2.7.1 Pathogenicity in chickens
According to the recommendations of the World Organization for Animal Health (OIE, 2018), ten 6-week-old SPF chickens per group were intravenously inoculated with 100 μl tenfold diluted virus-containing allantoic fluids. All the birds were observed for 10 days to determine the intravenous pathogenicity index (IVPI).