Polio vaccine hesitancy in the networks and neighborhoods of Malegaon, India.

OBJECTIVES Eradication and control of childhood diseases through immunization can only work if parents allow their children to be vaccinated. To learn about social network factors associated with polio vaccine hesitancy, we investigated social and spatial clustering of households by their vaccine acceptance status in Malegaon, India, an area known for vaccine refusal and repeated detection of polio cases. METHODS We interviewed family heads from 2462 households in 25 neighborhoods in July 2012 and constructed social networks based on advice seeking from other households. We restricted our main analyses to surveyed households for which we also had data on whether they accepted the polio vaccine for their eligible children or not. RESULTS Data from 2452 households was retained and these households made 2012 nominations to 830 households. Vaccine-refusing households had fewer outgoing ties than vaccine-accepting households. After excluding 24 isolated households, vaccine-refusing households had 189% more nominations to other vaccine-refusing households (93% more in the largest component of the network) compared to vaccine-accepting households, revealing that vaccine-refusing households cluster in the social network. Since roughly half of all ties connect households within neighborhoods, vaccine-refusing clusters lie in spatially localized "pockets". CONCLUSIONS The social (and spatial) clustering of vaccine-refusing households could be leveraged to tailor communication strategies to improve vaccine acceptance and community perceptions of immunization programs for polio and other vaccine-preventable diseases.