A Mega-Study of Text-Message Nudges Encouraging Patients to Get Vaccinated at their Pharmacy

We partnered with Walmart to test 22 nudges designed to boost vaccination rates in their pharmacies. Nudges were delivered via text message to over 700,000 Walmart pharmacy patients in the fall of 2020 and encouraged patients to visit Walmart for a flu vaccine. We demonstrate that the best behaviorally informed messages can increase pharmacy vaccination rates by up to 8.3% compared to the least effective messages over a roughly one month follow-up period. The most effective messages in our field experiment matched the tone of typical pharmacy communications and reminded patients that a flu shot was waiting for them. These insights suggest that carefully crafted messages informed by the results of this study could nudge the adoption of other vaccines for other infectious diseases, including COVID-19.