Recommendations and guidance for pneumococcal vaccination for adults in Taiwan

Streptococcus pneumoniae remains a global health concern, causing diseases from sinusitis, otitis media, to invasive pneumococcal diseases (IPD), such as bacteremia, bacteremic pneumonia, empyema, and meningitis. Key IPD risk factors include age under five or over 50 years, chronic medical conditions, and lifestyle factors. In Taiwan, IPD incidence has declined following national immunization program. However, morbidity and mortality remain substantial, particularly among older adults. There are two types of pneumococcal vaccines, polysaccharide conjugate vaccines (PCV) and pneumococcal polysaccharide vaccines (PPSV). These vaccines target specific IPD serotypes but may lead to serotype replacement. In Taiwan, the available/forthcoming vaccines include PCV13, PCV15, PCV20, PCV21, and PPSV23, with numbers indicating serotype coverage. This guidance, developed and endorsed by eight national academic societies, serves as an adjunct to the Taiwan Advisory Committee on Immunization Practices recommendations. Using the GRADE framework, it provides evidence-based recommendations for adult pneumococcal vaccination. It emphasizes health promotion to assist healthcare professionals in vaccine selection tailored to current local epidemiology and individual vaccination history. A shared decision-making approach is encouraged, considering individual vulnerabilities, exposure risks, and lifestyle factors. This guidance addresses optimal timing, dosing schedules, coadministration, and safety; grounded in immunological evidence on efficacy, effectiveness, and immunogenicity. In recognition of feasibility of implementation, single-dose PCV20 or PCV21 is proposed as a simplified alternative to complex sequential strategies. However, PCV21 is recommended only where PCV7 serotypes are well controlled or no longer prevalent. This guidance reflects evolving pneumococcal vaccination strategies in response to serotype dynamics and availability of higher-valency conjugate vaccines.