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“Nudges” Successfully Encourage COVID Vaccine Holdouts to Get the Jab


New UCLA-led research suggests simple texts boosted vaccination numbers

New UCLA-led research suggests that simple text messages emphasizing the easy availability of the COVID-19 vaccines successfully boosted the number of people who got the vaccination.

The findings from researchers at the David Geffen School of Medicine at UCLA, UCLA Anderson School of Management and Carnegie Mellon University suggest that unobtrusive behavioral nudges such as this can help increase vaccine uptake. The researchers found that this held true across all demographics, including groups that have been hesitant to receive the vaccine.

Text messages that emphasize the easy availability of the vaccine are effective, the research showed.

Hengchen Dai, Assistant Professor of Management and Organizations and Behavioral Decision Making

The addition of ownership language produced a boost in appointment and vaccination rates, compared to text messages without such language, said lead co-author Hengchen Dai, assistant professor of management and organizations and behavioral decision making at UCLA Anderson. But adding an informational video did not yield a detectable effect on the patients’ behavior, which may be because few clicked on the video link to view it, she said.

“It is very interesting that while a video-based intervention seems to elevate vaccination intentions in a hypothetical setting where people are asked to watch the video, this intervention does not yield benefits in a real setting where people are invited to watch the video and where we assess actual behavior,” Dai said. “Clearly, more work needs to be done to understand how to effectively change vaccine hesitancy.”

The paper will be published August 2, 2021, in the peer-reviewed journal Nature. “We found that text messages stressing the accessibility of the vaccine, and that included ownership language — such as that the vaccine has just been made available to you and to claim your dose today — significantly increased vaccine uptake,” said Dr. Daniel Croymans, medical director of quality and a primary care physician at UCLA Health and the study’s corresponding author. Croymans led the patient outreach effort.

The researchers analyzed data from two randomized controlled trials with UCLA Health patients, most of them over age 65, who were eligible for the COVID-19 vaccine in January and February 2021. In the first trial, about 93,000 participants who had initially been notified of their eligibility for the vaccine received one of four types of text messages or no text reminders. Those reminders consisted of a simple text; a reminder with an informational video; a text with ownership language such as “The vaccine has just been made available for you” or “Claim your dose”; or a text message with both the ownership language and informational video. All reminders included a direct link to a page allowing patients to schedule a vaccination appointment within the health system, which was intended to reduce the barriers for patients to take action.

They found that appointment rates within six days of getting the reminders were nearly double among those receiving texts compared to those who did not receive a text during the same period (13.2% versus 7.2%). Vaccination rates remained higher one month after text reminders (17.56% versus 13.89%). This approach was particularly effective with people who regularly schedule a seasonal flu shot, and the benefits even held when the researchers examined vaccinations obtained outside the health system studied.

In the second trial, more than 67,000 people who did not schedule an appointment after receiving the first reminder were divided into two groups. Eight days after that first text reminder, one group was sent a second reminder text, and the other group was not.

The researchers found that the group who received the second reminder were 1.65% likelier than the other group to schedule an appointment for their first dose within six days of receiving the text. They were also 1.06% likelier to follow through and actually get the shot. Although it is a small change, the researchers note that people from this group were initially reluctant to get the vaccine at all.

The text reminders are both effective and inexpensive tools to motivate people across all demographics to get the vaccine, which is particularly important with the highly contagious Delta variant making its way across the globe, said co-lead author Silvia Saccardo, assistant professor in the Department of Social and Decision Sciences at Carnegie Mellon University.

“One simple reminder, which is cost effective, could prompt people to schedule their appointment,” Saccardo said. “Getting scheduled for the first dose was the biggest barrier. Once scheduled, people went to the appointment and then returned for their second dose.”

The text nudges may be applicable to other health-related behaviors, Croymans said.

“We could use them to encourage patients to get screened for colorectal cancer, or to connect them to health educators to improve outcomes in chronic conditions, such as diabetes,” he said. “It’s a potential tool that could help physicians help their patients avoid serious illness or complications that could have been prevented.”

Other study co-authors are Dr. Maria Han, Lily Roh, Dr. Naveen Raja, Sitaram Vangala, Hardikkumar Modi, Shital Pandya and Michael Sloyan of UCLA.