Associations between family planning, healthcare access, and female education and vaccination among under-immunized children

Background: Increasing childhood vaccination, family planning, healthcare access, and women's empowerment are targets of the Sustainable Development Goals (SDG). Barriers to healthcare access impede vaccination; tackling goals holistically could create larger gains than siloed efforts. We studied Nepal, Senegal, and Zambia to test the association between childhood vaccinations and other SDG indicators to identify clustered deprivations. We quantified how under-immunized children with few - or no - vaccines and their mothers were vulnerable in SDG areas. Methods: We analyzed Demographic and Health Surveys from Nepal, Senegal, and Zambia. Through ordinal logistic regressions, controlling for household/mother's characteristics, we identified strong predictors of the number of vaccine doses one-year-old children received. Through bootstrapping and optimal propensity scores matching, we compared children with no or few vaccine doses (0-2 doses in early 2000s, or 0-4 in late 2010s) to children who received eight doses (DTP1-3, MVC1, Pol1-3, and BCG vaccines). Findings: Mothers of children who received eight doses were 14-30 % more likely than mothers of children with few or no doses to have accessed a health facility in the last year (95 % CIs were 16-44 % in Nepal 2001, - 5 % to 33 % Nepal 2016, 3-26 % Senegal 2005, 1-31 % Senegal 2019, 9-38 % Zambia 2001-02, 7-36 % Zambia 2018), knew on average 0.7-1.5 more contraceptive methods (0.9-2.0 Nepal 2005, 0.1-1.5 Nepal 2016, 0.6-1.7 Senegal 2005, 0.2-1.7 Senegal 2019, 0.1-1.4 Zambia 2001-02, 0.5-1.4 Zambia 2018), and had 10-22 % higher literacy rates (12-32 % Nepal 2001, - 7 % to 36 % Nepal 2016, 10-26 % Senegal 2005, -3 to 22 % Senegal 2019, - 4 % to 28 % Zambia 2001-02, 5-36 % Zambia 2018). Interpretation: Children with few or no vaccine doses and their mothers were behind in access to family planning, healthcare, and education compared to fully vaccinated children and their mothers. Such differences can further impede immunizations; integrated education and health services are needed to improve vaccination outcomes.