Protective effect of PCV13 against all-cause hospitalized pneumonia in children in Beijing, China: real-world evidence

The study evaluated the protective effect of 13-valent pneumococcal polysaccharide conjugate vaccine (PCV13) against all-cause hospitalized pneumonia in children in Beijing.Based on the vaccination record and inpatient medical record database of Beijing, children born in 2017 in Beijing, matched by age, gender, and district of the children with the ratio of 1:4, were selected as the vaccinated and unvaccinated groups according whether if vaccinated with PCV13. The incidence rate and 95 % confidence interval (95 %CI), vaccine effectiveness (VE) and direct medical costs of all-cause hospitalized pneumonia were calculated and compared within the same period of 12 months, 18 months, 24 months and 30 months after the birth of the child.The decreased incidence rates of all-cause hospitalized pneumonia were observed at the four points in the PCV13 vaccinated group compared to the unvaccinated group, which were significant at the points of 12 months (0.42 % vs. 0.72 %, P = 0.001), 18 months (0.90 % vs. 1.26 %, P = 0.002) and 24 months (1.37 % vs. 1.65 %, P = 0.046). The VE of PCV13 against all-cause hospitalized pneumonia within 12 months was the highest as 41.9 % (95 % CI 19.6 %, 58.0 %), followed by 29.3 % (95 % CI 11.4 %, 43.5 %) within 18 months, 17.1 % (95 % CI 0.3 %, 31.1 %) within 24 months and it almost disappeared within 30 months. The VE of 4-dose vaccination within 18 months and 24 months were 39.9 % (95 % CI 20.3 %, 54.7 %) and 27.2 % (95 % CI 8.6 %, 42.0 %), respectively. The median hospitalization cost of the children in the vaccinated group was higher at the four points but without significance.PCV13 had a certain protective effect on all-cause hospitalized pneumonia, and the booster immunization strategy had the best protective effect with great public health significance to enter the immunization program.