RESUMEN
Antigenic studies performed with vesicular stomatitis (VS) virus strains of the serotype Indiana (IND), Rancharia-Brazil/66 and Riberao-Brazil/78, isolated in the state of Sao Paulo, Brazil in 1966 and 1979, respectively, indicated that they have to be classified within the subtype IND-2 and that they are related to virus strains Salto-Argentina/63 and Cocal-Trinidad/61. The Espinoza-Brazil/77 strain isolated in 1977 in cattle of the state of Minas Gerais is closely related to the Alagoas-Brazil/64 strain, subtype IND-3. Studies of sera from recovered animals and immunodiffusion gel agar test confirmed the results obtained by 50 percent complement fixation tests. Field pathogenicity indicated that strains from the subtype IND-2 only affected horses, while the IND-3 subtype viruses affected cattle to a lower degree in comparison with horses. The northeast states and Minas Gerais, in Brazil, are affected by VS virus subtype IND-3, while in Sao Paulo and Rio Grande do Sul subtype IND-2 strains are identified