Post-marketing Safety Surveillance of 23-Valent Pneumococcal Polysaccharide Vaccine Administered Alone and Concomitantly with Influenza Vaccine in Individuals Aged 2 Years and Older in China

Introduction This phase IV study aimed to evaluate the safety of the 23-valent pneumococcal polysaccharide vaccine (PPV23) in individuals aged 2 years and older through active and passive surveillance. Methods Safety data were collected from May 2022 to March 2024 through 28-day post-vaccination active surveillance via active follow-up and 1-year passive surveillance via the Chinese National Adverse Events Following Immunization (AEFI) Information System (CNAEFIS). Adverse drug reactions (ADRs) via active follow-up and AEFIs via CNAEFIS were analyzed by age, health status, and co-administration status. Results A total of 19,267 participants received a single dose of PPV23, including 2977 under active surveillance and 16,290 under passive surveillance. In active surveillance, the overall incidence of ADRs was 1.81%, mostly mild and self-limiting, with rates of 1.76% in children (2–17 years), 2.28% in adults (18–59 years), and 1.67% in older adults (60 years and older). The incidence was 1.79% among healthy participants and 1.92% among participants with underlying medical conditions, and the incidence was 1.01% following PPV23 alone and 4.96% after co-administration with influenza vaccines. Passive surveillance identified 60 AEFI case reports (368 per 100000 doses), all occurring within 7 days of vaccination. No serious adverse event or serious AEFI were reported. Conclusion The PPV23 showed a favorable safety profile in all age groups, regardless of health status or co-administration with influenza vaccines. These findings support the use of PPV23 and provide evidence for its co-administration with influenza vaccines. ClinicalTrials.gov Identifier NCT07071701. Retrospectively registered.