Comparative studies have been carried out to compare the effec­tiveness of the local combined inactivated respiratory virus vaccine in­corporating IBR, PI-3 and BVD viruses (pneumo-3) and the imported modified live with killed BVD virus (cattle Master 4) vaccines. Five to six months old calves were randomly assigned to 3 groups with 6 animals/ group. Calves in group I were inoculated on days 0 and 14 with 5m1 of local combined inactivated respiratory virus vaccine (pneumo-3), and the second group was inoculated on days 0 and 14 with 2m1 of modified live virus vaccine with killed BVD vaccine (cattle master 4). The remain­ing 6 calves were maintained as unvaccinated controls. Immune respons­es were measured by means of ELISA, serum neutralization assay against the same fractions of the vaccine and haemagglutination inhibi­tion test against PI-3 virus. Both vaccines, either prepared locally or im­ported gave, full protection against challenge with each disease causing strain with that fraction. All vaccines induced production of antibodies. However, the ratio of neutralizing antibody titre change in IBR, PI-3 and BVD viruses-specific lgG antibody level was lower for calves that re­ceived inactivated virus vaccines than for calves that received the modi­fied live virus vaccine. Results suggested that the commercially inacti­vated vaccine stimulated production of protective antibodies without replication of virus in the tissues of the host leading to decrease the production of neutralizing antibodies in immunized calves.