Keywords
Avian influenza; H5N2; Low pathogenicity strains; Inactivated vaccine; Excretion; qRT-PCR
Abstract
In Mexico, the strategy used for controlling the Avian Influenza Virus (AIV) involves the use of immunizations through an inactivated emulsion vaccine (H5N2), which protects birds from the disease. It has been shown that the strain used in this vaccine is phylogenetically distant from the strains that are isolated in the field. Therefore, the goal of this study was to prepare and evaluate a polyvalent vaccine with genetically divergent isolates of the low-pathogenicity H5N2 avian influenza virus strains that are prevalent in Mexico. A polyvalent vaccine (Poly-AI) was prepared using five isolates that exhibited phylogenetic divergence from the low-pathogenicity avian influenza H5N2 virus strains found in Mexico. Chickens were immunized with Poly-AI and challenged 28 days post-vaccination with two Low Pathogenic Avian Influenza Virus (LPAIV) isolates contained in the vaccine and one High Pathogenic Influenza Virus (HPAIV). Serology was done at different times and clinical signs were recorded. This is the first study that documents the degree of pathogenicity differences between various isolates that exhibit genetic variation in the nation. The experimental Poly-AI vaccine eliminated the clinical signs of the disease, demonstrated 100% protection against the challenge with a highly pathogenic strain and decreased excretion when challenged with homologous and high virulence strains, which was detected by qRT-PCR.
Citation
Bojórquez EA, Anaya ER, Espinosa GG, Vargas FD and Loza-Rubio E. Evaluation of a Polyvalen Vaccine Obtained From Divergent Low Pathogenic H5N2 Isolates of the Avian Influenza Virus in Mexico. SM Vaccine Vaccin.2015;1(2):1010.