Comprehensive Immunisation Among Children Aged 12-23 Months in India-A Multilevel Modelling Analysis From the National Family Health Survey (2015-21).

Under-5 child mortality due to vaccine preventable diseases (VPDs) contributes to an estimated burden of ∼5.2 million deaths globally, mostly within low- and middle-income countries (LMICs). Despite ongoing efforts to expand immunisation coverage, gaps in immunisation remain a persistent public health concern, underscoring the need to examine recent trends and determinants of full immunisation in India. The objective of this study is to estimate vaccination coverage and identify factors associated with full immunisation among children aged 12-23 months from 2015 to 2021. We utilised the National Family Health Survey-4 (NFHS-4) and NFHS-5 datasets to determine the vaccination status (fully vaccinated/not fully vaccinated) among children aged 12-23 months using multilevel logistic regression analysis. The full vaccination coverage increased from 62.54% [95% CI: 61.81, 63.26] in 2015-16 (NFHS-4) to 76.81% [95% CI: 76.18, 77.42] in 2019-21 (NFHS-5). The factors associated with significantly higher odds of full vaccination in both NFHS-4 and NFHS-5 included higher maternal age and education, higher wealth quintile, having ≥4 antenatal care visits, institutional delivery, pregnancy registration and exposure to media. The lower odds of full immunisation were associated with having more than one child and being Muslim in both NFHS-4 and NFHS-5. The elimination of rural residence as a significant factor for lower child vaccination odds in NFHS-5, a contrast to NFHS-4, suggests that national health policies have become more effective at reducing geographical disparities and therefore more equitable. With increasing saturation of vaccination coverage, the government programme needs a specific focus on addressing key determinants associated with vaccine uptake to achieve complete vaccination.