[Results obtained using an attenuated bovine syncytial virus vaccine against bronchopneumonia of yearlings (author's transl)].

Bronchopneumonia of yearlings is a respiratory infection with bovine respiratory syncytial virus (BRS virus) occurring as a herd disease in young cattle. In severe cases, the clinical picture is identifiable; characteristic features are laboured respiration and a high morbidity rate. Following an acute onset, atypical interstitial pneumonia is observed on postmorten examination and bacteriological studies are negative. An attenuated live BRS virus vaccine was used against bronchopneumonia of yearlings in 1976, 1977 and 1978. This vaccine was inoculated in twenty-six herds supervised by the present author and numbering approximately 1,200 animals in the sensitive period of life. Moreover, the results obtained by sixty practitioners on vaccinating approximately 13,000 animals in 1978 were collected. Conclusive evidence of the effectiveness of the vaccine was not provided by these field trials. However, it is concluded from the findings that the satisfactory results obtained in the majority of cases were not accidental and that these results suggest that BRS virus vaccine is very likely to have a protective action against bronchopneumonia of yearlings.