Post-marketing safety surveillance conducted in Korea (2008-2013) following the introduction of the rotavirus vaccine, RIX4414 (Rotarix™)

Purpose: According to regulations from the Ministry of Food and Drug Safety in Korea, additional safety information on the use of Rotarix™ vaccine (RIX4414; GSK, Belgium) in ≥3000 evaluable Korean infants was required following vaccine registration. In order to comply with these regulations, we conducted a 6-year open, non-comparative, multicenter post-marketing surveillance (NCT00750893). Methods: During this time, the original lyophilized vaccine formulation of RIX4414 was replaced by a liquid formulation. Healthy infants aged ≥6 weeks were enrolled and given 2 doses of the RIX4414 vaccine, separated by an interval of ≥4 weeks. The overall incidence of adverse events (AEs) (expected and unexpected) was then assessed for up to 30 days along with the incidence of serious adverse events (SAEs). Adverse drug reactions (ADRs: any AE whose causality to the drug could not be ruled out) were identified. Results: A total of 3040 children (mean age: 9.55 weeks) were analyzed. One or more expected AE was experienced by 30.5% infants and 8.6% had an ADR. The most commonly seen expected AE was irritability (14.0%). One or more unexpected AE was seen in 32.5% infants and 3.1% experienced an ADR. The most commonly seen unexpected AE was upper respiratory tract infection (8.7%). Of 34 SAEs recorded in 24 subjects, none were related to vaccination. Conclusions: We conclude that this 6-year surveillance showed both formulations of RIX4414 to have acceptable safety profiles when administered to Korean infants according to local prescribing recommendations and current clinical practice.