (90.0%) serotype 3-CAP cases. We could not observe a time trend in the proportions of PCV13 serotypes and serotype 3 in all-cause CAP between 2013 and 2016 (OR trend per year 0.84, 95% CI 0.64-1.11 for PCV13 serotypes and OR trend per year 0.95, 95% CI 0.70-1.28 for serotype 3).

CONCLUSIONS

Conventional methods underestimate serotype 3-CAP that can cause severe disease. Changes in overall PCV13 coverage were not detected during the years 2013 to 2016, mostly driven by a high proportion of serotype 3.

Evolution of Streptococcus pneumoniae Serotype 3 in England and Wales: A Major Vaccine Evader

Despite its inclusion in pneumococcal conjugate vaccine 13 (PCV13), Streptococcus pneumoniae serotype 3 remains a major cause of invasive pneumococcal disease in England and Wales. Previous studies have indicated that there are distinct lineages within serotype 3 clonal complex 180 and the clade distributions have shifted in recent years with the emergence of clade II. We undertook whole genome sequencing and genomic analysis of 616 serotype 3 isolates from England and Wales between 2003 and 2018, including invasive and carriage isolates. Our investigations showed that clade II has expanded since 2014 and now represents 50% of serotype 3 invasive pneumococcal disease (IPD) isolates in England and Wales. Genomic analysis of antibiotic resistance and protein antigen genes showed that distinct profiles are present within the clades which could account for the recent emergence of this clade. This investigation highlights the importance and utility of routine whole genome sequencing and its ability to identify new and emerging variation at the single nucleotide level which informs surveillance and will impact future vaccine development.

The Genomics of Streptococcus Pneumoniae Carriage Isolates from UK Children and Their Household Contacts, Pre-PCV7 to Post-PCV13

We used whole genome sequencing (WGS) analysis to investigate the population structure of 877 Streptococcus pneumoniae isolates from five carriage studies from 2002 (N = 346), 2010 (N = 127), 2013 (N = 153), 2016 (N = 187) and 2018 (N = 64) in UK households which covers the period pre-PCV7 to post-PCV13 implementation. The genomic lineages seen in the population were determined using multi-locus sequence typing (MLST) and PopPUNK (Population Partitioning Using Nucleotide K-mers) which was used for local and global comparisons. A Roary core genome alignment of all the carriage genomes was used to investigate phylogenetic relationships between the lineages. The results showed an influx of previously undetected sequence types after vaccination associated with non-vaccine serotypes. A small number of lineages persisted throughout, associated with both non-vaccine and vaccine types (such as ST199), or that could be an example of serotype switching from vaccine to non-vaccine types (ST177). Serotype 3 persisted throughout the study years, represented by ST180 and Global Pneumococcal Sequencing Cluster (GPSC) 12; the local PopPUNK analysis and core genome maximum likelihood phylogeny separated them into two clades, one of which is only seen in later study years. The genomic data showed that serotype replacement in the carriage studies was mostly due to a change in genotype as well as serotype, but that some important genetic lineages, previously associated with vaccine types, persisted.