Abstract: Objective To evaluate the effect and safety of Mycobacterium vaccae vaccine (M.vaccae vaccine) to treatment outcome of new pulmonary tuberculosis cases.Methods 168 new bacteriological positive pulmonary tuberculosis cases were divided into immunotherapy (A,84 cases)group and control (B,84 cases) group randomly.The cases in two groups were treated by the same chemotherapy regimen of 2HRZE/4HR.The group A were treated immunotherapy with M.vaccae vaccine for 2 months.There was no immonotherapy with M.vac cae in group B.Results The sputum smear negative conversion rates in group A 1,2 and 6 months after treatment were 36.9%, 79.8% and 97.6% respec tively;those in group B were 19.0%,53.8% and 96.4% respectively.The sputum culture-negative conversion rates in group A the end of 1,2 and 6 months treatment were 47.6%,85.7% and 98.8% respectively;those in group B were 17.9% ,67.9% and 97.6% respectively.The sputum negative conversion rates of group A were signi ficantly higher than those of group B after 1 and 2 months treatment(P＜0.01 ).But there were no statistically significant differences between the two groups at the end of 6 months after treatment (P＞0.05).Compared with group B,the effect on improving of X ray manifestation in group A were better (P＜0.01).The side effects of M.vaccae vaccine were rare and slight.The bacterio logical relapse rates in group A,B were 1.3%,2.6% respectively(P＞0.05). Conclusion M.vaccae vaccine is helpful on speeding negative conversion,improving of X ray monifestation for new bacteriological positive pul monary tuberculosis.

Key words: Tuberculosis,pulmonary, Mycobacterium vaccae, I mmunotherapy