Indian Journal of Virology

Bluetongue is an arthropod (Culicoides)-borne OIE list “A” viral disease of sheep and other ruminants. There are 24 serotypes of Bluetongue virus (BTV) prevalent in susceptible animals globally. The disease is endemic in India and 21 serotypes of BTV have been reported to circulate in animals. It causes huge economic losses, which are due to: 1) poor quality of meat, fleece and hide, 2) teratogenicity and abortion and 3) ban on export of animals and their products to BT free countries. There is no vaccine available in the country hence a binary ethylenimine (BEI) inactivated saponified BTV-1 vaccine was prepared and its efficacy was evaluated in seronegative adult sheep. Safety and sterility of the vaccine was assured by standard procedures. The BEI degraded the genome RNA of the virus, making the vaccine usable without the risk of mutation or recombination of genome in nature. Seronegative sheep were vaccinated, boostered and challenged thereafter. Vaccine produced slight to moderate local inflammatory response (take) at the site of inoculation. Good humoral immune response was observed in all the vaccinated animals. Both group specific and type specific neutralizing antibodies were observed to develop in vaccinated animals as detected in AGPT, cELISA (per cent inhibition values ranging from 83–100) and VN test (neutralizing antibody titre of 1:512 in all the vaccinated animals). Post challenge viremia was also detected for shorter period in comparison to the controls. Vaccine is considered to be safe and highly immunogenic and can be used for disease control after slight refinement.