Higher valency pneumococcal conjugate vaccines (PCV15 and PCV20) have been developed to address the disease burden of current non-vaccine serotypes. This review describes the epidemiological characteristics of serotypes beyond PCV13 (serotypes 8, 10A, 11A, 12F, 15B/C, 22F, and 33F; PCV20nonPCV13 serotypes). Peer-reviewed studies published between 1 January 2010 (the year PCV13 became available) and 18 August 2020 were systematically reviewed (PROSPERO number: CRD42021212875). Data describing serotype-specific outcomes on disease proportions, incidence, severity, and antimicrobial non-susceptibility were summarized for individual and aggregate PCV20nonPCV13 serotypes by age group and by type and duration of pediatric PCV immunization program. Of 1168 studies, 127 (11%) were included in the analysis. PCV20nonPCV13 serotypes accounted for 28% of invasive pneumococcal disease (IPD), although the most frequent serotypes differed between children (10A, 15B/C) and adults (8, 12F, 22F). In children, serotype 15B/C tended to be more frequently associated with pneumococcal meningitis and acute otitis media; in adults, serotype 8 was more frequently associated with pneumonia and serotype 12F with meningitis. Serotypes 10A and 15B/C in children and 11A and 15B/C in adults were often associated with severe IPD. Serotype 15B/C was also among the most frequently identified penicillin/macrolide non-susceptible PCV20nonPCV13 serotypes. These results could inform decision making about higher valency PCV choice and use.

Background: To guide decision-making on immunisation programmes for ageing adults in Europe, one of the aims of the Vaccines and InfecTious diseases in the Ageing popuLation (IMI2-VITAL) project is to assess the burden of disease (BoD) of (potentially) vaccine-preventable diseases ((P)VPD). We aimed to identify the available data sources to calculate the BoD of (P)VPD in participating VITAL countries and to pinpoint data gaps. Based on epidemiological criteria and vaccine availability, we prioritized (P) VPD caused by Extra-intestinal pathogenic Escherichia coli (ExPEC), norovirus, respiratory syncytial virus, Staphylococcus aureus, and pneumococcal pneumonia. Methods: We conducted a survey on available data (e.g. incidence, mortality, disability-adjusted life years (DALY), quality-adjusted life years (QALY), sequelae, antimicrobial resistance (AMR), etc.) among national experts from European countries, and carried out five pathogen-specific literature reviews by searching MEDLINE for peer-reviewed publications published between 2009 and 2019. Results: Morbidity and mortality data were generally available for all five diseases, while summary BoD estimates were mostly lacking. Available data were not always stratified by age and risk group, which is especially important when calculating BoD for ageing adults. AMR data were available in several countries for S. aureus and ExPEC. Conclusion: This study provides an exhaustive overview of the available data sources and data gaps for the estimation of BoD of five (P) VPD in ageing adults in the EU/EAA, which is useful to guide pathogen-specific BoD studies and contribute to calculation of (P)VPDs BoD.

Respiratory infections cause substantial morbidity and mortality in older adults and other at-risk adult populations. Despite the availability of effective vaccines, adult vaccination coverage remains suboptimal. This narrative review examines strategies designed to improve vaccine uptake among non-pregnant adults aged ≥18 years and inform future adult vaccination strategies. We conducted a targeted literature search using keywords for vaccination, respiratory diseases, strategy/program/implementation, and adults in PubMed database and CDC, WHO, and ECDC websites, between 2014 and 2024. A snowball search of literature reviews and key references was also performed to identify additional relevant studies. Eligible publications focused on vaccination strategies against influenza, COVID-19, and pneumococcal disease targeting non-pregnant adults (≥18 years). We categorized the strategies by intervention type to describe their influence on vaccination campaigns and vaccine uptake/coverage. We included 45 publications, encompassing strategies focused on individual decision-making, healthcare system functions, and national policy. Educational and awareness interventions (such as healthcare worker/provider recommendations during consultation, phone calls, letters, text messages, and social media outreach) reportedly raised vaccination rates. Access-related factors, including convenient vaccination sites and free or subsidized vaccines, were reported to be important factors in improving coverage in underserved communities. Within healthcare settings, strategies such as continuous vaccine provider training and workflow/process optimization were shown to enhance vaccination delivery. At the local or national policy levels, legislation governing program targets shaped immunization efforts and facilitated collaborations and partnerships to expand campaign reach. The findings may inform policymakers and public health/immunization practitioners in designing context-specific immunization initiatives that effectively reach adult populations.