Evaluation of combined inactivated vaccines against avian influenza subtypes [H5N1, H9N2] and avian infectious Bronchitis in chicken using montanide and paraffin oil adjuvants

Abstract

The goal of the presented work was to prepare and evaluate physical characters and immunogenicity of a combined inactivated Avian Influenza Virus (AIV) H5N1, H9N2 subtypes and Infectious Bronchitis Virus (IBV), strain D-88 oil emulsion vaccines. The prepared vaccines were sterile and safe. Also, they were ensured to be water in oil (W/O) emulsions using drop test, conductivity (zero mS/cm). Particle size were 950 nm and 1050 nm and dynamic viscosities were 19.52 Mpa.s and 39.65 Mpa.s for the vaccine with Montanide™ ISA 71 RVG adjuvant and the vaccine with paraffin oil adjuvant, respectively. They showed stability for 24 months at 4 °C with no separation. Combined inactivated oil emulsion vaccines induced cellular and humoral immune responses in vaccinated chicks. The vaccine with Montanide™ ISA 71-RVG adjuvant provided 100% protection percent for AIV H5N1 without shedding of AIV H9N2 and IBV in comparison to the combined vaccine with paraffin oil adjuvant that gave 84% protection percent for AIV H5N1 and shedding of AIV H9N2 and IBV occurred 6 th day post challenge. Montanide™ 71-RVG adjuvant has the flexible ratio of oil and antigenic media in the vaccine (60:40) allowed using large amount of virus that showed good impact on its immunogenicity, over the paraffin oil adjuvant which has restricted ratio of oil and antigenic media of the vaccine (73:27).