Re-emergence of invasive pneumococcal disease (IPD) and increase of serotype 23B after easing of COVID-19 measures, Switzerland, 2021

Hospital burden of pneumococcal disease in Spain (2016-2022): A retrospective study

Pneumococcal disease is a leading cause of morbidity and mortality worldwide. From 2016 to 2022, 358,603 hospitalized patients were identified as having pneumococcal disease. The overall annual hospitalization rate was 108.9 hospitalizations per 100,000 people, which significantly increased with age, reaching 748.0 hospitalizations per 100,000 among those aged ≥90 years. The hospitalization rates for pneumococcal pneumonia, meningitis, and sepsis were 25.4, 0.7, and 3.5 hospitalizations per 100,000 people, respectively, reaching the highest rates in those ≥90 years of age for pneumococcal pneumonia and sepsis, with 241.6 and 22.0 hospitalizations per 100,000 people, respectively, and in those <1 year of age for meningitis, with 3.4 hospitalizations per 100,000 people. The total number of deaths among all hospitalized pneumococcal infection patients was 51,668, with a total case fatality rate of 14.4%. The case fatality rates for pneumococcal pneumonia, meningitis, and sepsis were 7.9%, 10.6%, and 19.8%, respectively. The case fatality rate increased dramatically with age. Most patients presented with at least one underlying condition. The case fatality rate among patients with at least one comorbidity was significantly higher (p < .05) than that among patients without underlying conditions (16.0% vs. 3.2%, respectively), with a fivefold greater probability of death (OR = 5.7). During this period, the annual cost of hospitalizations for the health system exceeded EUR 383 million. Thus, the use of new broad-spectrum PCVs and improved vaccination protocols for elderly individuals and people with comorbidities could help reduce the high hospital burden of disease and mortality due to pneumococcal infection in our country.

Serotype epidemiology and case-fatality risk of invasive pneumococcal disease: a nationwide population study from Switzerland, 2012-2022

In Switzerland, thirteen-valent pneumococcal conjugate vaccine (PCV13) has been introduced in 2011. During the COVID-19 pandemic, cases of invasive pneumococcal disease (IPD) have decreased but consequences on the serotype epidemiology are less clear. The objective of the study has been to analyse the impact of PCV13 introduction and the COVID-19 pandemic on the IPD epidemiology and investigate the changes in the case fatality risk (CFR). We analysed data from the Swiss nationwide surveillance for the period 2012-2022. Poisson and logistic regression analyses were performed allowing us to inspect trends over time and to define serotypes that are associated with case fatality. In total, 8747 IPD cases were included from 2012 to 2022. IPD incidence dropped in the years 2020 (6.0/100,000) and 2021 (5.5/100,000) but recovered in 2022 (9.1/100,000). While the incidence numbers of patients >65 years did not reach the pre-pandemic level, numbers significantly increased in infants <1 year in 2022 (IRR 1.08, 95%CI: 1.01-1.16). The incidence of PCV13 serotypes among all IPD cases decreased until 2019 before increasing again during the pandemic (in 2022). Logistic regression analyses revealed that the PCV20 serotype 11A (OR: 1.76, 95%CI: 1.14-2.64), and the PCV13 serotypes 3 (OR: 1.26, 95% CI: 1.04-1.53) and 19F (OR: 1.76, 95%CI: 1.14-2.65) were significantly associated with increased CFR. In conclusion, the COVID-19 pandemic has had only minor temporary effects on the serotype distribution. Continued use of vaccines with extended serotype coverage may further reduce IPD disease burden and mortality.

The New Era of Pneumococcal Vaccination in Adults: What Is Next?

Streptococcus pneumoniae remains the leading cause of community-acquired pneumonia in adults and bacterial meningitis in children worldwide. In addition to pneumonia, invasive pneumococcal diseases (IPDs), such as bacteremia and meningitis, pose a significant burden, particularly among older adults and individuals with underlying comorbidities. These diseases lead to substantial morbidity and mortality. Pneumococcal vaccination has been a cornerstone of disease prevention, reducing incidence and antimicrobial resistance. Recent advances in understanding S. pneumoniae epidemiology, genomic diversity, and the real-world impact of conjugate vaccines have driven the development and licensure of new-generation pneumococcal vaccines with expanded serotype coverage. Introducing 15-valent (PCV15), 20-valent (PCV20), and 21-valent (PCV21) conjugate vaccines has reshaped pneumococcal immunization strategies, particularly in adults, replacing previous sequential vaccine recommendations in many settings. In parallel, emerging epidemiological data and shifts in pneumococcal serotype distribution continue to influence vaccine policy decisions and immunization guidelines worldwide. In light of these advancements, adult pneumococcal vaccination recommendations continuously evolve to enhance protection in high-risk populations and optimize long-term immunity. This review provides an updated overview of the pneumococcal disease burden, the evolution of pneumococcal vaccines, and the latest immunization strategies in an expanding vaccine landscape. Additionally, we discuss future directions in pneumococcal vaccine development and the potential impact of novel vaccination approaches on public health outcomes.

Nationwide population-based surveillance of invasive pneumococcal disease in children in Japan (2014-2022): Impact of 13-valent pneumococcal conjugate vaccine and COVID-19 pandemic

BACKGROUND

Nationwide surveillance was conducted in Japan to clarify the status of pediatric invasive pneumococcal diseases (IPD) after introducing a 13-valent pneumococcal conjugate vaccine (PCV13).

METHODS

Detailed clinical and epidemiologic information of IPD cases in children aged <15 years was collected from 10 of 47 prefectures in Japan from January 2014 to December 2022. Streptococcus pneumoniae strains isolated from sterile body sites were analyzed including capsular serotypes, multi-locus sequence typing (MLST), and antimicrobial susceptibility testing. The serotype-specific IPD incidence was calculated by imputing the serotypes for missing isolates to serotypes assumed based on the distribution of known serotypes.

RESULTS

During the study period, 1033 IPD cases were reported. The incidence rate of total IPD in patients aged <5 years from 2014 to 2019 declined by 21.3 % compared with the rate from 2011 to 2013 before the introduction of PCV13. Compared with the incidence of total IPD from 2014 to 2019 and from 2020 to 2022, during the COVID-19 pandemic, the incidence of IPD among children aged <5 years declined by 49.7 %. In total, 932 IPD cases were identified as capsular serotypes. Among children aged <5 years, the most frequent serotype was 24F, followed by 15 A, 12F, 15C, 15B, and 10 A. Since 2014, after replacement with PCV13 in 2013, the rate of IPD by PCV13 minus PCV7 serotypes decreased, and non-PCV13 serotypes further increased. The serotype causing IPD in children aged <5 years, with PCV15-unique serotypes and PCV20-unique serotype were 8.6 % and 22.5 %, respectively. In terms of antimicrobial susceptibility, strains resistant to penicillin and cefotaxime decreased, whereas the meropenem non-susceptible strains increased in the post-PCV13 era.

CONCLUSION

PCV13 introduction and the COVID-19 pandemic have had a significant impact on pediatric IPD in Japan. It is important to continuously monitor the epidemiological characteristics of pediatric IPD after the introduction of PCV20.

Changes in the incidence, viral coinfection pattern and outcomes of pneumococcal hospitalizations during and after the COVID-19 pandemic

BACKGROUND

The incidence of pneumococcal pneumonia in the context of the Coronavirus Disease 2019 (COVID-19) pandemic, along with the real-world data on the ratio of non-invasive to invasive pneumococcal pneumonia, is an area that has not been thoroughly studied. The outcomes associated with coinfection of influenza and COVID-19 remain unknown. This study examined the incidence, demographics, coinfection with influenza and/or COVID-19, and clinical outcomes of pneumococcal hospitalizations in Hong Kong during the baseline, pandemic, and post-pandemic periods.

METHODS

Hospitalization records of individuals aged 18 years and above with pneumococcal disease from January 2015 to August 2024 were extracted from the territory-wide electronic medical record database. Pneumococcal disease was categorized into invasive pneumococcal pneumonia (IPP), invasive pneumococcal disease without pneumonia (IPDWP), and non-invasive pneumococcal pneumonia (NIPP), followed by univariate and multivariate analyses. Effects of coinfection with influenza and COVID-19 were analyzed.

RESULTS

The incidence of pneumococcal disease decreased during the COVID-19 pandemic but rebounded in the post-pandemic period. There were no significant changes in the distribution of pneumococcal serotypes across the three periods. The study revealed a strong positive correlation between monthly pneumococcal hospitalizations and the indicator of influenza activity, while the correlation with the COVID-19 indicator was weak. Additionally, strong positive correlations were observed between the indicator of influenza activity and influenza coinfections, as well as between the indicator of COVID-19 activity and COVID-19 coinfections. Multivariate analyses identified male gender, a higher comorbidity index, older age, invasive pneumococcal disease (IPP and IPDWP), coinfection with influenza and COVID-19, and hospitalization during the pandemic period as factors associated with adverse outcomes.

CONCLUSIONS

The study showcases changes in the epidemiology of pneumococcal disease during and after the COVID-19 pandemic. It highlights the adverse effects of influenza and COVID-19 coinfections on the outcomes of patients with pneumococcal disease and emphasizes the need to vaccinate vulnerable populations against these infections.

Impact of the COVID-19 pandemic on invasive pneumococcal disease in American Indian communities in the Southwest US

American Indian (AI) communities in the Southwest have a high burden of invasive pneumococcal disease (IPD) and COVID-19. Through laboratory-based surveillance, the impact of the pandemic on IPD incidence and serotype distribution was evaluated in two AI communities. IPD rates were lower during the pandemic (21.8 vs. 39.0/100 000 pre-pandemic). Rates increased in 2021 compared to 2020 but not to pre-pandemic levels. Cases with SARS-CoV-2 co-infection had a higher case fatality rate (45.2% vs. 17.6% without co-infection). No significant change in serotype distribution was observed. Continued surveillance in these communities is critical to understand the changing IPD burden as the pandemic evolves.

Incidence and severity of community acquired pneumonias in children before and after the COVID-19 pandemic

BACKGROUND

During the first year of the covid-19 pandemic the adoption of non-pharmacological interventions (NPI), resulted in a significant fall in the incidence of respiratory tract infections. However, after the relaxation of these restrictions some of these infections have returned. This study evaluates the incidence and severity of community acquired pneumonias (CAPs) in children before and after the onset of pandemic.

METHODS

Characteristics of CAPs admitted to Archbishop Makarios Hospital, between March 2016 and February 2023 were reviewed. Comparison was made between the first, second and third pandemic year, and the four pre-pandemic years.

RESULTS

The mean annual number of admissions in the pre-pandemic years was 32 and dropped to 11 during the first pandemic year. However, admissions increased again in the second year of the pandemic to 41 (increase by 28%), and this increase was sustained into the third year. The proportion of complicated pneumonias, approximately doubled, from 20% in the pre-pandemic years to 35% and 33% in the second and third pandemic year, respectively.

CONCLUSIONS

During the first year the use of NPIs appeared to have decreased the incidence of pneumonias. However, during the second and third pandemic years, an increase in the numbers and severity of pneumonias was noted.

Surveillance of Pediatric Invasive Bacterial Diseases in the Veneto Region: Epidemiological Trends and Outcomes over 17 Years (2007-2023)

Introduction: Invasive bacterial diseases (IBDs) such as meningitis and sepsis are significant public health concerns, particularly in pediatric populations. This study analyzes the incidence, outcomes, and bacterial serotype distribution of pediatric IBDs in the Veneto Region over 17 years. Methods: An observational study was conducted using data (2007-2023) from the surveillance system of the Veneto Region, including microbiologically confirmed cases in individuals < 18 years. Differences by age groups and trends were statistically assessed. Results: A total of 535 pediatric IBD cases were reported, with Streptococcus pneumoniae (54.6%), Neisseria meningitidis (19.6%), and Streptococcus agalactiae (13.5%) being the most common pathogens. Haemophilus influenzae infections were more commonly represented in infants under 1 year (41.5%), whereas S. pneumoniae and N. meningitidis were more frequent in the 1-4-year age group (40.8% and 37.1%, respectively). Sepsis was the most common clinical presentation (57.2%), followed by meningitis (36.3%). Serotype analysis revealed that S. pneumoniae serotype 3 was the most prevalent, while serogroup B dominated N. meningitidis cases. Temporal trends generally showed a decline in cases until 2019, a drop during the COVID-19 pandemic, and a subsequent resurgence in 2022-2023. Conclusions: Our research underscores the value of evidence-based epidemiology through robust surveillance systems in tracking IBD trends and serotype shifts, essential for guiding vaccination strategies and public health interventions. These insights highlight the effectiveness of vaccination programs and the necessity of ongoing monitoring to inform public health policies. Improved data integration and completeness are recommended to enhance surveillance accuracy.

Assessing the Impact of Pneumococcal Conjugate Vaccine Immunization Schedule Change From 3+0 to 2+1 in Australian Children: A Retrospective Observational Study

BACKGROUND

In mid-2018, the Australian childhood 13-valent pneumococcal conjugate vaccine schedule changed from 3+0 to 2+1, moving the third dose to 12 months of age, to address increasing breakthrough cases of invasive pneumococcal disease (IPD), predominantly in children aged >12 months. This study assessed the impact of this change using national IPD surveillance data.

METHODS

Pre- and postschedule change 3-dose 13-valent pneumococcal conjugate vaccine breakthrough cases were compared by age group, serotype, and clinical syndrome. Annual rates of breakthrough cases were calculated (per 100 000) using respective birth cohort sizes and 3-dose vaccine coverage. Using time-series modelling, observed IPD rates in children aged <12 years were compared to that expected if the 3+0 schedule were continued.

FINDINGS

Over 2012-2022, rate of 3-dose breakthrough cases in children aged >12 months was 2.8 per 100 000 (n = 557; 11 birth cohorts). Serotype 3 replaced 19A as predominant breakthrough serotype (respectively, 24% and 65% in 2013 to 60% and 20% in 2022) followed by 19F. In breakthrough cases, the most frequent clinical phenotype was bacteremic pneumonia (69%), with meningitis accounting for 3%-4%. In cohorts eligible for 2+1 versus 3+0 schedules, rate of breakthrough cases was lower for all vaccine serotypes, except type 3 (incidence rate ratio, 0.50 [95% confidence interval, .28-.84] and 1.12 [0.71-1.76], respectively). Observed compared to expected IPD was 51.7% lower (95% confidence interval, -60.9 to -40.7%) for vaccine serotypes, but the change for nonvaccine types was not significant 12% (-9.6 to 39.7).

INTERPRETATIONS

The 2+1 schedule is likely superior to 3+0 for overall IPD control, a finding that may be worth consideration for other countries considering or using 3+0 PCV schedules.

Invasive pneumococcal disease serotype 23B1 causing multifocal septic arthritis, myositis and retroperitoneal abscess

We describe a case of a previously healthy unvaccinated man in his 70s who developed penicillin-susceptible bacteraemic invasive pneumococcal disease due to non-vaccine serotype 23B with the unusual manifestations of multifocal myositis, intramuscular abscesses, polyarticular septic arthritis and synovitis. Blood cultures drawn prior to antibiotic therapy and culture of iliopsoas collection were helpful in making the diagnosis. At follow-up, he had persistent hip pain attributed to avascular necrosis of the head of femur, a possible late complication of his pyomyositis.

Comparison of next generation technologies and bioinformatics pipelines for capsular typing of Streptococcus pneumoniae

Whole genome sequencing (WGS)-based approaches for pneumococcal capsular typing have become an alternative to serological methods. In silico serotyping from WGS has not yet been applied to long-read sequences produced by third-generation technologies. The objective of the study was to determine the capsular types of pneumococci causing invasive disease in Catalonia (Spain) using serological typing and WGS and to compare the performance of different bioinformatics pipelines using short- and long-read data from WGS. All invasive pneumococcal pediatric isolates collected in Hospital Sant Joan de Déu (Barcelona) from 2013 to 2019 were included. Isolates were assigned a capsular type by serological testing based on anticapsular antisera and by different WGS-based pipelines: Illumina sequencing followed by serotyping with PneumoCaT, SeroBA, and Pathogenwatch vs MinION-ONT sequencing coupled with serotyping by Pathogenwatch from pneumococcal assembled genomes. A total of 119 out of 121 pneumococcal isolates were available for sequencing. Twenty-nine different serotypes were identified by serological typing, with 24F (n = 17; 14.3%), 14 (n = 10; 8.4%), and 15B/C (n = 8; 6.7%) being the most common serotypes. WGS-based pipelines showed initial concordance with serological typing (>91% of accuracy). The main discrepant results were found at the serotype level within a serogroup: 6A/B, 6C/D, 9A/V, 11A/D, and 18B/C. Only one discrepancy at the serogroup level was observed: serotype 29 by serological testing and serotype 35B/D by all WGS-based pipelines. Thus, bioinformatics WGS-based pipelines, including those using third-generation sequencing, are useful for pneumococcal capsular assignment. Possible discrepancies between serological typing and WGS-based approaches should be considered in pneumococcal capsular-type surveillance studies.

Safety and Immunogenicity of V114 in Preterm Infants: A Pooled Analysis of Four Phase Three Studies

BACKGROUND

Risk of invasive pneumococcal disease is 3-fold higher in preterm versus full-term infants. V114 is a 15-valent pneumococcal conjugate vaccine (PCV) containing the 13 serotypes in PCV13 plus 2 unique serotypes, 22F and 33F. A pooled subgroup analysis was performed in preterm infants (<37 weeks gestational age) enrolled in 4 pediatric phase 3 studies evaluating the safety and immunogenicity of different 4-dose regimens of V114 or PCV13.

METHODS

Healthy preterm infants were randomized 1:1 to receive V114/PCV13 in the 4 studies. Safety was evaluated as the proportion of participants with adverse events (AEs) following receipt of PCV. Serotype-specific antipneumococcal immunoglobulin G (IgG) geometric mean concentrations, IgG response rates and opsonophagocytic activity geometric mean titers were measured at 30 days postdose 3, pretoddler dose and 30 days postdose 4.

RESULTS

V114 and PCV13 were administered to 174 and 180 participants, respectively. Mean gestational age was 35.4 weeks (range: 27 - <37 weeks). Proportions of participants with AEs were comparable between vaccination groups; most AEs experienced were of short duration (≤3 days) and mild-to-moderate intensity. V114-elicited IgG geometric mean concentrations, IgG response rates and opsonophagocytic activity geometric mean titers were generally comparable to PCV13 for the 13 shared serotypes and higher for serotypes 22F and 33F at 30 days postdose 3 and postdose 4.

CONCLUSIONS

In preterm infants, V114 was well tolerated and induced comparable immune responses to PCV13 for the 13 shared serotypes and higher immune responses to serotypes 22F and 33F. Results support the use of V114 in preterm infants.

Changes in Invasive Pneumococcal Disease in the Paediatric Population in the Second COVID-19 Pandemic Year

Incidence of invasive pneumococcal disease (IPD) decreased worldwide in 2020, coinciding with the implementation of measures to reduce COVID-19 transmission. We evaluated the impact of the COVID-19 pandemic on healthcare demand and IPD in children in 2021 compared to the pre-pandemic period (2018-2019) and the early pandemic period (2020) in a study carried out during 2018-2021 in Catalonia. Incidence rates were compared by calculating the incidence rate ratio (IRR), and expressing percentage changes in IRR as (1-IRR)x100. Compared to 2018-2019, emergency room (ER) visits declined by 21% in 2021 (p < 0.001), mainly in the first quarter (-39%), and compared to 2020, ER visits increased by 22% in 2021 (p < 0.001), except in the first quarter. IPD incidence overall was 11.0 in 2018-2019 and 4.6 in 2021 (-58%, p < 0.001); the reduction in incidence was similar in the 0-4 age group and was higher in the first quarters. Compared to 2020, in 2021, IPD incidence decreased during the first quarter (-86%, p < 0.001), but increased from 0.0 to 1.2 in the second quarter (p = 0.02) and from 0.6 to 2.1 (p=0.03) in the fourth quarter. The decreased IPD incidence observed in 2021 compared to 2018-2019 (most especially in the first quarter) was greater than the decrease in healthcare demand and PCR test requests. Compared to 2020, IPD incidence decreased in the first quarter when a second state of alarm was in force. In 2021, compared to 2018-2019, there was a greater reduction in PCV13 serotypes than in non-PCV13 serotypes.

Trends in invasive bacterial diseases during the first 2 years of the COVID-19 pandemic: analyses of prospective surveillance data from 30 countries and territories in the IRIS Consortium

BACKGROUND

The Invasive Respiratory Infection Surveillance (IRIS) Consortium was established to assess the impact of the COVID-19 pandemic on invasive diseases caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and Streptococcus agalactiae. We aimed to analyse the incidence and distribution of these diseases during the first 2 years of the COVID-19 pandemic compared to the 2 years preceding the pandemic.

METHODS

For this prospective analysis, laboratories in 30 countries and territories representing five continents submitted surveillance data from Jan 1, 2018, to Jan 2, 2022, to private projects within databases in PubMLST. The impact of COVID-19 containment measures on the overall number of cases was analysed, and changes in disease distributions by patient age and serotype or group were examined. Interrupted time-series analyses were done to quantify the impact of pandemic response measures and their relaxation on disease rates, and autoregressive integrated moving average models were used to estimate effect sizes and forecast counterfactual trends by hemisphere.

FINDINGS

Overall, 116 841 cases were analysed: 76 481 in 2018-19, before the pandemic, and 40 360 in 2020-21, during the pandemic. During the pandemic there was a significant reduction in the risk of disease caused by S pneumoniae (risk ratio 0·47; 95% CI 0·40-0·55), H influenzae (0·51; 0·40-0·66) and N meningitidis (0·26; 0·21-0·31), while no significant changes were observed for S agalactiae (1·02; 0·75-1·40), which is not transmitted via the respiratory route. No major changes in the distribution of cases were observed when stratified by patient age or serotype or group. An estimated 36 289 (95% prediction interval 17 145-55 434) cases of invasive bacterial disease were averted during the first 2 years of the pandemic among IRIS-participating countries and territories.

INTERPRETATION

COVID-19 containment measures were associated with a sustained decrease in the incidence of invasive disease caused by S pneumoniae, H influenzae, and N meningitidis during the first 2 years of the pandemic, but cases began to increase in some countries towards the end of 2021 as pandemic restrictions were lifted. These IRIS data provide a better understanding of microbial transmission, will inform vaccine development and implementation, and can contribute to health-care service planning and provision of policies.

FUNDING

Wellcome Trust, NIHR Oxford Biomedical Research Centre, Spanish Ministry of Science and Innovation, Korea Disease Control and Prevention Agency, Torsten Söderberg Foundation, Stockholm County Council, Swedish Research Council, German Federal Ministry of Health, Robert Koch Institute, Pfizer, Merck, and the Greek National Public Health Organization.

Otorrhea bacterial profile, epidemiology before widespread use of the third-generation pneumococcal conjugate vaccine in French children, a prospective study from 2015 to 2023

OBJECTIVES

The aim of this study was to describe the bacterial profile of middle ear fluid from spontaneous perforation of the tympanic membrane (SPTM) prior to widespread utilization of third- generation pneumococcal conjugate vaccines (PCVs).

PATIENTS AND METHODS

From October 2015 to January 2023, children with SPTM were prospectively enrolled by pediatricians.

RESULTS

Among the 852 children with SPTM, 73.2% were less than 3 years old; more frequently than older children, they were and suffering from complex acute otitis media (AOM) (27.9%) and conjunctivitis (13.1%). In children under 3 years of age, NT Haemophilus influenzae (49.7%) was the main otopathogen isolated, particularly in those with complex AOM (57.1%). In children over 3 years of age, Group A Streptococcus accounted for 57%. In pneumococcal cases (25.1%), serotype 3 was the main serotype isolated (16.2%), followed by 23B (15.2%).

CONCLUSION

Our data from 2015 to 2023 represent a robust baseline preceding the widespread utilization of next-generation PCVs.

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

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

Streptococcus pneumoniae Serotype 23B Causing Asymptomatic Sinusitis Complicated by Endocarditis and Meningitis: Sequela of a Non-vaccine Serotype

We describe a rare case of a Streptococcus pneumoniae (S. pneumoniae) infection causing mitral valve endocarditis and bacterial meningitis in a previously healthy young adult male in his 20s who presented with altered mentation. Though our patient did not endorse any respiratory issues, we suspected the paranasal sinuses to have been the cryptic primary source of disseminated infection into the respiratory system and meninges due to incidental mucosal thickening being found on imaging. Blood and cerebrospinal fluid analyses and cultures revealed the proliferation of S. pneumoniae serotype 23B, despite our patient having previously received appropriate pneumococcal vaccinations in his childhood without delinquency. Ultimately, surgical replacement of the mitral valve, as well as a course of ceftriaxone, was indicated for this patient, in which full resolution of symptoms was achieved upon discharge.

Assessing Public Health Impact of Four Pediatric Pneumococcal Conjugate Vaccination Strategies in the Netherlands

INTRODUCTION

The 10-valent pneumococcal conjugate vaccine (PCV10, Synflorix) was introduced into the Dutch pediatric national immunization program (NIP) starting in 2011. However, there is substantial pneumococcal disease burden due to increases in non-PCV10 covered serotypes. Higher-valent vaccines for pediatrics (PCV13, PCV15, and PCV20) may alleviate much of the remaining disease burden upon implementation through broader serotype coverage. This article assesses the public health impact of different pediatric vaccination strategies (switching to PCV13, PCV15 or PCV20) versus maintaining PCV10 at different time intervals in the Netherlands.

METHODS

A population-based, decision-analytic model was developed using historical pneumococcal disease surveillance data to forecast future invasive pneumococcal disease (IPD), pneumonia, and otitis media (OM) cases over a 7-year period (2023-2029) under the following strategies: continued use of PCV10, switching to PCV13 in 2023, switching to PCV15 in 2023, and switching to PCV20 in 2024. Scenario analyses were performed to account for uncertainties in future serotype distributions, disease incidence reductions, and epidemiologic parameters.

RESULTS

Switching to PCV13 in 2023 was found to avert 26,666 cases of pneumococcal disease compared to continuing PCV10 over a 7-year period (2023-2029). Switching to PCV15 in 2023 was found to avert 30,645 pneumococcal cases over the same period. Switching to PCV20 once available in 2024 was estimated to avert 45,127 pneumococcal cases from 2024-2029. Overall conclusions were maintained after testing uncertainties.

CONCLUSIONS

For the Dutch pediatric NIP, switching to PCV13 in 2023 would be an effective strategy compared with continued use of PCV10 for averting pneumococcal disease cases. Switching to PCV20 in 2024 was estimated to avert the most pneumococcal disease cases and provide the highest protection. However, in the face of budget constraints and the undervaluation of prevention strategies, it remains challenging to implement higher valent vaccines. Further research is needed to understand the cost-effectiveness and feasibility of a sequential approach.

Persistence of Pneumococcal Carriage among Older Adults in the Community despite COVID-19 Mitigation Measures

Reported rates of invasive pneumococcal disease were markedly lower than normal during the 2020/2021 winter in the Northern Hemisphere, the first year after the start of the COVID-19 pandemic. However, little is known about rates of carriage of pneumococcus among adults during this period. Between October 2020-August 2021, couples in the Greater New Haven Area, USA, were enrolled if both individuals were aged 60 years and above and did not have any individuals under the age of 60 years living in the household. Saliva samples and questionnaires regarding social activities and contacts and medical history were obtained every 2 weeks for a period of 10 weeks. Following culture-enrichment, extracted DNA was tested using qPCR for pneumococcus-specific sequences piaB and lytA. Individuals were considered positive for pneumococcal carriage when Ct values for piaB were ≤40. Results. We collected 567 saliva samples from 95 individuals (47 household pairs and 1 singleton). Of those, 7.1% of samples tested positive for pneumococcus, representing 22/95 (23.2%) individuals and 16/48 (33.3%) households. Study participants attended few social events during this period. However, many participants continued to have regular contact with children. Individuals who had regular contact with preschool and school-aged children (i.e., 2 to 9 year olds) had a higher prevalence of carriage (15.9% versus 5.4%). Despite COVID-19-related disruptions, a large proportion of older adults continued to carry pneumococcus. Prevalence was particularly high among those who had contact with school-aged children, but carriage was not limited to this group. IMPORTANCE Carriage of Streptococcus pneumoniae (pneumococcus) in the upper respiratory tract is considered a prerequisite to invasive pneumococcal disease. During the first year of the COVID-19 pandemic, markedly lower rates of invasive pneumococcal disease were reported worldwide. Despite this, by testing saliva samples with PCR, we found that older adults continued to carry pneumococcus at pre-pandemic levels. Importantly, this study was conducted during a period when transmission mitigation measures related to the COVID-19 pandemic were in place. However, our observations are in line with reports from Israel and Belgium where carriage was also found to persist in children. In line with this, we observed that carriage prevalence was particularly high among the older adults in our study who maintained contact with school-aged children.

The effects of the COVID-19 pandemic on community respiratory virus activity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused substantial global morbidity and deaths, leading governments to turn to non-pharmaceutical interventions to slow down the spread of infection and lessen the burden on health care systems. These policies have evolved over the course of the COVID-19 pandemic, including after the availability of COVID-19 vaccines, with regional and country-level differences in their ongoing use. The COVID-19 pandemic has been associated with changes in respiratory virus infections worldwide, which have differed between virus types. Reductions in respiratory virus infections, including by influenza virus and respiratory syncytial virus, were most notable at the onset of the COVID-19 pandemic and continued in varying degrees through subsequent waves of SARS-CoV-2 infections. The decreases in community infection burden have resulted in reduced hospitalizations and deaths associated with non-SARS-CoV-2 respiratory infections. Respiratory virus evolution relies on the maintaining of a diverse genetic pool, but evidence of genetic bottlenecking brought on by case reduction during the COVID-19 pandemic has resulted in reduced genetic diversity of some respiratory viruses, including influenza virus. By describing the differences in these changes between viral species across different geographies over the course of the COVID-19 pandemic, we may better understand the complex factors involved in community co-circulation of respiratory viruses.

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.

Invasive pneumococcal surveillance to assess the potential benefits of extended spectrum conjugate vaccines (PCV15/PCV20) in older adults

The introduction of pneumococcal conjugate vaccines (PCV) into the childhood vaccination programme has reduced invasive pneumococcal disease (IPD). Although anticipated from data elsewhere, surveillance in Ireland has confirmed reductions in IPD amongst those ⩾65 years of age due to a decline of PCV serotypes in this age group. Currently, direct protection against IPD in the elderly is focused on immunisation with the 23-valent pneumococcal polysaccharide vaccine (PPV23). However, immunity may not be as effective as with PCV and, furthermore, PPV23 uptake is poor in Ireland. Hence, consideration should be given to providing a PCV to this age group.

Vaccination against Community-Acquired Pneumonia in Spanish Adults: Practical Recommendations by the NeumoExperts Prevention Group

In the adult population, community-acquired pneumonia (CAP) is a serious disease that is responsible for high morbidity and mortality rates, being frequently associated with multidrug resistant pathogens. The aim of this review is to update a practical immunization prevention guideline for CAP in Spain caused by prevalent respiratory pathogens, based on the available scientific evidence through extensive bibliographic review and expert opinion. The emergence of COVID-19 as an additional etiological cause of CAP, together with the rapid changes in the availability of vaccines and recommendations against SARS-CoV-2, justifies the need for an update. In addition, new conjugate vaccines of broader spectrum against pneumococcus, existing vaccines targeting influenza and pertussis or upcoming vaccines against respiratory syncytial virus (RSV) will be very useful prophylactic tools to diminish the burden of CAP and all of its derived complications. In this manuscript, we provide practical recommendations for adult vaccination against the pathogens mentioned above, including their contribution against antibiotic resistance. This guide is intended for the individual perspective of protection and not for vaccination policies, as we do not pretend to interfere with the official recommendations of any country. The use of vaccines is a realistic approach to fight these infections and ameliorate the impact of antimicrobial resistance. All of the recently available scientific evidence included in this review gives support to the indications established in this practical guide to reinforce the dissemination and implementation of these recommendations in routine clinical practice.

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.

Shionone-Targeted Pneumolysin to Ameliorate Acute Lung Injury Induced by Streptococcus pneumoniae In Vivo and In Vitro

Streptococcus pneumoniae (S. pneumoniae), as a Gram-positive bacterium, can cause severe bacterial pneumonia, and result in high morbidity and mortality in infected people. Meanwhile, isolated drug-resistant S. pneumoniae is growing, which raises concerns about strategies for combatting S. pneumoniae infection. To disturb S. pneumoniae pathogenicity and its drug-resistance, developing novel anti-infective strategies or compounds is urgent. In this study, the anti-infective effect of shionone was explored. A minimum inhibitory concentration (MIC) assay and growth curve determination were performed to evaluate the effect of the tetracyclic triterpenoid compound shionone against S. pneumoniae. Hemolysis tests, western blotting, oligomerization inhibition assays, and molecular docking were carried out to explore the anti-infective mechanism of shionone. Moreover, the protective effect of shionone was also confirmed in a mousepneumonia model. The results showed that the excellent hemolytic inhibitory activity of shionone was observed at less than 8 μg/mL. Meanwhile, shionone could disturb the oligomerization of pneumolysin (PLY) but did not interfere with PLY expression at less than 4 μg/mL. Molecular docking suggested that shionone targeted the ASP-59, ILE-60, THR-57, PHE-344, and ASN-346 amino acid sites to reduce S. pneumoniae pathogenicity. Furthermore, shionone alleviated lung histopathologic injury and decreased lung bacterial colonization in vivo. The above results showed that shionone could bind to the PLY active pocket under the concentrations of 8 μg/mL and neutralize PLY hemolysis activity to reduce S. pneumoniae pathogenicity in vitro and in vivo.

Increased Incidence of Invasive Pneumococcal Disease among Children after COVID-19 Pandemic, England

During July–December 2021, after COVID-19 restrictions were removed in England, invasive pneumococcal disease incidence in children <15 years of age was higher (1.96/100,000 children) than during the same period in 2020 (0.7/100,000 children) and in prepandemic years 2017–2019 (1.43/100,000 children). Childhood vaccine coverage should be maintained to protect the population.

Pathogen- and Type-Specific Changes in Invasive Bacterial Disease Epidemiology during the First Year of the COVID-19 Pandemic in The Netherlands

COVID-19 control measures have resulted in a decline in invasive bacterial disease caused by Neisseria meningitidis (IMD), Streptococcus pneumoniae (IPD), and Haemophilus influenzae (Hi-D). These species comprise different serogroups and serotypes that impact transmissibility and virulence. We evaluated type- and pathogen-specific changes in invasive bacterial disease epidemiology in the Netherlands during the first year of the SARS-CoV-2 pandemic. Cases were based on nationwide surveillance for five bacterial species with either respiratory (IMD, IPD, Hi-D) or non-respiratory (controls) transmission routes and were compared from the pre-COVID period (April 2015−March 2020) to the first COVID-19 year (April 2020−March 2021). IMD, IPD, and Hi-D cases decreased by 78%, 67%, and 35%, respectively, in the first COVID-19 year compared to the pre-COVID period, although effects differed per age group. Serogroup B-IMD declined by 61%, while serogroup W and Y-IMD decreased >90%. IPD caused by serotypes 7F, 15A, 12F, 33F, and 8 showed the most pronounced decline (≥76%). In contrast to an overall decrease in Hi-D cases, vaccine-preventable serotype b (Hib) increased by 51%. COVID-19 control measures had pathogen- and type-specific effects related to invasive infections. Continued surveillance is critical to monitor potential rebound effects once restriction measures are lifted and transmission is resumed.