Factors affecting timeliness in vaccination of under-five children in India: A cross-sectional study using the NFHS 5 survey during COVID-19.

Immunization is an essential intervention that protects millions of children against vaccine-preventable diseases across the world. Although vaccination coverage has improved over the years, ensuring timely administration continues to be a major challenge affecting child health in India. The COVID-19 pandemic further aggravated this situation. A cross-sectional study using the Kids Recode dataset of the National Family Health Survey 5 was conducted, which inlcuded 232920 children under 5 y of age. Timeliness was considered as 4 d earlier and up to 28 d after the standard date in comparison with the National Immunization Schedule. Regression analysis was used on Survey Data to assess the impact of factors related to children, mothers, households, communities, and the COVID-19 pandemic on timeliness by deriving adjusted Prevalence Ratios. Timeliness at birth was highest (94.6%), however, it declined for subsequent doses at 6 weeks (74.2%), and 14 weeks (67.5%). Untimeliness at 14 weeks was mainly due to Polio 3 (60.2%) and Rotavirus 3 (58.0%) vaccines. Factors associated with untimeliness included - low birth weight, fewer antenatal visits, non-institutional delivery, no maternal education, rural residency and belonging to lower socioeconomic strata. Children residing in the Central and Northeast zones had the highest prevalence of untimeliness in receiving vaccines. Despite the COVID-19 pandemic disruptions, the timeliness of vaccination was comparable between the pre- and post-pandemic periods. This study shows that the untimeliness of vaccination is influenced by factors related to the child, mother, household and community. Comprehensive interventions involving various stakeholders are required to improve the timeliness of vaccination.