Please cite this article in press as: Gonzalez, D.D., et al., Evaluation of a bovine rotavirus VP6 vaccine efficacy in the calf model of infection and disease. Vet. Immunol. Immunopathol. (2010), doi:10.1016/j.vetimm.2010.04.015 ARTICLE IN PRESS G Model VETIMM-8288; No. of Pages 6 Veterinary Immunology and Immunopathology xxx (2010) xxx–xxx Contents lists available at ScienceDirect Veterinary Immunology and Immunopathology journal homepage: www.elsevier.com/locate/vetimm Short communication 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 Vanesa Rodriguez, Fernando María Fernandez, Andrés Wigdorovitz, Viviana Gladys Parre ˜ no, María José Dus Santos ∗ Instituto de Virología, CICVyA, INTA, Las Caba˜ nas y de los Reseros s/n, Castelar, 1686 Hurlingham, Buenos Aires, Argentina article info Article history: Received 16 December 2009 Received in revised form 15 April 2010 Accepted 23 April 2010 Keywords: Bovine rotavirus Recombinant VP6 Passive immunity abstract 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 6 h 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 in both 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. © 2010 Published by Elsevier B.V. 1. Introduction Group A bovine rotavirus (BRV) is a major cause of neonatal diarrhea in calves worldwide. Considering the early susceptibility of calves to BRV infection, the presence of local passive Abs (IgG1 and IgA) in the gut lumen derived by unabsorbed colostrum and milk plays an important role in protection against BRV infection and disease (Fernandez et al., 1998; Parreno et al., 2004; Saif et al., 1983, 1987). In addition, high titers of passive circulating Abs posse a com- plementary role in protection against BRV diarrhea due to ∗ Corresponding author. Tel.: +54 11 4621 1676; fax: +54 11 4621 1743. E-mail address: mdussantos@cnia.inta.gov.ar (M.J. Dus Santos). transfer of serum IgG1 into the intestine of neonatal calves (Besser et al., 1988a, 1988b; Saif et al., 1983, 1987). The intermediate layer of the virus is formed by protein VP6, which constitutes approximately 51% of the virion by weight. This protein is highly immunogenic but does not induce neutralizing Abs. Since Abs against VP6 are highly cross reactive among group A rotaviruses, VP6 immuniza- tion could potentially provide heterotypic protection (Tang et al., 1997). Vaccine development studies have shown a high level of protection when VP6 was used as an immunogen in exper- imental models (Chen et al., 1998; Choi et al., 1999, 2000, 2002; Dong et al., 2005; Yu and Langridge, 2003). Virus-like particles (VLPs) containing only the inner capsid protein VP2 and the intermediate capsid protein VP6 have also 0165-2427/$ – see front matter © 2010 Published by Elsevier B.V. doi:10.1016/j.vetimm.2010.04.015