Effectiveness of enterovirus A71 vaccine against pediatric HFMD and disease profile of post-vaccination infection.

Vaccination has been proven effective against infection with enterovirus A71 (EV-A71) in clinical trials, but vaccine effectiveness in real-world situations remains incompletely understood. Furthermore, it is not clear whether previous vaccination will result in symptom attenuation among post-vaccinated cases. Based on long-term data extracted from the only designed referral hospital for infectious diseases, we used a test-negative case-control design and multivariate logistic regression models to analyze the effectiveness of EV-A71 vaccine against hand, foot and mouth disease (HFMD). And then, generalized linear regression models were used to evaluate the associations between prior vaccination and disease profiles. We selected 4883 inpatients for vaccine efficacy estimations and 2188 inpatients for disease profile comparisons. Vaccine effectiveness against EV-A71-induced HFMD for complete vaccination was 63.4 % and 51.7 % for partial vaccination. The vaccine effectiveness was higher among cases received the first dose within 12 months. No protection was observed against coxsackievirus (CV) A6-, CV-A10- or CV-A16-associated HFMD among children regardless of vaccination status. Completely vaccinated cases had shorter hospital stay and disease course compared to unvaccinated cases (P < 0.05). These findings reiterate the need to continue the development of a multivalent vaccine or combined vaccines, and have implications for introducing optimized vaccination strategies. [ABSTRACT FROM AUTHOR]