Messages on COVID-19 prevention in India increased symptoms reporting and adherence to preventive behaviours among 25 million recipients with similar effects on non-recipient members of their communities

During health crises, like COVID-19, individuals are inundated with messages promoting health-preserving behavior. Does additional light-touch messaging by a credible individual change behavior? Do the features of the message matter? To answer this, we conducted a large-scale messaging campaign in West Bengal, India.