Spatial targeting and integration across vaccination, vitamin A and deworming programs throughout India 2019-21.

Background: Currently, most large-scale public health programs, such as immunization or anti-parasitic deworming, work in relative isolation. Integrating efforts across programs could potentially improve their efficiency, but identifying populations that could benefit from multiple programs has been an operational challenge.

Methods: We analyzed a nationally representative survey conducted in India between 2019 and 2021 to assess and map coverage of seven vaccines [Bacillus Calmette-Guérin (BCG), hepatitis B, polio, diphtheria-tetanus-pertussis (DTP), haemophilus influenza type b (Hib), rotavirus and measles-containing vaccine (MCV)], plus Vitamin A supplementation and anti-parasitic deworming treatment among 86 761 children aged 1-3 years old.

Results: National coverage varied widely by program, from 42% (rotavirus) to 95% (BCG). There was high correlation between district-level coverage estimates (r ≥ 0.7) and extensive spatial overlap in low-coverage populations. In simulated implementation strategies, we show that an integrated strategy that targets full immunization coverage for four core vaccines (BCG, polio, DTP, MCV) would achieve similar coverage to an optimal (but unrealistic) implementation strategy and far better coverage than multiple efforts focused on individual vaccines. Targeting the most under-vaccinated districts within states based on spatial clustering or coverage thresholds led to further improvements in full coverage per child targeted. Integration of anti-parasitic deworming or rotavirus vaccination into a core vaccine delivery mission could nearly double their coverage (from ∼45% to ∼85%).

Conclusions: Integrated delivery and geographic targeting across core vaccines could accelerate India's progress toward full immunization coverage. An integrated platform could greatly expand coverage of non-core vaccines and other child health interventions.