The success of smallpox eradication in the mid-1970s drew attention to the immunization programme in India. The Expanded Programme on Immunization (EPI), developed for immunizing children during the first year of life was launched in 1978 mainly in the urban areas. Through the subsequent years, more vaccines were included in the programme, e.g. OPV in 1979 and the vaccine to immunize pregnant mothers with tetanus toxoid (TT) vaccine in 1983.