Percentage of Children getting complete immunization (X₇): The complete immunization of children helps in reducing child mortality. Hence the higher value of complete immunization is a good indication of child health. Many studies have shown that full immunization coverage reduces child mortality. The universal immunization programme (UIP) was introduced in 1985-86 with the objective to cover at least 85 per cent of all infants against the vaccine preventable disease by 1990. The target now is to achieve 100 per cent immunization coverage. Pulse Polio immunization launched in December 1995 to eliminate the polio was one such effort. According to RCH survey, in India 53.3 percent of the children received immunization. Bihar recorded the lowest immunization coverage, 17 per cent of the children in the state got complete immunization. In Madhya Pradesh, Uttar Pradesh, and Rajasthan the immunization coverage was 47.3, 41.7, and 29.8 per cent respectively. Andhra Pradesh, Goa, Himachal Pradesh, Kerala, Maharastra, Punjab, Tamil Nadu and all the UTs (excluding Chandigarh) recorded more than 70 percent immunization coverage. Madurai district in Tamil Nadu recorded the highest coverage of immunization (99.5 per cent). Contrary to this, Tuensang district in Nagaland recorded the lowest immunization coverage (1.6 per cent). 

The upper limit of the complete immunization is fixed at 99.5 and the lower limit at 1.6. The index is computed as 

Index₇ = 100*(X₇ – 1.6)/(99.5-1.6) 

            = 100*(X₇ – 1.6)/97.9 

Where X₇ is the percent of children getting complete immunization in a particular district. 

Higher the percentage of immunization in district, higher the index value and better the ranking of district.