Detection of anti-neuraminidase antibody in preclinical and clinical studies of live influenza vaccine

摘要

The aim of this study is to evaluate antibody response to influenza virus neuraminidase (NA) following immunization with live attenuated influenza vaccine (LATV). We adjusted the peroxidase-linked lectin micro-procedure previously reported by Lambre, et al. (1990) to assay neuraminidase inhibition (NI) antibody in sera taken from immunized mice and from human subjects in a clinical trial. For the assay, we prepared the A(H7N1) reassortant virus containing the NA of A/California/07/2009 (H1N1) and the hemagglutinin (HA) of A/equine/Pra-gue/l/56(H7N7). In addition, we used an NA-specific IgG ELISA assay to test sera from immunized mice and volunteers. In mice, one dose of LAIV induced NI antibody of a geometric mean titer (GMT) of 31-7, compared to 10-6 in the control group. GMT of NI from human subjects who received two doses of pandemic A(H1N1) were significantly higher than pre-vaccination titers. In unvaccinated human subjects, NA-specific cross-reactive antibodies to pandemic A(H1N1) were detected more often than cross-reactive antibodies to HA.