1. Laboratory of Immunology and Virology, Department of Veterinary Pathology, Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP, 14884-900, Brazil
2. Current affiliation: Embrapa Pecuária Sudeste, Rodovia Washington Luiz km 234 s/n, São Carlos, SP, 13560-970, Brazil