Gender inequity and age-appropriate immunization coverage in India from 1992 to 2006

Abstract

Background: A variety of studies have considered the affects of India's son preference on gender differences in child mortality, sex ratio at birth, and access to health services. Less research has focused on the affects of son preference on gender inequities in immunization coverage and how this may have varied with time, and across regions and with sibling compositions. We present a systematic examination of trends in immunization coverage in India, with a focus on inequities in coverage by gender, birth order, year of birth, and state.

Methods: We analyzed data from three consecutive rounds of the Indian National Family Health Survey undertaken between 1992 and 2006. All children below five years of age with complete immunization histories were included in the analysis. Age-appropriate immunization coverage was determined for the following antigens: bacille Calmette-Guérin (BCG), oral polio (OPV), diphtheria, pertussis (whooping cough) and tetanus (DPT), and measles.

Results: Immunization coverage in India has increased since the early 1990s, but complete, age-appropriate coverage is still under 50% nationally. Girls were found to have significantly lower immunization coverage (p<0.001) than boys for BCG, DPT, and measles across all three surveys. By contrast, improved coverage of OPV suggests a narrowing of the gender differences in recent years. Girls with a surviving older sister were less likely to be immunized compared to boys, and a large proportion of all children were found to be immunized considerably later than recommended.

Conclusions: Gender inequities in immunization coverage are prevalent in India. The low immunization coverage, the late immunization trends and the gender differences in coverage identified in our study suggest that risks of child mortality, especially for girls at higher birth orders, need to be addressed both socially and programmatically. ABSTRACT IN HINDI : See the full article online for a translation of this abstract in Hindi.

Figure 1

Girl-to-boy ratios of immunization coverage and combined estimates derived from previously published studies. The girl-to-boy immunization coverage ratios are based on the results of studies where data was available for calculation of pooled estimates. A CR of less than 1.0 indicates higher coverage in favour of boys.

Figure 2

Recommended expanded program of immunization (EPI) schedule for India. *OPV-0 is an additional dose of polio given at birth, but is not part of India's national immunization program. ✝Dashed lines indicate ages (1,2,3,5, and 9 months) used in determining appropriate immunization coverage within the child's first year. Children were considered to have age-appropriate EPI coverage if they had received all antigens recommended for their age.

Figure 3

Percent of children with age-appropriate coverage, by gender, antigen, and date of survey. Period of NFHS Surveys: 92-93 (NFHS 1), 98-99 (NFHS 2), and 05-06 (NFHS 3). Vertical bars represent 95% confidence intervals (CI).

Figure 4

Percent of children with age-appropriate coverage of EPI vaccines, by birth order, gender of previous birth(s), and survey period. Overall (EPI) age-appropriate immunization coverage for girls and boys at each birth order (column 1) and sibling gender composition of previous birth(s) (column 2) is represented by the bar chart for each year of the survey period (column 3). ✝Percentages in brackets (column 1) are the proportion of all births represented by each category of birth order and sibling gender in the 2005-6 survey. Horizontal bars represent 95% CI.

Figure 5

Trends in age-appropriate immunization coverage of EPI antigens in India by antigen, gender, and year of birth. Years of birth covered by NFHS surveys are indicated by solid points and lines. Dashed lines indicate periods where data is not available. Vertical bars represent 95% CI.

Figure 6

Percentage of children without age-appropriate immunization coverage in India at the time of each NFHS survey, by antigen and gender. We calculated the percentage of children born during each survey period who were not appropriately covered for each antigen according to their age. Vertical bars represent 95% CI.

Figure 7

Percentage of children with age-appropriate EPI coverage, girl-to-boy coverage ratio, and number of children without age-appropriate immunization coverage in India (2005-2006), by state and gender. NFHS 3 data and state-level sampling weights were used for this figure. ✝Absolute number of children without age-appropriate EPI coverage, estimated from the 2001 Indian Census [34]. *CR, coverage ratio, girls vs. boys **p ≦0.001.