[Evaluation of the anti-neuraminidase antibodies in clinical trials of the live influenza vaccine of the A(H5N2) subtype].

In the current study, we evaluated the neuraminidase-inhibition (NI) antibodies among volunteers during the phase I and phase II of the clinical trials of a monovalent live attenuated influenza vaccine (LAIV) A/17/duck/ Potsdam/86/92(H5N2). The reassortant influenza virus RN2/57-human A(H7N2) containing neuraminidase (NA) from the A/Leningrad/134/17/57(H2N2) was used in NI test. It was shown that two doses of the monovalent LAIV A(H5N2) led to a statistically significant increase in the NI antibodies to vaccine strain NA. More than twofold increase in antibodies was obtained among 19.5-33.3% of vaccinated. The microneutralization test and NI assay results coincidence in the same pairs of sera of the vaccinated volunteers was 73.2%, suggesting thus a statistically significant interdependence between the values of increase in antibodies revealed in both tests (p = 0.04).