A vaccine for enterovirus 71 ( EV71 ) is needed to address the high burden of disease associated with infection. Researchers have assessed the efficacy, safety, immunogenicity, antibody persistence, and immunological correlates of an inactivated alum-adjuvant EV71 vaccine.
Investigators did a randomised, double-blind, placebo-controlled, phase 3 trial. Healthy children aged 6-35 months from four centres in China were randomly assigned ( 1:1 ) to receive vaccine or alum-adjuvant placebo at day 0 and 28.
Primary endpoints were EV71-associated hand, foot, and mouth disease ( HFMD ) and EV71-associated disease during the surveillance period from day 56 to month 14, analysed in the per-protocol population.
10245 participants were enrolled and assigned: 5120 to vaccine versus 5125 to placebo. 4907 ( with three cases of EV71-associated HFMD and eight cases of EV71-associated disease ) versus 4939 ( with 30 cases of EV71-associated HFMD and 41 cases of EV71-associated disease ) were included in the primary efficacy analysis.
Vaccine efficacy was 90.0% against EV71-associated HFMD ( p=0•0001 ) and 80.4% against EV71-associated disease ( p less than 0.0001 ).
Serious adverse events were reported by 62 of 5117 ( 1.2% ) participants in the vaccine group versus 75 of 5123 ( 1.5% ) in the placebo group ( p=0.27 ). Adverse events occurred in 3644 ( 71.2% ) versus 3603 ( 70.3%; p=0.33 ).
In conclusion, EV71 vaccine provides high efficacy, satisfactory safety, and sustained immunogenicity. ( Xagena )
Zhu FC et al, The Lancet 2013; 381: 2024-2032