Preventive effects of 23-valent pneumococcal polysaccharide vaccine on community-acquired pneumonia hospitalization in older individuals in China: A case-control study

The effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPSV23) against hospitalization risk due to all-cause community-acquired pneumonia (CAP) in older individuals in China is limited. A hospital-based case-control study was conducted on this issue in Suzhou City, Jiangsu Province, China. Cases were individuals who were newly diagnosed with CAP based on International Classification of diseases 10 (ICD10 code: J15.902, J15.903, J13.x00 × 001) from January 2023 to June 2023, while patients with other respiratory tract infections were the control group. The vaccination data of PPSV23 was obtained from Suzhou Center for Disease Control and Prevention. The results showed CAP group had a lower vaccination rate of PPSV23 within last 5 years than controls (3.27% <i>vs</i>. 4.81%). Both the severe CAP and non-severe CAP groups had lower vaccination rates of PPSV23 than controls. Logistic regression demonstrated that PPSV23 vaccination within 5 years in individuals aged ≥60 years prevented 26.7% hospitalization risks of all-cause CAP, with adjusted OR of 0.733 (95% CI = 0.605-0.887). PPSV23 vaccination could prevent 25.2% (adjusted OR = 0.748, 95% CI = 0.616-0.909) and 44.0% (adjusted OR = 0.560, 95% CI = 0.309-1.012) hospitalization risks due to non-severe CAP and severe CAP, respectively. PPSV23 vaccination is effective in reducing hospitalization risk due to CAP in older individuals.