2713. Effectiveness of 23-Valent Pneumococcal Polysaccharide Vaccine in Korean National Population Cohort over 65 Years Old

BACKGROUND: Twenty-three valent pneumococcal polysaccharide vaccine (PPSV) has been introduced to the National Immunization Program (NIP) for adults aged 65 years and older in Korea since 2013. We describe the effectiveness evaluation of PPSV among adults against pneumococcal infections including all-cause pneumonia (ACP), pneumococcal pneumonia (PP), and invasive pneumococcal diseases (IPD) using national population cohort. METHODS: Vaccination records of the national population, aged 65 years and older, from NIP registry by Korea Centers for Disease Control and Prevention (KCDC) were matched to their corresponding medical records by National Health Insurance Service (NHIS) for retrospective cohort analysis. Adults vaccinated with 1-dose PPSV between 2013 and 2016 were compared with those non-vaccinated. Primary outcomes were hospitalization due to ACP, PP, and IPD. Vaccine effectiveness (VE) adjusted for high risk and underlying conditions was calculated as one minus hazard rate ratio (HR) using Cox regression. RESULTS: Records of 6,743,002 cohort members were included. Forty-three percent were male, and median age was 75-years. Among the cohort, 3,425,949 (51%) were vaccinated during the study period. Incidence (per 100,000 person-years) of each disease in vaccinated and unvaccinated, respectively, was 2,184 and 1,584 for ACP, 8.9 and 5.4 for PP, and 1.6 and 1.9 for IPD. VE against IPD was 41.7% (95% CI 28.8–52.3) and against IPD sepsis was 53.5% (95% CI 39.8–64.0). PPSV was also protective against ACP with VE 7.2% (95% CI 6.6–7.8). When stratified by age-group, adults aged 65–74 years were better protected from ACP (VE 16.5% [95% CI 15.6–17.3]) compared with older adults aged 75 years or older (VE –0.4% [95% CI –1.2 to 0.4]), while VE was higher in older adults against IPD (VE 47.6% [95% CI 32.4–59.4]) and IPD sepsis (VE 54.9 [95% CI 38.4–66.9]) than in 65–74 years group (IPD VE 30.4% [95% CI 3.4–49.9]; sepsis VE 49.0% [95% CI 19.7–67.6]). CONCLUSION: Single-dose PPSV strategy for adults in general population is protective against PCV, IPD, and IPD sepsis. DISCLOSURES: All authors: No reported disclosures.