Effectiveness of pentavalent rotavirus vaccine — a propensity score matched test negative design case-control study using electronic health records in three provinces of China

Background. Our study aimed to evaluate vaccine effectiveness (VE) of a live oral pentavalent rotavirus vaccine (RotaTeq, RV5) among < 5-year-old children in three provinces of China via a propensity score matched test negative design case-control study. Methods. We used electronic health records and person-matched immunization information system data to obtain information on acute gastroenteritis (AGE) cases in Guangdong, Beijing, and Hubei provinces evaluated for AGE in emergency department settings and tested for rotavirus (RV) infection during 2020–2024. RV positive cases were propensity-score matched with RV negative subjects on age, visit month, and province. Primary outcomes were medically-attended RVGE infection (inpatient or outpatient), outpatient-only medically-attended RVGE, and RVGE hospitalization. VE was estimated with logistic regression as (1-OR)×100%. Results. The study included 27 472 children with AGE aged 8 weeks to 4 years at the time of the visit; 7.98% (2 192) were rotavirus positive. After propensity score matching of 2 controls for each case, VE (95% confidence interval, CI ) of 1–2 and 3 doses of RV5 against infection were 57.6% (39.8%, 70.2%) and 67.2% (60.3%, 72.9%), respectively. Among children who received a third dose < 5-months-old, 3-dose VE decreased from 70.4% (53.9%, 81.1%) (< 5 months) to 65.4% (49.8%, 76.1%) (5 months - <1 year), and to 63.0% (49.1%, 73.0%) (≥ 1 year). Among children who received a third dose ≥ 5-months-old, 3-dose VE decreased from 69.3% (45.9%, 82.6%) (< 5 months) to 61.7% (44.2%, 73.8%) (≥ 1 year). Three-dose VE was 69.4% (41.3%, 84.0%) against hospitalization and 57.5% (38.9%, 70.5%) against outpatient RVGE. Conclusions. Three doses of RV5 provided highest protection against RVGE among < 5-year-old children. Three-dose VE decreased by time since the third dose in children who received a third dose at < 5-months-olds, and remained > 61% ≥1 year after the third dose. VE was higher against RVGE hospitalization than outpatient RVGE.