Evaluation of different strains of Newcastle disease virus in inactive vaccines in the challenge with Genotype VII vNDV

Newcastle disease virus (NDV) causes economic losses to the poultry industry. ND vaccines are used in different forms and include one of the strains. The purposes of this study were comparing titer and protection created by killed vaccines with different NDV seeds against genotype VII, comparing the autogenous genotype VII vaccine with conventional vaccines, comparing the effect of adjuvants in making the autogenous vaccine, and examining vaccination of live Newcastle vaccine on titer and protection created with inactivated ND vaccines against Genotype VII vaccines. The study was conducted in seven groups of day-old chicks. In addition to the control group, all groups injected subcutaneous vaccines containing V4, Ulster 2C, Lasota, G7 genotype with Adjuvant A or B, and Lasota with a live Lasota vaccine at 14 days old. At old-day, the chickens received the B1 vaccine. Serum was given before the challenge, at the age of 35 days and 14 days after challenge. At 35 days old, chickens were challenged by the ocular-nasal method with the genotype VII virus and the mortality was assessed up to 7 days after the challenge. The results of titration rate in 3 weeks after injection showed the Ulster 2C strain vaccine had a higher titer (1.26 ±7) than other groups (insignificant difference P>0.05). In Lasota vaccine group, Genotype VII with Adjutant A and control group, the mortality rate was 13.3, 10, and 40 percent, respectively. The results showed that different commercial vaccines in terms of titers do not have significant difference (titer and survival).