[Efficacy evaluation after 5 years of inoculation of 23 valent pneumococcal polysaccharide vaccine for the elderly aged 60 years old and above in Shanghai during 2013-2018].

Objective: To evaluate the efficacy of 23 valent pneumococcal polysaccharide vaccine (PPV23) inoculation against community-acquired pneumonia (CAP) among the elderly aged 60 years old and above in Shanghai. Methods: A prospective cohort study was conducted using a stratified random sampling from October 2013, in which 1 214 and 2 387 elderly people aged 60 and above were selected as the inoculation group and control group, respectively. And a unified questionnaire was used to investigate the basic information of the subjects in the inoculation group and the control group. From October 2013 to December 2018, the subjects were followed up at home or by telephone for a total of 20 times, mainly for whether they had CAP during the observation period. Multivariate logistic regression model was used to calculate RR and 95%CI of CAP incidence between inoculation group and control group for comparing. Results: There were 556 males (45.8%) in the inoculation group and 1 012 males (42.4%) in the control group. And the incidence density of CAP in the inoculation group was lower than that of the control group (0.848/100 person-years vs. 1.452/100 person-years), and the vaccine protection rate was 41.6%, with a statistically significant difference ［RR (95%CI)= 0.584 (0.428-0.790), P<0.001］. After adjusting for age, RR (95%CI) was 0.699 (0.507-0.956), and the difference was still statistically significant (P=0.025).Further stratified analysis showed that the vaccine protective rates of PPV23 in the 60-69 year-old group, the 70-79 year-old group and the ≥80 year-old group were 36.7%, 21.6% and 26.0%, respectively, but only in the 60-69 year-old group showed statistical difference (RR=0.633, 95%CI=0.399-0.990, P=0.045). Conclusion: To a certain extent, the incidence of CAP can be reduced by inoculation of PPV23 in elderly population aged 60 and above in Shanghai, and it should be further recommended in elderly population of low age.