Development and Evaluation of an Inactivated Influenza A(H5N8) Vaccine

Highly pathogenic avian influenza viruses are circulating in lots of species, causing major outbreaks both wild and domestic poultry. Since its first emergence 2014, clade 2.3.4.4 H5N8 widely spread the world resulting enormous economic losses. In Egypt, newly emerging high (HPAI) have been detected poultry birds since 2016/2017 winter season. AI is cocirculating with LP H9N2 HP H5N1 Egyptian environment. Poultry vaccination strategy Egypt based on commercially available H5 vaccines as an essential control policy, while majority commercial utilized not effective against viruses. The present study included 3 experimental inactivated 2 antigenic proteins currently strain A/chicken/Egypt/Q16684C/2019 (H5N8), internal segments A/PR/8/1934 (H1N1) virus. Then, protective efficacy three forms (HAH5N8+7PR8, NAH5N8+7PR8 HA, NAH5N8+6PR8) were compared regarding parental PR8 virus vaccinated specific pathogen free chickens. NAH5N8+6PR8 well HAH5N8+7PR8 HA showed highest protection capacity challenged SPF chickens able to elicit titers virus-neutralizing antibodies. Thus, a continuous active surveillance needed determine most dominant updating vaccine seed strains.