Socioeconomic inequalities and vaccination coverage: results of an immunisation coverage survey in 27 Brazilian capitals, 2007-2008

Abstract

Background: Since 1988, Brazil's Unified Health System has sought to provide universal and equal access to immunisations. Inequalities in immunisation may be examined by contrasting vaccination coverage among children in the highest versus the lowest socioeconomic strata. The authors examined coverage with routine infant immunisations from a survey of Brazilian children according to socioeconomic stratum of residence census tract.

Methods: The authors conducted a household cluster survey in census tracts systematically selected from five socioeconomic strata, according to average household income and head of household education, in 26 Brazilian capitals and the federal district. The authors calculated coverage with recommended vaccinations among children until 18 months of age, according to socioeconomic quintile of residence census tract, and examined factors associated with incomplete vaccination.

Results: Among 17,295 children with immunisation cards, 14,538 (82.6%) had received all recommended vaccinations by 18 months of age. Among children residing in census tracts in the highest socioeconomic stratum, 77.2% were completely immunised by 18 months of age versus 81.2%-86.2% of children residing in the four census tract quintiles with lower socioeconomic indicators (p<0.01). Census tracts in the highest socioeconomic quintile had significantly lower coverage for bacille Calmette-Guérin, oral polio and hepatitis B vaccines than those with lower socioeconomic indicators. In multivariable analysis, higher birth order and residing in the highest socioeconomic quintile were associated with incomplete vaccination. After adjusting for interaction between socioeconomic strata of residence census tract and household wealth index, only birth order remained significant.

Conclusions: Evidence from Brazilian capitals shows success in achieving high immunisation coverage among poorer children. Strategies are needed to reach children in wealthier areas.

Figure 1

Study design for immunisation coverage survey in Brazilian capital cities.

Figure 2

Per cent of children surveyed who by 18 months of age had received childhood immunisations included in the national immunisation programme, according to socioeconomic quintile of residence census tract (A=wealthiest, E=poorest) in 27 Brazilian capitals. BCG, bacille Calmette-Guérin; DTP, diphtheria–tetanus–whole cell pertussis; HepB, hepatitis B; Hib, Haemophilus influenzae type b; MMR, measles–mumps–rubella; OPV, oral polio vaccine.

Figure 3

Per cent of children completely vaccinated by 18 months of age by socioeconomic stratum of residence census tract and household wealth index for all 27 Brazilian capital cities, 2007–2008.

Figure 4

Per cent of children who by 18 months of age had received vaccines not included in the national immunisation programme, by socioeconomic quintile of residence census tract (A=wealthiest, E=poorest) in 27 Brazilian capitals. Note: Vaccines not included in the national immunisation calendar were purchased from private immunisation clinics or provided at public referral centres for children with specific medical indications.