OMOLOGICAL AND HETEROLOGICAL ANTIBODY AND T CELL IMMUNE RESPONSES TO LIVE ATTENUATED INFLUENZA VACCINE A (H5N2) AND A (H7N3)

Abstract

From the beginning of 21th century outbreaks of H5, H7 and H9 avian flu are registered from time to time. These viruses are considered as one of the possible causes of the next pandemia. The development of avian influenza vaccines is one of the WHO priorities. The aim of this work was to study antibody and cellular immune responses to avian A (H5N2) and A (H7N3) live attenuated influenza vaccines (LAIVs). We examined serum antibodies (HAI assay, microneutralization assay, ELISA), local antibodies (ELISA) and virus-specific CD4+ and CD8+ central memory and effector memory T cells. Two doses vaccination of healthy volunteers with A (H5N2) and A (H7N3) LAIVs induced homological antibody and cellular immune responses (i. e. serum and local antibody conversions, virus-specific memory T cell growth). These vaccines also stimulated heterological immunity (heterological serum and local antibodies and T cells). Heterological immune response intensity depended on antigenic structure of vaccine strain and heterological virus, particularly on HA type.

Keywords

• avian influenza viruses
• immune response to influenza a viruses
• humoral immune response