Evaluation of a Bovine Rotavirus VP6 vaccine efficacy in the calf model of infection and disease

DIEGO DANIEL GONZALEZ; MARINA VALERIA MOZGOVOJ; DEMIAN BELLIDO; DANIELA RODRIGUEZ; FERNANDO MARIA FERNANDEZ; ANDRES WIGDOROVITZ; VIVIANA PARREÑO; MARIA JOSE DUS SANTOS

VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY

ELSEVIER SCIENCE BV

Año: 2010 vol. 137 p. 155 - 160

0165-2427

Group A Bovine Rotavirus (BRV) is the major cause of acute viral gastroenteritis in neonatal calves worldwide. Due to the early susceptibility to the infection prevention strategies are based on the improvement of passive immunity levels through cow vaccination in the last third of gestation. The major capsid antigen (VP6) of BRV is the most immunogenic viral protein and it is highly conserved among group A BRV. In this work, VP6 protein from BRV C-486 strain (P[1]G6) was expressed in insect cells using the baculovirus expression vector system. Recombinant VP6 was used to immunize cows and vaccine´s efficacy was assessed in a colostrum-deprived calf model of BRV infection and disease. Immune colostrum pool was generated using first and second milking of the immunized cows. Calves receiving one dose of immune colostrum within the first six hour of life, or colostrum deprived calves were orally inoculated with virulent BRV at 2 days of age. The animals were monitored for diarrhea, virus shedding and isotype-specific antibodies responses to BRV both in feces and serum. Calves receiving VP6-immune colostrum showed a reduction of both diarrhea and virus shedding (in terms of viral titer and excretion period) in comparison with the colostrum-deprived calves.