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Online Journal of Veterinary Research

(Including Medical and Laboratory Research)

Established 1994

ISSN 1328-925X

Volume 26 (2):137-147, 2022.

Herd immunity in buffaloes by intranasal live gdhA P. multocida B:2 vaccine


Rafidah O1,2, Zamri-Saad M1, Nasip E2, Saharee AA1


1Faculty of Veterinary Medicine, Universiti Putra Malaysia, and 2Department of Veterinary Services and Animal Industry, Kota Kinabalu, Sabah, Malaysia.




Rafidah O, Zamri-Saad M, Nasip E, Saharee AA., Herd immunity in buffaloes by intranasal live gdhA P. multocida B:2 vaccine, Onl J Vet Res., 26 (2):137-147, 2022. We report herd immunity to haemorrhagic septicaemia (HS) in large herds of buffalo given intranasal live attenuated gdhA P. multocida B:2. Three groups of 30 - 50 buffaloes from endemic location with HS outbreak reported 2 months earlier and from non-endemic locations were grazed without vaccination. Then 30% in each group were inoculated 5ml 106 CFU/mL live attenuated gdhA P. multocida B:2 intranasally. After vaccination, buffaloes commingled with other animals and a booster was given 10 months after. Serum was taken from 30% buffaloes of each group prior to and every 2 month for 22 months to determine herd immune status by ELISA. The endemic or non-endemic herd status was compared 15 non-vaccinated controls. We found (p<0.05) higher herd antibody levels in both endemic and non-endemic areas before vaccination. However, afte, antibodies in both areas gradually increase and peaking (p<0.05) at 6 months then gradually falling to 10 months. Following booster dose at month 10, the herd antibody levels decreased drastically to an insignificant (p>0.05) level as the unvaccinated group at 12-14 months before significantly (p<0.05) recovered thereafter until the end of 22-month study period. It was concluded that field vaccination using gdhA derivative P. multocida B:2 increased the herd immunity that lasted between 8 and 10 months before a booster dose was required.


Key words: gdhA derivative Pasteurella multocida B:2; immune response; field buffalo.