Factors influencing frontline health service providers' likelihood to recommend a future, preventive HIV vaccine to key populations in Karnataka, south India.

The HIV epidemic in the south Indian state of Karnataka disproportionately burdens key populations of men who have sex with men and female sex workers. Despite having successfully reduced HIV incidence among certain key populations through the use of targeted intervention, India's HIV epidemic remains one of its greatest public health issues. The best long-term strategy for managing the global HIV epidemic might involve a preventive vaccine; however, vaccine availability cannot guarantee its accessibility or acceptability. Vaccine recommendations from frontline health service providers have previously been identified as useful strategies to enhance vaccine uptake among target groups. This study used structured interviews to explore frontline health service providers' self-identified likelihood to recommend a future, preventive HIV vaccine to key populations in Karnataka. A modified social ecological model was then used to categorise factors that might prevent health service providers from recommending an HIV vaccine. Overall, 83% of health service providers reported that they would be very likely to recommend an HIV vaccine to men who have sex with men and female sex workers, while less than one-third of participants identified one or more barrier to vaccine recommendation. Intrapersonal, interpersonal, and structural/political factors were most commonly reported to act as potential barriers to future HIV vaccine recommendation among health service providers in Karnataka. This study adds to the limited body of literature focussing on future HIV vaccine acceptability in low- and middle-income countries and highlights some of the several complexities surrounding vaccine acceptability and uptake among key populations in Karnataka.