Efficacy of Mycobacterium vaccae immunotherapy for patients with tuberculosis: A systematic review and meta-analysis

Tuberculosis (TB) is a significant cause of illness and death worldwide. Immunotherapy has been investigated in the treatment of TB. The purpose of this study was to perform a meta-analysis investigating the effectiveness of the M. vaccae vaccine. Medline, Cochrane, EMBASE, and Google Scholar were searched until November 5, 2015 using the keywords: tuberculosis, pulmonary TB, therapeutic vaccines, immunotherapy, M. vaccae, sputum smear. Randomized controlled trials (RCTs) or 2-arm prospective studies were included. The primary outcome was the sputum smear clearance rate at 1 or 2 months and 6 months after treatment. Secondary outcomes were improvement of chest X-ray findings, sputum culture negative rate at 1 or 2 months and 6 months, erythrocyte sedimentation rate (ESR), hemoglobin, and leukocyte count, weight gain, and mortality. Of 89 records identified, 13 RCTs were included in the meta-analysis. The number of patients ranged from 22 to 1337, and the mean age ranged from 26.4 to 44.3 y. Patients treated with M. vaccae were more likely to have negative sputum smear results at 1-2 months (pooled OR = 2.642, 95% CI: 1.623-4.301, P < .001) and at 6 months (pooled OR = 2.111, 95% CI: 1.141-3.908, P = .017), and have a negative sputum culture at 1 or 2 months (pooled OR = 2.660, 95% CI: 1.978-3.578, P < .001). The results of this meta-analysis suggest that M. vaccae immunotherapy may be effective in the treatment of pulmonary TB.