Effectiveness of a community-level social mobilization intervention in achieving the outcomes of polio vaccination campaigns during the post-polio-endemic period: Evidence from CORE Group polio project in Uttar Pradesh, India

Background: A social mobilization (SM) initiative contributed to India’s success in polio elimination. This was the CORE Group Polio Project (CGPP) India, a partner of the Uttar Pradesh (UP) SM Network and which continued its SM activities, even during the polio-free period through a network of multi-level social mobilizers. This paper assesses the effects of this community-level SM (CLSM) intervention on the extent of community engagement and performance of polio Supplementary Immunization Activity campaigns (SIAs) during the post-polio-endemic period (i.e., from March 2012 to September 2017). Methods: This study followed a quasi-experimental design. We used secondary, cluster-level data from CGPP India’s Management Information System, including 52 SIAs held from January 2008 to September 2017, covering 56 blocks from 12 districts of UP. We computed various indicators and performed Generalized Estimating Equations based analysis to assess the statistical significance of differences between the outcomes of intervention and non-intervention areas. We then estimated the effects of the SM intervention using Interrupted time-series, Difference-in-Differences and Synthetic Control Methods. Finally, we estimated the population influenced by the intervention. Results: The performance of polio SIAs changed over time, with the intervention areas having better outcomes than non-intervention areas. The absence of CLSM intervention during the post-polio-endemic period would have negatively impacted the outcomes of polio SIAs. The percentage of children vaccinated at polio SIA booths, percentage of ‘X’ houses (i.e., households with unvaccinated children or households with out-of-home/out-of-village children or locked households) converted to ‘P’ (i.e., households with all vaccinated children or households without children eligible for vaccination), and percentage of resistant houses converted to polio acceptors would have gone down by 14.1 (Range: 12.7 to 15.5), 6.3 (Range: 5.2 to 7.3) and 7.4 percentage points, respectively. Community engagement would have reduced by 7.2 (Range: 6.6 to 7.7) percentage points. Conclusions: The absence of CLSM intervention would have significantly decreased the level of community engagement and negatively impacted the performance of polio SIAs of the post-polio-endemic period. The study provides evidence of an added value of deploying additional human resource dedicated to social mobilization to achieve desired vaccination outcomes in hard-to-reach or programmatically challenging areas.