Physicians at Harvard Medical College weigh in on what does not—and what might—encourage people to get a coronavirus vaccine. In a New York Times opinion letter, they write, “providing more, frightening information intended to change their beliefs is ineffective for many or may even cause further entrenchment against vaccination.” In other words, data, or a logical argument, doesn’t work.

They consider a recent study about the Human Papillomavirus Vaccination (HPV). Surprisingly, women who had cervical cancer were no more likely to get their children vaccinated, and women who had a cancer “scare” were only slightly more likely than those who didn’t have cancer to get their children vaccinated.

From this study, the authors conclude that knowing someone who had COVID-19 or hearing stories about people who had the disease won’t convince people to get vaccinated. Although the doctors refer to this as “more information,” I would consider this an emotional appeal, depending on how “stories” are described.

Regardless, the authors suggest relying on methods that seem to work: negative incentives. Offering lottery tickets and other types of payments hasn’t influenced large numbers of people. Only threats—for example, if you don’t get vaccinated, you can’t come to work (a type of incentive) may be the best approach for now.

In his book Think Again, Adam Grant has other ideas, but they require more time and personal relationships—asking questions and giving people a choice.