Roybal Fellow Sparks Winning Nudge to Increase Vaccine Uptake

The COVID-19 pandemic has demonstrated both the need for lifesaving vaccines and the challenge of getting many people to take them. A recent megastudy suggests that text messaging can boost vaccination usage—depending on which words are used. To find the optimal message, researchers held a nationwide contest that focused on reminders about flu vaccines.

Jehan Sparks, a postdoctoral fellow at the USC Schaeffer Roybal Center for Behavioral Interventions in Aging, helped devise the winning script. As part of a team including a UCLA and a University of Toronto professor, she designed a nudge consisting of two text reminders. The first text was sent 72 hours before a patient’s primary care appointment, with the second being sent 24 hours in advance.

The texts, which let people know that a flu shot was “waiting” or “reserved for you” increased vaccination rates by 11%. This straightforward messaging from Sparks and her colleagues also proved to be more effective than attempts at humor or interactive engagement.

The Behavior Change for Good Initiative at the University of Pennsylvania conducted the randomized megastudy in coordination with Walmart and two major regional health systems. The 19 texting nudges were tested in more than 47,000 patients. Meanwhile, a control group received physician appointment reminders with no mentions of flu shots.

Interventions such as the one proposed by Sparks and her teammates are urgently needed. A Pew Research Center poll found that only 60% of American were willing to get vaccinated against COVID-19. Even some who express willingness may not follow through. Yet widespread vaccine uptake is crucial to building herd immunity from any viral infection—from the flu to the novel coronavirus.

“I am hopeful that the ‘reserved for you’ language in our nudges can save lives,” Sparks says of the low-cost intervention. As a postdoctoral research fellow at the USC Schaeffer Center and UCLA Anderson School of Management, she explores how people get locked into certain ways of thinking, as well as how they can free themselves from negative patterns to make healthier choices.

“This simple yet effective nudge is just one reason why we’re so happy that Jehan has joined us,” says Jason Doctor, co-principal investigator of the Roybal Center and director of health informatics at the Schaeffer Center. Doctor’s own nudges, including those aimed at reducing overprescribing, have been adopted across the U.S. and in England. “It is our hope that the Roybal Center will encourage and foster this kind of creative, simple intervention that will lead to improved health outcomes.”

Funded by the National Institute on Aging, the USC Roybal Center for Behavioral Interventions in Aging strengthens the ability of clinicians to recommend safe and effective treatments for elderly patients through evidence-based behavioral interventions—or nudges. The center’s research helps advance healthy aging for older adults who are economically insecure, culturally diverse and historically underserved.