2700. Evaluation of 10- and 13-Valent Protein Conjugate Pneumococcal Vaccine Effectiveness for Children in Korea

BACKGROUND: Pneumococcal vaccination for infants was introduced to the mandatory National Immunization Program (NIP) of Korea in May 2014. Both 10- and 13-valent protein conjugated vaccines (PCV) have been in use with 3 + 1 dose schedule. We assessed the vaccine effectiveness in protecting children from all-cause pneumonia (ACP), pneumococcal pneumonia (PP), invasive pneumococcal diseases (IPD), and acute otitis media (AOM). METHODS: The birth cohort of children born between 2013 and 2015 was identified from the national population registry for retrospective observation. Vaccination status was confirmed through NIP registry by Korean Centers for Disease Control and Prevention, and disease occurrence was detected through the National Health Insurance System. Children who finished at least 3-doses of PCV were classified vaccinated while who did not receive any type of pneumococcal vaccine until study end were classified unvaccinated. The outcome of interest was hospital admission from any of pneumococcal infections among ACP, PP, IPD or AOM. After adjusting for high risk and underlying conditions, the vaccine effectiveness (VE) was calculated with Cox regression. VE of different valent PCV was also compared within fully vaccinated (4-doses) children. RESULTS: A total of 1,243,432 children were included. Fifty-one percent of children were boys and median age was 30-months. Ninety-eight percent were vaccinated and 89% of them were fully vaccinated. The incidence (per 100,000 person-years) of ACP was 10,982 in vaccinated and 9,276 in unvaccinated, and that of IPD and AOM were 1.0 vs 1.5 and 45.7 vs 31.3, respectively. The vaccine had protective effect for ACP (VE 20.2% [95% CI 19.5–20.9]), PP (VE 25.5% [95% CI 21.1–29.6]), IPD meningitis (VE 93.6% [95% CI 27.1–99.4]) and AOM (VE 4.6% [95% CI 4.1–5.1]). When fully vaccinated with PCV10, compared with PCV13, it was statistically more protective against ACP (VE 22.7% vs. 19.6%, P = 0.033) and PP (VE 50.8% vs. 21.3%, P < 0.001) but not different against AOM (VE 4.2% vs. 6.0%, P = 0.53). CONCLUSION: Four-doses of PCV strategy for children in current mandatory NIP is effective for protecting the vaccinated from ACP, PP, IPD, and AOM. DISCLOSURES: All authors: No reported disclosures.