Active surveillance for safety of enterovirus 71 inactivated vaccine

ObjectiveTo evaluate the safety of enterovirus 71 inactivated vaccine.

MethodsThe children aged 6−47 months in Jinhua, Zhejiang province, were selected as the research subjects, active surveillance was conducted in forms of face to face interview and telephone interview, and the adverse reactions occurred during 0−30 days after vaccination were recorded.

ResultsA total of 6 084 children were included in the study, and 9 090 vaccination doses were actively monitored, and 59 children were found to have adverse reactions, the incidence rate was 649.06 per 100 000 doses, and 96.61% of the adverse reactions occurred within 0−3 days after vaccination. The main adverse reactions were fever (72.88%), diarrhea (27.12%) and nausea and vomiting (10.17%), and the outcome was good. Fifteen cases with grade ≥3 reactions were cured in the observation period. There was no significant differences in gender, age, time and dose specific incidences of adverse reactions (P>0.05). There was significant difference in the incidence of adverse reactions among different vaccines (P<0.05), but no significant difference in the incidence of grade ≥3 adverse reactions (P>0.05). The results of logistic regression analysis showed that the type of vaccine was the influencing factor of adverse reaction.

ConclusionThe incidence of adverse reactions within 0−30 days after enterovirus 71 inactivated vaccine immunization was relatively low, which was related with the type of vaccine.