Effectiveness of the 23-valent pneumococcal polysaccharide vaccine against vaccine serotype pneumococcal pneumonia in adults: A case-control test-negative design study

The impact and cost-effectiveness of pneumococcal immunisation strategies for the elderly in England

Pneumococcal disease, presenting as invasive pneumococcal disease (IPD) or community-acquired pneumonia (CAP) is an important cause of illness and hospitalisation in the elderly. To reduce pneumococcal burden, since 2003, 65-year-olds in England have been offered a 23-valent pneumococcal polysaccharide vaccine (PPV23). This study compares the impact and cost-effectiveness (CE) of vaccination with the existing PPV23 vaccine to the new 15-and 20-valent pneumococcal conjugate vaccines (PCV15 and PCV20), targeting adults aged 65 or 75 years old. We developed a static Markov model for immunisation against pneumococcal disease, capturing different vaccine effectiveness and immunity waning assumptions, projecting the number of IPD/CAP cases averted over the thirty years following vaccination. Using an economic model and probabilistic sensitivity analysis we evaluated the CE of the different immunisation strategies at current vaccine list prices and the willingness-to-pay at a median threshold of £20,000/QALY and an uncertainty threshold of 90% of simulations below £30,000/QALY. PCV20 averted more IPD and CAP cases than PCV15 or PPV23 over the thirty years following vaccination: 353(360), 145(159) and 150(174) IPD and 581(673), 259(485) and 212(235) CAP cases at a vaccination age of 65(75) under base vaccine effectiveness assumptions. At the listed prices of PCV20 and PPV23 vaccines as of May 2023, both vaccines were cost-effective when vaccinating 65- or 75-year-olds with an ICER threshold of £20,000 per QALY. To achieve the same cost-effectiveness as PPV23, the additional cost of PCV20 should be less than £44(£91) at an ICER threshold of £20,000/QALY (£30,000/QALY) if vaccination age is 65 (or £54(£103) if vaccination age is increased to 75). We showed that both PPV23 and PCV20 were likely to be cost-effective. PCV20 was likely to avert more cases of pneumococcal disease in elderly adults in England than the current PPV23 vaccine, given input assumptions of a higher vaccine effectiveness and slower waning for PCV20.

Qualification of a 21-valent pneumococcal urine antigen detection assay and development of clinical positivity cutoffs

Aim: Serotype-specific assays detecting pneumococcal polysaccharides in bodily fluids are needed to understand the pneumococcal serotype distribution in non-bacteremic pneumonia. Methods: We developed a urine antigen detection assay and using urine samples from adult outpatients without pneumonia developed positivity cutoffs for both a previously published 15-valent and the new 21-valent assay. Clinical sensitivity was confirmed with samples from patients with invasive pneumococcal disease. Results: Total assay precision ranged from 7.6 to 17.8% coefficient of variation while accuracy ranged between 80 and 150% recovery, except for three serotypes where recoveries ranged from 32 to 60%. Clinical sensitivity was 86.4% and specificity was 96.5% across all 30 serotypes. Conclusion: The assay could potentially assess serotype-distribution in non-infected and infected participants with pneumococcal disease.

Follow-Up Study of Effectiveness of 23-Valent Pneumococcal Polysaccharide Vaccine Against All-Type and Serotype-Specific Invasive Pneumococcal Disease, Denmark

As a follow-up to a previous study, we investigated vaccine effectiveness (VE) of 23-valent pneumococcal polysaccharide vaccine (PPSV23) against invasive pneumococcal disease (IPD) among 1,254,498 persons >65 years of age as part of a vaccination program in Denmark during April 2020-January 2023. We assessed VE by using a Cox regression model and adjusted for age, sex, and underlying conditions. Using nationwide data, we estimated a VE of PPSV23 against all-type IPD of 32% and against PPSV23-serotype IPD of 41%. Because this follow-up study had more statistical power than the original study, we also estimated VE against IPD caused by PPSV23-serotypes excluding serotype 3; serotype 3; serotype 8; serotype 22F; PPSV23 non-PCV15 serotypes; PPSV23 non-PCV20 serotypes; and IPD over time. Our findings suggest PPSV23 vaccination can protect persons >65 years of age against IPD caused by all serotypes or serotype groupings, except serotype 3.

Cost-Effectiveness of 20-Valent Pneumococcal Conjugate Vaccine in Argentinean Adults

INTRODUCTION

In Argentina, vaccination with 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23; PCV13 → PPSV23) has been recommended for all adults aged ≥ 65 years and younger adults with chronic medical ("moderate-risk") or immunocompromising ("high-risk") conditions since 2017. With the approval of a 20-valent PCV (PCV20), we evaluated the cost-effectiveness of PCV20 versus current recommendations for moderate-/high-risk adults aged 18-64 years and all adults 65-99 years.

METHODS

A probabilistic cohort model was used to project lifetime outcomes and costs associated with invasive pneumococcal disease (IPD) and all-cause non-bacteremic pneumonia (NBP), and the expected impact of vaccination. Clinical outcomes were projected annually based on Argentinean data. Economic costs were estimated based on cases and corresponding medical costs (adjusted to 2023 USD) and costs of vaccine and administration. Cost-effectiveness of PCV20 was evaluated versus the current strategy, PCV13 → PPSV23, and alternatively, versus sequentially administered 15-valent PCV and PPSV23 (PCV15 →  PPSV23), and presented as cost per quality-adjusted life year gained; a healthcare system perspective was used. Costs and benefits were discounted at 3%/year.

RESULTS

PCV20 in lieu of PCV13 → PPSV23 among moderate-/high-risk adults aged 18-64 years and all adults 65-99 years (N = 13.4M) prevented 3838 IPD, 4377 inpatient NBP, and 6003 outpatient NBP cases, and 1865 disease-related deaths; relative to PCV15 → PPSV23 the corresponding reductions were 2775, 3285, 4518, and 1348. PCV20 was projected to be the dominant strategy versus PCV13 → PPSV23 and PCV15 → PPSV23 as overall costs were lower by $87.6M and $80.8M, respectively. In probabilistic sensitivity analyses, PCV20 was dominant (i.e., more effective, less costly) in 100% of 1000 simulations.

CONCLUSIONS

Analyses suggest implementing a PCV20 vaccination program in moderate-/high-risk adults aged 18-64 years and all adults ≥ 65 years-in lieu of PCV13 → PPSV23-would yield substantial reductions in pneumococcal disease and would be cost saving to the Argentinean healthcare system.

Insights into vaccines for elderly individuals: from the impacts of immunosenescence to delivery strategies

Immunosenescence increases the risk and severity of diseases in elderly individuals and leads to impaired vaccine-induced immunity. With aging of the global population and the emerging risk of epidemics, developing adjuvants and vaccines for elderly individuals to improve their immune protection is pivotal for healthy aging worldwide. Deepening our understanding of the role of immunosenescence in vaccine efficacy could accelerate research focused on optimizing vaccine delivery for elderly individuals. In this review, we analyzed the characteristics of immunosenescence at the cellular and molecular levels. Strategies to improve vaccination potency in elderly individuals are summarized, including increasing the antigen dose, preparing multivalent antigen vaccines, adding appropriate adjuvants, inhibiting chronic inflammation, and inhibiting immunosenescence. We hope that this review can provide a review of new findings with regards to the impacts of immunosenescence on vaccine-mediated protection and inspire the development of individualized vaccines for elderly individuals.

Cost-Effectiveness of 20-Valent Pneumococcal Conjugate Vaccine Among US Children with Underlying Medical Conditions

INTRODUCTION

A 20-valent pneumococcal conjugate vaccine (PCV20) was recently recommended for use among US children. We evaluated the cost-effectiveness of PCV20 among children aged 6 years with chronic medical conditions (CMC+) and children aged 6 years with immunocompromising conditions (IC) versus one and two doses of 23-valent pneumococcal polysaccharide vaccine (PPSV23), respectively.

METHODS

A probabilistic model was employed to depict 10-year risk of clinical outcomes and economic costs of pneumococcal disease, reduction in life years from premature death, and expected impact of vaccination among one cohort of children with CMC+ and IC aged 6 years. Vaccine uptake was assumed to be 20% for both PCV20 and PPSV23. Cost per quality-adjusted life year (QALY) gained was evaluated from the US societal and healthcare system perspectives; deterministic and probabilistic sensitivity analyses (DSA/PSA) were also conducted.

RESULTS

Among the 226,817 children with CMC+ aged 6 years in the US, use of PCV20 (in lieu of PPSV23) was projected to reduce the number cases of pneumococcal disease by 5203 cases, medical costs by US$8.7 million, and nonmedical costs by US$6.2 million. PCV20 was the dominant strategy versus PPSV23 from both the healthcare and societal perspectives. In the PSA, 99.9% of the 1000 simulations yielded a finding of dominance for PCV20. Findings in analyses of children with IC aged 6 years in the USA were comparable (i.e., PCV20 was the dominant vaccination strategy). Scenario analyses showed that increasing PCV20 uptake to 100% could potentially prevent > 22,000 additional cases of pneumococcal disease and further reduce medical and nonmedical costs by US$70.0 million among children with CMC+ and IC.

CONCLUSIONS

Use of PCV20 among young children with CMC+ and IC in the USA would reduce the clinical burden of pneumococcal disease and yield overall cost savings from both the US healthcare system and societal perspectives. Higher PCV20 uptake could further reduce the number of pneumococcal disease cases in this population.

Effectiveness of 13-valent pneumococcal conjugate vaccine against vaccine-serotype community acquired pneumococcal diseases among children in China: A test-negative case-control study

BACKGROUND

In 2016, China licensed 13-valent pneumococcal conjugate vaccine (PCV13) based on a study that demonstrated its immunogenicity is non-inferior to PCV7. However, the real-world effectiveness of PCV13 against vaccine-serotype pneumococcal diseases in China has limited evidence.

METHODS

A test-negative case-control study was conducted among children under 5 years old admitted to the Children's Hospital of Soochow University (SCH) with respiratory tract infections from January 2018 to December 2020. Cases were defined as children from whom the isolates were tested positive for Streptococcus pneumoniae (S. pneumoniae) with serotypes included in PCV13. Two control groups were included, one represented children with isolates positive for S. pneumoniae of non-PCV13 serotypes and the other comprised children who tested negative for S. pneumoniae. The S. pneumoniae-negative controls were selected by matching them to the cases based on gender, age and admission date in a 1:1 ratio. Vaccine effectiveness (VE) was calculated using a logistic regression model as (1- adjusted odds ratio) * 100 %.

RESULTS

A total of 2371 pneumococcal isolates were included in the analysis, of which 75.0 % (1779/2371) were covered by PCV13 serotypes. Consequently, these 1779 children were classified as cases, and 592 children were designated as non-PCV13 serotype controls. Another 1779 children were correspondingly recruited as S. pneumoniae-negative controls. Overall, 40 cases (2.3 %) and 148 controls (6.2 %) had received vaccination. The overall VE in the PCV13/non-PCV13 serotypes case-control study was 50.0 % (95 % CI: 15.0, 70.7), which was lower than the VE of 74.4 % (95 % CI: 60.7, 83.3) in the matched PCV13/S. pneumoniae-negative case-control study. VE was higher for ≥ 2 or ≥ 3 doses of vaccination compared to ≥ 1 dose. VE against specific PCV13 serotypes (6B, 6A and 19F) was higher than for other serotypes.

CONCLUSIONS

PCV13 vaccination demonstrates effectiveness against vaccine-serotype pneumococcal diseases in children, particularly for serotypes 6B, 6A and 19F.

Cost-effectiveness of the 20-valent pneumococcal conjugate vaccine versus the 23-valent pneumococcal polysaccharide vaccine for older adults in South Korea

BACKGROUND

Despite the demonstrated immunogenicity and safety of the 20-valent pneumococcal conjugate vaccine (PCV20) in older adults, the cost-effectiveness of the PCV20 was not examined compared to the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in South Korea. Therefore, this study aimed to evaluate the cost-effectiveness of PCV20 compared with PPSV23 in adults aged 65 years and older in South Korea.

METHODS

We constructed a Markov model that included susceptible states, invasive pneumococcal disease (IPD), non-bacteremic pneumonia (NBP), and death. The population was categorized by disease risk status (low risk, moderate risk, and high risk) and age group (65-74/75-84/85-99 years) at model entry. The annual incidence and mortality of IPD and NBP associated with PCV20 and PPSV23 were estimated based on serotype coverage, vaccine coverage, and vaccine effectiveness. The disease costs and utilities were obtained from previous studies. The incremental cost-effectiveness ratio (ICER) was used to evaluate cost-effectiveness within the threshold of 16,824 USD per quality-adjusted life-year (QALY).

RESULTS

Among the total population (n = 8,843,072), PCV20 prevented 1941 and 50,575 cases of IPDs and NBPs, respectively, and 898 and 8593 deaths due to IPDs and NBPs compared to PPSV23. The total medical cost per person was 12.11 USD higher in PCV20, with a gain of 0.0053 LYs and 0.0045 QALYs per person. The ICER for PCV20 and PPSV23 was 2270 USD/LY and 2677 USD/QALY.

CONCLUSIONS

In South Korea, PCV20 is a cost-effective option compared with PPSV23 for adults aged 65 years and older. These cost-effectiveness results provide evidence for decision-making regarding the approval and National Immunization Program implementation of PCV20.

Pneumococcal serotypes and risk factors in adult community-acquired pneumonia 2018-20; a multicentre UK cohort study

Background

Higher-valency pneumococcal vaccines are anticipated. We aimed to describe serotype distribution and risk factors for vaccine-serotype community-acquired pneumonia (CAP) in the two years pre-SARS-CoV-2 pandemic.

Methods

We conducted a prospective cohort study of adults hospitalised with CAP at three UK sites between 2018 and 2020. Pneumococcal serotypes were identified using a 24-valent urinary-antigen assay and blood cultures. Risk factors associated with vaccine-type pneumonia caused by serotypes in the 13-, 15- and 20-valent pneumococcal conjugate vaccines (PCV13, PCV15, PCV20) and 23-valent pneumococcal polysaccharide vaccine (PPV23) were determined from multivariable analysis.

Findings

Of 1921 adults hospitalised with CAP, 781 (40.7%, 95% confidence intervals (CI) 38.5-42.9%) had pneumococcal pneumonia. A single PCV13-serotype was detected in 242 (31.0%, 95% CI 27.8-34.3%) pneumococcal CAP patients, mostly serotype 3 (171/242, 70.7%, 95% CI 64.5-76.0%). The additional two PCV15-serotypes were detected in 31 patients (4%, 95% CI 2.8-5.6%), and PCV20-non13-serotypes in 192 (24.6%), with serotype 8 most prevalent (123/192, 64.1%, 95% CI 57.1-70.5%). Compared to PCV13-serotype CAP, people with PCV20-non13 CAP were younger (median age 62 versus 72 years, p < 0.001) and less likely to be male (44% versus 61%, p = 0.01). PPV23-non13-serotypes were found in 252 (32.3%, 95% CI 29.1-35.6%) pneumococcal CAP patients.

Interpretation

Despite mature infant pneumococcal programmes, the burden of PCV13-serotype pneumonia remains high in older adults, mainly due to serotype 3. PCV20-non13-serotype pneumonia is more likely in younger people with fewer pneumococcal risk factors.

Funding

Unrestricted investigator-initiated research grant from Pfizer, United Kingdom; support from National Institute for Health Research (NIHR) Biomedical Research Centre, Nottingham.

Cost-effectiveness analysis of adult pneumococcal conjugate vaccines for pneumococcal disease in Japan

BACKGROUND

The 23-valent pneumococcal polysaccharide vaccine (PPSV23) is used in the Japanese National Immunization Program for older adults and adults with increased risk for pneumococcal disease, however, disease incidence and associated burden remain high. We evaluated the cost-effectiveness of pneumococcal conjugate vaccines (PCVs) for adults aged 65 years and high-risk adults aged 60-64 years in Japan.

RESEARCH DESIGN AND METHODS

Using a Markov model, we evaluated lifetime costs using societal and healthcare payer perspectives and estimated quality-adjusted life-years (QALYs), and number of prevented cases and deaths caused by invasive pneumococcal disease (IPD) and non-IPD. The base case analysis used a societal perspective.

RESULTS

In comparison with PPSV23, the 20-valent PCV (PCV20) prevented 127 IPD cases 10,813 non-IPD cases (inpatients: 2,461, outpatients: 8,352) and 226 deaths, and gained more QALYs (+0.0015 per person) with less cost (-JPY22,513 per person). All sensitivity and scenario analyses including a payer perspective analysis indicated that the incremental cost-effectiveness ratios (ICERs) were below the cost-effectiveness threshold value in Japan (JPY5 million/QALY).

CONCLUSIONS

PCV20 is both cost saving and more effective than PPSV23 for adults aged 65 years and high-risk adults aged 60-64 years in Japan.

Serotype distribution, antimicrobial susceptibility and molecular epidemiology of invasive Streptococcus pneumoniae in the nine-year period in Serbia

Streptococcus pneumoniae is one of the leading bacterial pathogens that can cause severe invasive diseases. The aim of the study was to characterize invasive isolates of S. pneumoniae obtained during the nine-year period in Serbia before the introduction of the pneumococcal conjugate vaccines (PCVs) into routine vaccination programs by determining: serotype distribution, the prevalence and genetic basis of antimicrobial resistance, and genetic relatedness of the circulating pneumococcal clones. A total of 490 invasive S. pneumoniae isolates were included in this study. The serotype, antimicrobial susceptibility, and ST of the strains were determined by the Quellung reaction, disk- and gradient-diffusion methods, and multilocus sequence typing (MLST), respectively. The most common serotypes in this study were 3, 19F, 14, 6B, 6A, 19A, and 23F. The serotype coverages of PCV10 and PCV13 in children less than 2 years were 71.3 and 86.1%, respectively, while PPV23 coverage in adults was in the range of 85-96%, depending on the age group. Penicillin and ceftriaxone-non-susceptible isolates account for 47.6 and 16.5% of all isolates, respectively. Macrolide non-susceptibility was detected in 40.4% of isolates, while the rate of multidrug- and extensive-drug resistance was 20.0 and 16.9%, respectively. The MLST analysis of 158 pneumococci identified 60 different STs belonging to the 16 Clonal Complexes (CCs) (consisting of 42 STs) and 18 singletons. The most common CC/ST were ST1377, CC320, CC15, CC273, CC156, CC473, CC81, and CC180. Results obtained in this study indicate that the pre-vaccine pneumococcal population in Serbia is characterized by high penicillin and macrolides non-susceptibility, worrisome rates of MDR and XDR, as well as a high degree of genetic diversity. These findings provide a basis for further investigation of the changes in serotypes and genotypes that can be expected after the routine introduction of PCVs.

Cost-effectiveness of 20-valent pneumococcal conjugate vaccine compared with 23-valent pneumococcal polysaccharide vaccine among adults in a Norwegian setting

BACKGROUND

The morbidity and mortality of adult diseases caused by S. pneumoniae increase with age and presence of underlying chronic diseases. Currently, two vaccine technologies against S. pneumoniae are used: the 23-valent pneumococcal polysaccharide vaccine (PPV23) and the pneumococcal conjugate vaccines, one of which is the 20-valent pneumococcal conjugate vaccine (PCV20) that has recently been approved for adults.

OBJECTIVE

This study was conducted to investigate the cost-effectiveness of implementing PCV20 in a reimbursement scheme for Norwegian adults aged 18-99 years at risk of pneumococcal diseases and those aged 65 years and older at low risk compared to PPV23.

METHODS

An established Markov model was adapted to a Norwegian setting to estimate the economic and clinical consequences of vaccinating the Norwegian population in specific age and risk groups against pneumococcal diseases. Inputs for the model were found in Norwegian or Danish real-world evidence or retrieved from available studies. The costs and clinical outcomes were assessed using a health sector perspective and a lifetime time horizon.

RESULTS

The results showed that PCV20 was associated with better health outcomes including fewer disease cases, fewer disease-attributable fatalities, a higher gain of life years and quality-adjusted life years compared to PPV23. In addition, PCV20 had a lower total cost compared to PPV23. Therefore, PCV20 was the dominant vaccination strategy. The base case result was investigated in multiple sensitivity analyses, which showed that the results were robust to changes in input parameters and methodological assumptions, as PCV20 remained the dominant vaccination strategy in almost all scenarios.

CONCLUSION

Results showed that vaccinating the Norwegian adults with PCV20 was cost-effective compared to PPV23. Changes in the hospital cost of pneumonia, the price of PCV 20, the effectiveness of PCV20 against pneumonia, and the pneumonia disease incidence had the highest impact on the ICER, i.e., were the main drivers of the results.

A cost-effectiveness analysis of the 13-valent pneumococcal conjugated vaccine and the 23-valent pneumococcal polysaccharide vaccine among Thai older adult

Introduction

This study aims to assess the economic impact of introducing the 13-valent pneumococcal conjugate vaccine (PCV13) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) to Thai older adult aged ≥ 65  years who are healthy or with chronic health conditions and immunocompromised conditions from a societal perspective in order to introduce the vaccine to Thailand's National Immunization Program for the older adult.

Methods

A Markov model was adopted to simulate the natural history and economic outcomes of invasive pneumococcal diseases using updated published sources and Thai databases. We reported analyses as incremental cost-effectiveness ratios (ICER) in USD per quality-adjusted life year (QALY) gained. In addition, sensitivity analyses and budget impact analyses were conducted.

Results

The base-case analysis of all interventions (no vaccinations [current standard of care in Thailand], PPSV23, and PCV13) showed that PPSV23 was extendedly dominated by PCV13. Among healthy individuals or those with chronic health conditions, ICER for PCV13 was 233.63 USD/QALY; meanwhile, among individuals with immunocompromised conditions, ICER for PCV13 was 627.24 USD/QALY. PCV13 are economical vaccine for all older adult Thai individuals when compared to all interventions.

Conclusions

In the context of Thailand, PCV13 is recommended as the best buy and should be primarily prioritized when both costs and benefits are considered. Also, this model will be beneficial to the two-next generation pneumococcal vaccines implementation in Thailand.

Pneumococcal Serotype Evolution and Burden in European Adults in the Last Decade: A Systematic Review

Pneumococcal disease is a major cause of morbidity/mortality worldwide, and vaccination is an important measure in its prevention. Despite European children being vaccinated with pneumococcal conjugate vaccines (PCVs), pneumococcal infections are still a major cause of morbidity/mortality in adults with risk conditions and their vaccination might be an important prevention strategy. New PCVs have been approved, but information is lacking on their potential impact in European adults. In our review, we searched PubMed, MEDLINE, and Embase for studies on the additional PCV20 serotypes (concerning incidence, prevalence, disease severity, lethality, and antimicrobial resistance) in European adults, between January 2010 and April 2022, having included 118 articles and data from 33 countries. We found that these serotypes have become more prevalent in both invasive and non-invasive pneumococcal disease (IPD and NIPD), representing a significant proportion of cases (serotypes 8, 12F, 22F) and more serious disease and/or lethality (10A, 11A, 15B, 22F), showing antimicrobial resistance (11A, 15B, 33F), and/or affecting more vulnerable individuals such as the elderly, immunocompromised patients, and those with comorbidities (8, 10A, 11A, 15B, 22F). The relevance of pneumococcal adult carriers (11A, 15B, 22F, and 8) was also identified. Altogether, our data showed an increase in the additional PCV20 serotypes' prevalence, accounting for a proportion of approximately 60% of all pneumococcal isolates in IPD in European adults since 2018/2019. Data suggest that adults, as older and/or more vulnerable patients, would benefit from vaccination with higher-coverage PCVs, and that PCV20 may address an unmet medical need.

Systematic Review and Meta-Analysis of the Efficacy and Effectiveness of Pneumococcal Vaccines in Adults

New pneumococcal conjugate vaccines (PCVs), 15- and 20-valent (PCV15 and PCV20), have been licensed for use among U.S. adults based on safety and immunogenicity data compared with the previously recommended 13-valent PCV (PCV13) and 23-valent pneumococcal polysaccharide vaccines (PPSV23). We conducted a systematic review of the literature on PCV13 and PPSV23 efficacy (randomized controlled trials [RCTs]) or effectiveness (observational studies) against vaccine type (PCV13 type or PPSV23 type, respectively), invasive pneumococcal disease (IPD), and pneumococcal pneumonia (PP) in adults. We utilized the search strategy from a previous systematic review of the literature published during the period from January 2016 to April 2019, and updated the search through March 2022. The certainty of evidence was assessed using the Cochrane risk-of-bias 2.0 tool and the Newcastle-Ottawa scale. When feasible, meta-analyses were conducted. Of the 5085 titles identified, 19 studies were included. One RCT reported PCV13 efficacy of 75% (PCV13-type IPD) and 45% (PCV13-type PP). Three studies each reported PCV13 effectiveness against PCV13-type IPD (range 47% to 68%) and against PCV13-type PP (range 38% to 68%). The pooled PPSV23 effectiveness was 45% (95% CI: 37%, 51%) against PPSV23-type IPD (nine studies) and 18% (95% CI: -4%, 35%) against PPSV23-type PP (five studies). Despite the heterogeneity across studies, our findings suggest that PCV13 and PPSV23 protect against VT-IPD and VT-PP in adults.

Vaccine-Preventable Hospitalisations from Seasonal Respiratory Diseases: What Is Their True Value?

Hospitals in England experience extremely high levels of bed occupancy in the winter. In these circumstances, vaccine-preventable hospitalisations due to seasonal respiratory infections have a high cost because of the missed opportunity to treat other patients on the waiting list. This paper estimates the number of hospitalisations that current vaccines against influenza, pneumococcal disease (PD), COVID-19, and a hypothetical Respiratory Syncytial Virus (RSV) vaccine, could prevent in the winter among older adults in England. Their costs were quantified using a conventional reference costing method and a novel opportunity costing approach considering the net monetary benefit (NMB) obtained from alternative uses of the hospital beds freed-up by vaccines. The influenza, PD and RSV vaccines could collectively prevent 72,813 bed days and save over £45 million in hospitalisation costs. The COVID-19 vaccine could prevent over 2 million bed days and save £1.3 billion. However, the value of hospital beds freed up by vaccination is likely to be 1.1-2 times larger (£48-93 million for flu, PD and RSV; £1.4-2.8 billion for COVID-19) when quantified in opportunity cost terms. Considering opportunity costs is key to ensuring maximum value is obtained from preventative budgets, as reference costing may significantly underestimate the true value of vaccines.

Cost-effectiveness of use of 20-valent pneumococcal conjugate vaccine among adults in Germany

OBJECTIVES

Despite national recommendations for use of pneumococcal vaccines, rates of community-acquired pneumonia (CAP) and invasive pneumococcal disease (IPD) remain high in Germany. New pneumococcal conjugate vaccines (PCVs) with expanded coverage have the potential to reduce the pneumococcal disease burden among adults.

METHODS

Using a Markov model, we evaluated the lifetime outcomes/costs comparing 20-valent PCV (PCV20) with standard of care (SC) vaccinations for prevention of CAP and IPD among adults aged ≥60 years and at-risk adults aged 18-59 years in Germany. PCV20 also was compared with sequential vaccination with 15-valent PCV (PCV15) followed by PPSV23 in a scenario analysis.

RESULTS

Over the course of a lifetime (82 years), use of PCV20vs. SC would prevent 54,333 hospitalizations, 26368 outpatient CAP cases, 10946 disease-related deaths yield 74,694 additional life-years (LYs), while lowering total medical costs by 363.2 M €. PCV20 remained cost saving (i.e. dominant) versus SC even in numerous sensitivity analyses, including a sensitivity analysis assuming moderate effectiveness of the SC pneumococcal polysaccharide vaccine against noninvasive pneumococcal CAP. In several scenario analyses and a probabilistic sensitivity analysis, PCV20 was also cost-saving compared toPCV15 PPSV23 vaccination.

CONCLUSIONS

One dose of PCV20 among adults aged ≥60 years and adults aged 18-59 years with moderate- and high-risk conditions wouldsubstantially reduce pneumococcal disease, save lives, and be cost saving compared with SC.

A review of evidence for pneumococcal vaccination in adults at increased risk of pneumococcal disease: risk group definitions and optimization of vaccination coverage in the United Kingdom

INTRODUCTION

Pneumococcal disease (PD) significantly contributes to morbidity and mortality, carrying substantial economic and public health burden. This article is a targeted review of evidence for pneumococcal vaccination in the UK, the definitions of groups at particular risk of PD and vaccine effectiveness.

AREAS COVERED

Relevant evidence focusing on UK data from surveillance systems, randomized controlled trials, observational studies and publicly available government documents is collated and reviewed. Selected global data are included where appropriate.

EXPERT OPINION

National vaccination programs have reduced the incidence of vaccine-type PD, despite the rising prominence of non-vaccine serotypes in the UK. The introduction of higher-valency conjugate vaccines provides an opportunity to improve protection against PD for adults in risk groups. Several incentives are in place to encourage general practitioners to vaccinate risk groups, but uptake is low-suboptimal particularly among at-risk individuals. Wider awareness and understanding among the public and healthcare professionals may increase vaccination uptake and coverage. National strategies targeting organizational factors are urgently needed to achieve optimal access to vaccines. Finally, identifying new risk factors and approaches to risk assessment for PD are crucial to ensure those at risk of PD can benefit from pneumococcal vaccination.

Safety of the 15-valent pneumococcal conjugate vaccine: A phase I clinical trial

To evaluate the safety of the 15-valent pneumococcal conjugate vaccine (PCV15 (by LvZhu & Co. Ltd)) in healthy infants aged 2 months (minimum to 6 weeks) and 3 months old. This phase I clinical trial enrolled 80 subjects in Laishui County, Hebei Province, China. The total population was divided into 4 age groups on average: 20 adults (≥18 years) and 20 children (1-5 years) all received one vaccine dose; 20 infants (3 months) received the vaccine according to a 3-dose schedule at 0, 1, and 2 months. Twenty infants (2 months, minimum of 6 weeks old) received the vaccine according to a 3-dose schedule of 0, 2, and 4 months. The adverse events (AEs) until 30 days after each dose and serious adverse events (SAEs) until 6 months after the whole dose were reported. The solicited and unsolicited AE frequencies and laboratory indices were similar among the treatment groups. No vaccine-related SAEs were reported. Most vaccine-related adverse events consisting of systemic and local reactions were fever and pain. One hypersensitivity manifested as systemic urticaria that occurred on the third day after the second dose in the 2-month group. The 15-valent pneumococcal conjugate vaccine was generally well tolerated in infants.

Cost-effectiveness of revised US pneumococcal vaccination recommendations in underserved minority adults < 65-years-old

BACKGROUND

The 15- and 20-valent pneumococcal conjugate vaccines (PCV15/PCV20) were recently recommended for US adults, giving either PCV20 alone or PCV15 followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) to all 65 + -year-olds and to high-risk younger adults. However, general population recommendations to vaccinate all 50-year-olds could reduce racial pneumococcal disease disparities given greater risk in underserved minority populations.

METHODS

A Markov model examining hypothetical 50-year-old Black cohorts (serving as a proxy for underserved minorities) and non-Black cohorts estimated the incremental cost effectiveness of US adult pneumococcal vaccination recommendations compared to PCV20 or PCV15/PPSV23 for all 50-year-olds with no vaccination thereafter, or PCV20 or PCV15/PPSV23 for all at ages 50 and 65 years (50/65). Model parameters came from US databases, clinical trials, and Delphi panels. Cohorts were followed over their lifetimes from a healthcare perspective discounted at 3 %/year.

RESULTS

PCV15/PPSV23 given at ages 50/65 had greatest public health impact. In Black cohorts, PCV15/PPSV23 at age 50 cost $104,723/quality adjusted life year (QALY) gained compared to PCV20 at age 50, while PCV15/PPSV23 at 50/65 cost $240,952/QALY gained compared to PCV15/PPSV23 at age 50. Both current recommendation options were more expensive and less effective than other strategies in both cohorts. In sensitivity analyses, age-based PCV20 or PCV15/PPSV23 use at ages 50 or 50/65 could be favorable depending on vaccine effectiveness or differential vaccine uptake, while current recommendations remained unfavorable.

CONCLUSION

Recent risk-based US adult pneumococcal vaccination recommendations for adults < 65-years-old, were economically and clinically unfavorable compared to general population vaccination of all 50-year-olds in Black and non-Black cohorts. An age-based pneumococcal vaccination recommendation at age 50 years may reduce inequities in pneumococcal disease burden.

Effectiveness of the 23-valent pneumococcal polysaccharide vaccine against community-acquired pneumonia in older individuals after the introduction of childhood 13-valent pneumococcal conjugate vaccine: A multicenter hospital-based case-control study in Japan

BACKGROUND

In the era of childhood pneumococcal conjugate vaccine (PCV) immunization, especially 13-valent pneumococcal conjugate vaccine (PCV13) immunization, serotype replacement of Streptococcus pneumoniae and herd immunity in adults have been reported worldwide. Therefore, continuous evaluation of the effectiveness of the pneumococcal vaccine in adults is crucial because vaccine effectiveness may change owing to these factors. The purpose of this study was to evaluate the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) against all-cause pneumonia and pneumococcal pneumonia in older individuals with community-acquired pneumonia (CAP) after the introduction of childhood PCV13 in Japan, a topic that has remained largely unexplored.

METHODS

We evaluated pneumococcal vaccine effectiveness in this multicenter, matched case-control study conducted in hospitals and clinics. Cases included patients (aged ≥ 65 years) newly diagnosed with CAP between October 2016 and September 2019. A maximum of five non-pneumonia control patients matched for sex, school grade, date of outpatient visit, and medical institution were selected for each case. Conditional logistic regression models were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of pneumococcal vaccines for the occurrence of all-cause CAP and pneumococcal CAP.

RESULTS

The analysis included 740 individuals (142 patients and 598 controls). The median age of participants was 75 years (men: 54%). The adjusted OR for pneumococcal vaccination against all-cause CAP was 1.31 (95% CI: 0.84-2.06), while that for PPSV23 vaccination in the previous 5 years was 1.33 (95% CI: 0.85-2.09). The adjusted OR for PPSV23 vaccination in the previous 5 years against pneumococcal CAP was 0.93 (95% CI: 0.35-2.50).

CONCLUSIONS

This study was unable to demonstrate the effectiveness of PPSV23 against all-cause and pneumococcal pneumonia after the introduction of childhood PCV13 in Japan. Nonetheless, additional studies are needed to validate these results.

Effectiveness of the 23-valent pneumococcal polysaccharide vaccine against invasive pneumococcal disease among 948,263 individuals ≥ 65 years of age: a Danish cohort study

This study aimed to estimate the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPV23) against invasive pneumococcal disease (IPD) among individuals ≥ 65 years of age. We used Danish nationwide databases to obtain information on PPV23 vaccination, covariates, and IPD and linked data on an individual level using a unique personal identifier. A total of 948,263 individuals were included and followed between June 15, 2020, and September 18, 2021 (58.6% were vaccinated during follow-up). The adjusted vaccine effectiveness was 42% (95% confidence interval (CI): 9–63%) for all-serotype IPD and 58% (95% CI: 21–78%) for PPV23-serotype IPD, using no vaccination as the reference.

Real-world effectiveness of pneumococcal vaccination in older adults: Cohort study using the UK Clinical Practice Research Datalink

Background

The 23-valent pneumococcal polysaccharide vaccine (PPV23) is recommended for UK older adults, but how age moderates effectiveness is unclear.

Methods

Three annual cohorts of primary-care patients aged≥65y from the Clinical Practice Research Datalink selected from 2003–5 created a natural experiment (n = 324,804), reflecting the staged introduction of the vaccine. The outcome was symptoms consistent with community-acquired pneumococcal pneumonia (CAP) requiring antibiotics or hospitalisation. We used the prior event rate ratio (PERR) approach to address bias from unmeasured confounders.

Results

Vaccinated patients had higher rates of CAP in the year before vaccination than their controls, indicating the potential for confounding bias. After adjustment for confounding using the prior event rate ratio (PERR) method, PPV23 was estimated to be effective against CAP for two years after vaccination in all age sub-groups with hazard ratios (95% confidence intervals) of 0.86 (0.80 to 0.93), 0.74 (0.65 to 0.85) and 0.65 (0.57 to 0.74) in patients aged 65–74, 75–79 and 80+ respectively in the 2005 cohort. Age moderated the effect of vaccination with predicted risk reductions of 8% at 65y and 29% at 80y.

Conclusions

PPV23 is moderately effective at reducing CAP among UK patients aged≥65y, in the two years after vaccination. Vaccine effectiveness is maintained, and may increase, in the oldest age groups in step with increasing susceptibility to CAP.

Cost-effectiveness of using a 20-valent pneumococcal conjugate vaccine to directly protect adults in England at elevated risk of pneumococcal disease

OBJECTIVES

Despite the current pneumococcal vaccination program in England for older adults and adults with underlying conditions, disease burden remains high. We evaluated cost-effectiveness of 20-valent pneumococcal conjugate vaccine (PCV20) compared to current pneumococcal recommendations for adults in England.

METHODS

Lifetime outcomes/costs of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP) among adults aged 65-99 years and adults aged 18-64 years with underlying conditions in England were projected using a probabilistic cohort model. Vaccination with PCV20 was compared with 23-valent pneumococcal polysaccharide vaccine (PPV23) from the National Health Service perspective.

RESULTS

PCV20 was cost saving compared with PPV23 in base case and most sensitivity analyses. In the base case, replacing PPV23 with PCV20 prevented 7,789 and 140,046 cases of IPD and hospitalized CAP, respectively, and 22,199 associated deaths, resulting in incremental gain of 91,375 quality-adjusted life-years (QALYs) and incremental savings of £160M. In probabilistic sensitivity analyses, PCV20 (vs. PPV23) was cost saving in 85% of simulations; incremental cost per QALY was below £30,000 in 99% of simulations.

CONCLUSIONS

PCV20 vaccination in adults aged 65-99 years and those aged 18-64 years with underlying comorbidities in England is expected to prevent more hospitalizations, save more lives, and yield lower overall costs than current recommendations for PPV23.

The remarkable history of pneumococcal vaccination: an ongoing challenge

Although it varies with age and geographical distribution, the global burden of infection with Streptococcus pneumoniae (pneumococcus) remains considerable. The elderly, and younger adults with comorbid conditions, are at particularly high risk of pneumococcal infection, and this risk will increase as the population ages. Vaccination should be the backbone of our current strategies to deal with this infection.

Main body: This manuscript reviews the history of the development of pneumococcal vaccines, and the impact of different vaccines and vaccination strategies over the past 111 years. It documents the early years of vaccine development in the gold mines of South Africa, when vaccination with killed pneumococci was shown to be effective, even before the recognition that different pneumococci were antigenically distinct. The development of type-specific vaccines, still with whole killed pneumococci, showed a high degree of efficacy. The identification of the importance of the pneumococcal capsule heralded the era of vaccination with capsular polysaccharides, although with the advent of penicillin, interest in pneumococcal vaccine development waned. The efforts of Austrian and his colleagues, who documented that despite penicillin therapy, patients still died from pneumococcal infection in the first 96 h, ultimately led to the licensing first of a 14-valent pneumococcal polysaccharide in 1977 followed by the 23-valent pneumococcal polysaccharide in 1983. The principal problem with these, as with other polysaccharide vaccines, was that that they failed to immunize infants and toddlers, who were at highest risk for pneumococcal disease. This was overcome by chemical linking or conjugation of the polysaccharide molecules to an immunogenic carrier protein. Thus began the era of pneumococcal conjugate vaccine (PCV), starting with PCV7, progressing to PCV10 and PCV13, and, most recently, PCV15 and PCV20. However, these vaccines remain serotype specific, posing the challenge of new serotypes replacing vaccine types. Current research addresses serotype-independent vaccines which, so far, has been a challenging and elusive endeavor.

Conclusion: While there has been enormous progress in the development of pneumococcal vaccines during the past century, attempts to develop a vaccine that will retain its efficacy for most pneumococcal serotypes are ongoing.

Pneumococcal vaccination coverage and willingness in mainland China

OBJECTIVES

To estimate the coverage and willingness of pneumococcal vaccination and further explore the influencing factors of vaccination willingness among people in mainland China.

METHODS

Literature searches were conducted independently by two researchers in English- and Chinese-language databases from database inception to October 6, 2021. A random-effects meta-analysis model was used to derive summary vaccination coverage and willingness. Predefined subgroup analysis and meta-regression were performed to explore the sources of heterogeneity.

RESULTS

97 studies were included in this meta-analysis. The summary vaccination coverage in 76 included studies was 21.7% (95% CI: 17.2 - 26.5%). Subgroup analysis shows that the summary coverage was 29.0% (95% CI, 20.4 - 39.1%) among permanent residents and 20.7% (95% CI, 12.4 - 35.9%) among floating residents. The eastern and central regions presented higher coverage than the western region. Notable differences were observed between the various study populations. 27 studies provided an estimation of vaccination willingness, with a summary willingness of 51.2% (95% CI, 40.4 - 61.9%). In subgroup analysis the summary willingness was 57.9 % (95% CI, 48.3 - 67.2%) in urban areas and 52.3 % (95% CI, 40.8 - 63.8%) in rural areas. Parents with children and people with a history of pneumonia were more willing to be vaccinated than the elderly. Recommendations by family members and physicians, previous pneumococcal and influenza vaccination, perceived vaccination effectiveness and severity of disease and a history of pneumonia contributed to vaccination willingness.

CONCLUSIONS

Compared to global estimates and to other countries, pneumococcal vaccination coverage and willingness are at a lower level in mainland China. Recommendations for vaccination by family members and doctors, a history of vaccination and the perception of pneumonia and vaccination are associated with greater willingness to be vaccinated. This article is protected by copyright. All rights reserved.

Public health and budgetary impact of 20-valent pneumococcal conjugate vaccine for adults in England

BACKGROUND

. Despite use of 23-valent pneumococcal polysaccharide vaccine (PPV23) in England, disease burden among at-risk adults remains high. We evaluated the public health and budgetary impact of 20-valent pneumococcal conjugate vaccine (PCV20) compared to the current adult pneumococcal vaccination program.

METHODS

Five-year outcomes and costs of invasive pneumococcal disease (IPD) and community-acquired pneumonia (CAP) among adults aged 65-99 years and adults aged 18-64 years with underlying conditions in England were projected using a deterministic cohort model. Hypothetical vaccination with PCV20 versus PPV23 was compared from National Health Service (NHS) perspective.

RESULTS

Replacing PPV23 with PCV20 would prevent 785 IPD hospitalizations, 11,751 CAP hospitalizations, and 1,414 deaths over five years, and would reduce medical care costs by £48.5M. With vaccination costs higher by £107.2M, projected net budgetary impact is £58.7M. The budgetary impact would be greatest in year one (£26.3M), and would decrease over time (to £1.6M by year five). The average budget increase (£11.7M/year) represents <0.01% of the Department of Health and Social Care budget and <3% of the vaccines budget.

CONCLUSIONS

Use of PCV20 among adults currently eligible for PPV23 in England would substantially reduce the burden of pneumococcal disease, with modest budgetary impact.

Cost-Effectiveness of Newly Recommended Pneumococcal Vaccination Strategies in Older Underserved Minority Adults in the USA

INTRODUCTION

US pneumococcal vaccination recommendations for adults aged 65 years or older recently changed, with options for either 20-valent pneumococcal conjugate vaccine (PCV20) or the combination of 15-valent conjugate vaccine (PCV15) followed by 23-valent polysaccharide vaccine (PPSV23) 1 year later. Underserved minority adults are at higher risk for pneumococcal disease.

METHODS

A Markov decision analysis model estimated the incremental cost-effectiveness of the newly adopted general population pneumococcal vaccination strategies in older underserved minority adults. The model examined hypothetical 65-year-old US Black cohorts (serving as a proxy for underserved minorities) and non-Black cohorts receiving PCV20 or PCV15/PPSV23, or no vaccination. Main outcome measures included incremental cost-effectiveness per quality-adjusted life year (QALY) gained and pneumococcal disease public health outcomes.

RESULTS

Black cohorts had a greater risk of pneumococcal disease hospitalization compared to non-Black cohorts. In Black cohorts, total per person PCV20 strategy costs, compared to no vaccination, were $124 higher while gaining 0.00073 QALY, or $169,540/QALY gained. PCV15/PPSV23 cost $535,797/QALY compared to PCV20. In the non-Black cohort, PCV20 cost $210,529/QALY gained compared to no vaccination and PCV15/PPSV23 cost $728,423/QALY. Plausible variation of vaccine effectiveness minimally affected PCV20 strategy results and made PCV15/PPSV23 more unfavorable. In scenarios where the simpler one-vaccine PCV20 strategy increased absolute vaccine uptake by 10%, PCV20 cost-effectiveness changed minimally while PCV15/PPSV23 cost in excess of $6 million/QALY in the Black cohort. In probabilistic sensitivity analyses that varied all parameters simultaneously, PCV15/PPSV23 was unlikely to be favored at thresholds less than $500,000/QALY gained.

CONCLUSION

General population recommendations for PCV20 use are substantially more economically reasonable in Black and non-Black older adult populations than PCV15/PPSV23. If using a single vaccine increases uptake, which is potentially more likely in the underserved, then PCV20 use becomes even more favorable.

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.

23-Valent Pneumococcal Polysaccharide Vaccination Does Not Prevent Community-Acquired Pneumonia Hospitalizations Due to Vaccine-Type Streptococcus pneumoniae

Controversy exists regarding the clinical effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) for the prevention of serotype-specific community-acquired pneumonia (CAP). The objective of this study was to define the effectiveness of PPSV23 for the prevention of CAP hospitalizations due to vaccine-contained serotypes. This secondary analysis was a nested case–control, test-negative study design of adult patients hospitalized for CAP between 1 June 2014 and 31 March 2017. Cases included patients with CAP due to a S. pneumoniae serotype contained in the PPSV23. Urinary antigen detection of the 23 serotypes was performed. In the study, PPSV23 vaccination alone and no other pneumococcal vaccination was the primary exposure of interest. Vaccine effectiveness was calculated as (1-OR) × 100. Adjusted estimates were obtained from a logistic regression model that controlled for confounding variables. A total of 3686 patients were included in the analysis. The PPSV23 vaccination was documented in 608 (16%) patients, and the PPSV23-serotype CAP was detected in 48 (8%) PPSV23-vaccinated patients and in 288 (9%) non-vaccinated patients. Unadjusted vaccine effectiveness for preventing PPSV23-serotype CAP was 17% (95% CI: −13% to 40%). Adjusted estimates for preventing PPSV23-serotype CAP was 14% (95% CI: −17% to 38%). In this study, PPSV23 vaccination offered no protection against PPSV23-serotype CAP hospitalization in adults. This is the first PPSV23 vaccine effectiveness study from United States that utilized a urinary antigen detection assay as the main method for S. pneumoniae serotyping. This study highlights the need for more effective vaccines in the prevention of hospitalization due to S. pneumoniae CAP.

Use of 15-Valent Pneumococcal Conjugate Vaccine and 20-Valent Pneumococcal Conjugate Vaccine Among U.S. Adults: Updated Recommendations of the Advisory Committee on Immunization Practices - United States, 2022

In 2021, 20-valent pneumococcal conjugate vaccine (PCV) (PCV20) (Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc.) and 15-valent PCV (PCV15) (Merck Sharp & Dohme Corp.) were licensed by the Food and Drug Administration for adults aged ≥18 years, based on studies that compared antibody responses to PCV20 and PCV15 with those to 13-valent PCV (PCV13) (Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc.). Antibody responses to two additional serotypes included in PCV15 were compared to corresponding responses after PCV13 vaccination, and antibody responses to seven additional serotypes included in PCV20 were compared with those to the 23-valent pneumococcal polysaccharide vaccine (PPSV23) (Merck Sharp & Dohme Corp.). On October 20, 2021, the Advisory Committee on Immunization Practices (ACIP) recommended use of either PCV20 alone or PCV15 in series with PPSV23 for all adults aged ≥65 years, and for adults aged 19-64 years with certain underlying medical conditions or other risk factors* who have not previously received a PCV or whose previous vaccination history is unknown. ACIP employed the Evidence to Recommendation (EtR) framework,^† using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE)^§ approach to guide its deliberations regarding use of these vaccines. Before this, PCV13 and PPSV23 were recommended for use for U.S. adults and the recommendations varied by age and risk groups. This was simplified in the new recommendations.

Cost-effectiveness of 20-valent pneumococcal conjugate vaccine in Denmark compared with PPV23

BACKGROUND

A new 20-valent pneumococcal conjugate vaccine (PCV20) provides protection against 20 pneumococcal serotypes. The vaccine has the potential to decrease the impact of pneumococcal diseases in society and to increase health among vulnerable persons.

AIM

This study investigates the cost-effectiveness of vaccinating Danish adults in different age groups and risk of pneumococcal disease with PCV20 compared to the 23-valent pneumococcal polysaccharide vaccine (PPV23) - either as PCV20 compared to PPV23 or as PPV23 followed by PCV20 compared to PPV23.

METHODS

A Markov model adapted to the Danish setting was developed to estimate clinical outcomes and costs of vaccinating the Danish population in specific age and risk groups. The model used a restricted societal perspective and estimated outcomes and costs using a lifetime time horizon. To estimate the clinical outcomes and costs, inputs on vaccine effectiveness and waning were retrieved from other studies whereas data on risk groups, coverage and costs were based on real-world data.

RESULTS

The results showed that in all scenarios the incidence and mortality of pneumococcal disease were reduced when vaccinating with PCV20, resulting in lower costs. For the vaccine target group of adults aged ≥18 years at moderate or high risk and all adults aged ≥65 years both in the case of PPV23+PCV20 compared to PPV23 and in case of PCV20 compared to PPV23 vaccination with PCV20 was found to be a dominant strategy gaining 1,350 or 5,821 quality-adjusted life years (QALYs), respectively, and reducing total costs by 60 or 396 million EUR, respectively, as compared to PPV23 vaccination alone. Similar results of dominant PCV20 strategy were found for other age and risk group comparisons. Both deterministic and probabilistic sensitivity analyses confirmed the results being robust to changes in input parameters and applied assumptions.

LIMITATIONS

Like other modelling studies, this analysis has limitations such as lack of detailed data for some inputs.

CONCLUSION

Vaccination with PCV20 reduced the incidence and mortality of pneumococcal diseases in Danish adults compared to PPV23. This reduction has the potential to reduce the financial burden related to managing diseases while also increasing public health.

A novel pneumococcal protein-polysaccharide conjugate vaccine based on biotin-streptavidin

Pneumococcal disease is a serious public health problem worldwide and an important cause of morbidity and mortality among children and adults in developing countries. Although vaccination is among the most effective approaches to prevent and control pneumococcal diseases, approved vaccines have limited protective effects. We developed a pneumococcal protein-polysaccharide conjugate vaccine that is mediated by the non-covalent interaction between biotin and streptavidin. Biotinylated type IV capsular polysaccharide was incubated with a fusion protein containing core streptavidin and Streptococcus pneumoniae virulence protein and relying on the non-covalent interaction between biotin and streptavidin to prepare the protein-polysaccharide conjugate vaccine. Analysis of vaccine efficacy revealed that mice immunized with the protein-polysaccharide conjugate vaccine produced antibodies with high potency against virulence proteins and polysaccharide antigens and were able to induce Th1 and Th17 responses. The antibodies identified using an opsonophagocytic assay were capable of activating the complement system and promoting pathogen elimination by phagocytes. Additionally, mice immunized with the protein-polysaccharide conjugate vaccine and then infected with a lethal dose of Streptococcus pneumoniae demonstrated induced protective immunity. The data indicated that the pneumococcal protein-polysaccharide (biotin-streptavidin) conjugate vaccine demonstrated broad-spectrum activity applicable to a wide range of people and ease of direct coupling between protein and polysaccharide. These findings provide further evidence for the application of biotin-streptavidin in S. pneumoniae vaccines.

Invasive pneumococcal disease, pneumococcal pneumonia and all-cause pneumonia in Hong Kong during the COVID-19 pandemic compared with the preceding 5 years: a retrospective observational study

OBJECTIVES

To compare the incidence and severity of invasive pneumococcal diseases (IPDs), pneumococcal pneumonia and all-cause pneumonia during the COVID-19 pandemic period with universal masking and social distancing with that of previous 5 years.

DESIGN

Retrospective observational study on incidence of IPDs, pneumococcal pneumonia and all-cause pneumonia between January 2015-December 2019 and March 2020-March 2021. January-February 2020 was excluded from analysis as it was treated as a transitional period between normal time and pandemic.

SETTING

Episode-based data by retrieval of hospitalisation records from the Hospital Authority's territory-wide electronic medical record database in Hong Kong.

PARTICIPANTS

Hospitalised patients with IPD (n=742), pneumococcal pneumonia (n=2163) and all-cause pneumonia (including COVID-19 pneumonia, n=453 999) aged 18 years or above. Control diagnoses were included to assess confounding from health-seeking behaviours.

PRIMARY AND SECONDARY OUTCOMES

Primary outcome is the incidence of diseases between two periods. Secondary outcomes include disease severity surrogated by length of stay and mortality.

RESULTS

Monthly average number of IPD, pneumococcal pneumonia and all-cause pneumonia hospitalisation significantly decreased by 88.9% (95% CI 79.8% to 98.0%, p<0.0005), 72.5% (95% CI 65.9% to 79.1%, p<0.0005) and 17.5% (95% CI 16.8% to 18.2%, p<0.0005), respectively. Changes in trend from January 2015-December 2019 to March 2020-March 2021 were -70% (95% CI -87% to -35%, p=0.0025), -43% (95% CI -59% to -19%, p=0.0014) and -11% (95% CI -13% to -10%, p<0.0005), respectively. Length of stay for IPD and pneumococcal pneumonia episodes were insignificantly different in the two periods. No reductions in hospitalisations for control diagnoses were observed.

CONCLUSIONS

Incidence of IPD, pneumococcal pneumonia and all-cause pneumonia decreased during the COVID-19 pandemic. This was observed with universal masking and social distancing. We postulated this is related to reduced transmission of respiratory viruses and bacteria.

A review of current data to support decision making for introduction of next generation higher valency pneumococcal conjugate vaccination of immunocompetent older adults in the UK

INTRODUCTION

The burden of pneumococcal disease in older UK adults remains substantial. Higher valency pneumococcal conjugate vaccines (PCVs) are currently in development with adult formulations for two of these anticipated to become available in 2022. This article collates and reviews relevant candidate data now available that may be used to support cost effectiveness assessments of vaccinating immunocompetent UK adults aged ≥65-years with PCVs.

AREAS COVERED

This article uses published data from surveillance systems, randomized controlled trials and observational studies. It focuses on local data from the UK but where these are either limited or not available relevant global data are considered.

EXPERT OPINION

The body of relevant data now available suggests the UK is well placed to assess the cost effectiveness of vaccinating immunocompetent ≥65-year olds with new generation higher valency PCVs. Recent contemporary data provide important new and robust insights into the epidemiology of pneumococcal disease in older UK adults and help to address much of the uncertainty and data gaps associated with previous analyses. Using these data to make informed decisions about use of new higher valency PCVs for routine use in older adults will be important for public health in the UK.

Effectiveness of Pneumococcal Vaccination Against Hospitalized Pneumococcal Pneumonia in Older Adults: A Prospective, Test-Negative Study

BACKGROUND

Despite use of the 13-valent pneumococcal conjugate vaccine (PCV13) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) over the last decade, the disease burden of pneumococcal pneumonia is still high. We evaluated the field effectiveness of PCV13, PPSV23, and sequential vaccination against pneumococcal pneumonia in older adults.

METHODS

This prospective multicenter study was conducted in adults aged ≥ 65 years with hospitalized community-acquired pneumonia (CAP) between September 2015 and August 2017. The case-control test-negative design was used to estimate vaccine effectiveness (VE) against pneumococcal CAP.

RESULTS

Of 1,525 cases with hospitalized CAP, 167 (11.0%) were identified as pneumococcal CAP. In the elderly aged ≥65 years, the adjusted VE of pneumococcal vaccines against pneumococcal CAP was statistically insignificant: 40.0% (95% CI -10.8% to 67.5%) for PCV13 and 11.0% (95% CI, -26.4% to 37.3%) for PPSV23. However, in the younger subgroup (aged 65-74 years), sequential PCV13/PPSV23 vaccination showed the highest adjusted VE of 80.3% (95% CI 15.9% to 95.4%), followed by single-dose PCV13 (adjusted VE 66.4%; 95% CI 0.8% to 88.6%) and PPSV23 (adjusted VE 18.5%; 95% CI -38.6% to 52.0%).

CONCLUSIONS

Sequential PCV13/PPSV23 vaccination is most effective for preventing pneumococcal CAP among the elderly aged 65-74 years.

Health economic evaluation of introducing a PPSV23-based vaccination programme to adults aged 65 and above, and an extension to the 60-64 age group in Denmark

BACKGROUND

To estimate the health economic consequences of the recently introduced PPSV23 vaccination programme for persons aged 65+ in Denmark and of a potential extension of the programme to include persons aged 60-64 years.

RESEARCH DESIGN AND METHODS

A Markov model was adapted to the Danish healthcare setting to simulate the epidemiological and economic burden of invasive pneumococcal disease and non-bacteremic pneumococcal pneumonia using information from published sources and Danish databases.

RESULTS

We found that the recent introduction of an age-based vaccination programme offering PPSV23 vaccination to the population of persons aged 65+ in Denmark will lead to a societal gain of EUR 72.0 million and prevent 19,707 cases of pneumococcal disease and 1,308 deaths per 1 million persons during the five-year study period.Similarly, we estimate that extending the programme to include persons aged 60-64 will lead to a gain of EUR 14.6 million per 1 million persons and prevent an additional 6,223 cases of pneumococcal disease and 185 deaths.

CONCLUSION

The recent introduction of the age-based vaccination programme offering PPSV23 vaccination to all persons aged 65+ in Denmark is cost-effective. This is also the case if the programme is extended to include persons aged 60-64.

Vaccination with LytA, LytC, or Pce of Streptococcus pneumoniae Protects against Sepsis by Inducing IgGs That Activate the Complement System

The emergence of non-vaccine serotypes of Streptococcus pneumoniae after the use of vaccines based in capsular polysaccharides demonstrates the need of a broader protection vaccine based in protein antigens and widely conserved. In this study, we characterized three important virulence factors of S. pneumoniae namely LytA, LytC, and Pce as vaccine candidates. These proteins are choline-binding proteins that belong to the cell wall hydrolases’ family. Immunization of mice with LytA, LytC, or Pce induced high titers of immunoglobulins G (IgGs) of different subclasses, with IgG1, IgG2a, and IgG2b as the predominant immunoglobulins raised. These antibodies activated the classical pathway of the complement system by increasing the recognition of C1q on the surface of pneumococcal strains of different serotypes. Consequently, the key complement component C3 recognized more efficiently these strains in the presence of specific antibodies elicited by these proteins, activating, therefore, the phagocytosis. Finally, a mouse sepsis model of infection was established, confirming that vaccination with these proteins controlled bacterial replication in the bloodstream, increasing the survival rate. Overall, these results demonstrate that LytA, LytC, and Pce can be protein antigens to be contained in a future universal vaccine against S. pneumoniae.

Efficacy and effectiveness of a 23-valent polysaccharide vaccine against invasive and noninvasive pneumococcal disease and related outcomes: a review of available evidence

Introduction: Routine pneumococcal vaccination for adults aged ≥60 or ≥65 years and those with underlying at-risk and high-risk conditions is recommended in many countries. However, studies estimating the effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPSV23) have revealed mixed results, partly due to variability in study design and endpoints used to assess outcomes.Areas covered: The authors conducted a literature review of independently randomized trials and real-world studies published from 2010 to 2020 that assessed the effectiveness and efficacy of PPSV23 against vaccine-type or any-serotype invasive and noninvasive pneumococcal disease in adults aged ≥60 years. The authors also evaluated differences in study design that may contribute to the heterogeneity of available evidence.Expert opinion: Policy decisions regarding the inclusion of vaccines into national immunization plans should consider study quality and limitations. This review shows that PPSV23 is effective against vaccine-type invasive pneumococcal disease and vaccine-type pneumococcal pneumonia and can lower the burden of vaccine-type pneumococcal pneumonia. PPSV23-conferred protection may be lower in adults aged ≥75 years, those with certain underlying conditions, and individuals who were vaccinated >5 years before disease onset. This is an important finding that supports the benefit of PPSV23 vaccination for older adults.