Vaccination coverage and the factors influencing routine childhood vaccination uptake among communities experiencing disadvantage in Vellore, southern India: a mixed-methods study

BACKGROUND: In 2015, the Vellore district in southern India was selected for intensified routine immunization, targeting children from communities experiencing disadvantage such as migrant, tribal, and other hard-to-reach groups. This mixed-methods study was conducted to assess routine immunization coverage and the factors influencing childhood vaccination uptake among these communities in Vellore. METHODS: We conducted a cross-sectional household survey (n = 100) and six focus group discussions (n = 43) among parents of children aged 12–23 months from the known communities experiencing disadvantage in Vellore during 2017 and 2018. Multivariate logistic regression was conducted to examine associations between the parental characteristics and children’s vaccination status in the household survey data; the qualitative discussions were analyzed by using the (previously published) “5As” taxonomy for the determinants of vaccine uptake. RESULTS: In the household survey, the proportions of fully vaccinated children were 65% (95% CI: 53–76%) and 77% (95% CI: 58–88%) based on information from vaccination cards or parental recall and vaccination cards alone, respectively. Children whose mothers were wage earners [Adjusted prevalence odds ratio (aPOR): 0.21, 95% CI = 0.07–0.64], or salaried/small business owners [aPOR: 0.18, 95% CI = 0.04–0.73] were less likely to be fully vaccinated than children who had homemakers mothers. In the focus group discussions, parents identified difficulties in accessing routine immunization when travelling for work and showed knowledge gaps regarding the benefits and risks of vaccination, and fears surrounding certain vaccines due to negative news reports and common side-effects following childhood vaccination. CONCLUSIONS: Vaccination coverage among children from the surveyed communities in Vellore was suboptimal. Our findings suggest the need to target children from Narikuravar families and conduct periodic community-based health education campaigns to improve parental awareness about and trust in childhood vaccines among the communities experiencing disadvantage in Vellore. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-11881-8.