Vol. 8, Issue 11 (2019)

Author(s):
Raya Sarkar, Chanchal Guha, Ujjwal Biswas and Partha Sarathi Jana

Abstract:
The present study was conducted to know the HI titres in pigeons challenged with velogenic strain of PPMV -1 (local strain). Twenty four healthy pigeons were vaccinated with live attenuated lentogenic strain PPMV-1 vaccine (local isolate) and 12 non-vaccinated healthy pigeons were randomly selected and taken to the Laboratory Animal House in isolated condition, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata for the challenge study. Vaccinated pigeons were divided into two groups i.e. vaccinated challenge group and vaccinated control group, comprised of 12 pigeons in each group. All the pigeons were inoculated orally by velogenic strain PPMV-1 @ 10⁶ EID₅₀ to each bird. Serum samples were collected from all the birds of all the 3 groups weekly for 3 weeks for the estimation of HI titres. HI log mean titre in the non-vaccinated challenge group was below detectible level (0.00 ± 0.00) before challenge. After challenge, the mean titre non-significantly increased (i.e. 0.301 ± 0.00) in the survived birds (4 numbers) at the end of 1^st week of post challenge whereas, in the vaccinated control group, the log HI mean antibody titre before immunization was 1.982 ± 0.044 which was also above protective level. With the advancement of time, there was non-significant alteration of log HI mean antibody titres i.e. 2.007 ± 0.085, 1.957 ± 0.094 and 2.007 ± 0.1393 on the day of 7^th, 14^th and 21^st respectively which were always persisted above protective level. In the vaccinated challenge group the log HI mean titre values before vaccination was 2.258 ± 0.045 which was above protective level (i.e. 1.50 ± 0.00). After challenge, the mean HI log titre significantly (≤0.05) decreased to 2.025 ± 0.091 and 2.025 ± 0.082 at the end of 1^st week and 2^nd week of post challenge respectively but never became below protective level. Thus, the live attenuated lentogenic strain PPMV-1 vaccine (local isolate) was potent and efficacious, gave adequate protective antibody response and withstood challenge with the velogenic strain of PPMV-1.