 Study Design: IMPI is a randomized double-blind placebo-controlled 2x2 factorial pilot trial that will enroll 1400 patients from multiple centres in Kenya, Malawi, Mozambique, Nigeria, Sierra Leone, South Africa, Uganda and Zimbabwe. Patients with tuberculous pericarditis who fulfill the inclusion criteria will be randomly assigned to receive oral prednisolone or placebo for 6 weeks and Mycobacterium w injection or placebo for 6 months. Patients will be followed closely during the intervention period at weeks 2, 4, 6, and months 3 and 6. Six-monthly follow-up will be performed thereafter for up to two years. The recruitment of the 1400 patients will be performed over 54 months, with a minimum follow-up period of 6 months for the last participants recruited in the trial. The Population Health Research Institute at McMaster University will manage and coordinate the study in association with the IMPI Project Office that is located in the Department of Medicine, Groote Schuur Hospital, Cape Town, South Africa. 