EN
Live vaccines prepared from M. intracellulare serotype 5 and 16, BCG and killed vaccine from M. avium, were used for the vaccination against tuberculosis in 2191 chickens, 6-10 weeks old, in a small husbandry. The birds were observed for 15 months after vaccination. None of the vaccines used gave satisfactory protection of the hens against infection with M. avium. The most immunogenic activity was displayed by the vaccine prepared from M. intracellulare serotype 5. The birds immunized with the vaccine were affected with tuberculosis half as often as the control hens.