With a dangerous disease circulating in the population, government’s goal should be to reduce the amount of harm people do to each other. Vaccination can reduce such harms, but making Covid-19 vaccination mandatory would do more harm than good.

The United States can achieve “herd immunity” without resorting to mandates. There has already been a substantial uptick of trust in the vaccines. A recent poll by the Kaiser Family Foundation found the share of American adults willing to be vaccinated rose from 63 percent in September to 71 percent in December. That’s close to the 75 to 85 percent that Dr. Anthony Fauci, the government’s top infectious disease expert, estimates we would need to achieve herd immunity. That increase was the result of persuasion—greater public awareness of the dangers of Covid-19 and more evidence about the vaccines’ safety and efficacy—not mandates.

That same poll suggests most of the holdouts are also open to persuasion. Of the 27 percent who say they are not currently willing to be vaccinated, only 37 percent say they don’t trust vaccines in general. The most prevalent concerns among the unwilling relate to side effects and a desire to collect more data. That means that the best way to achieve herd immunity in the U.S. is to treat vaccine skeptics like adults, give them truthful information, and let them decide.

In today’s politically charged environment, a mandate could ironically make skeptics less willing to be vaccinated—or to comply with other pandemic-control measures. More than half of the vaccine holdouts already say they don’t trust the government. A mandate would make them even less trusting. It would also fuel the broader movement against vaccines by allowing activists to argue that the government knows it can’t win the vaccine debate with persuasion alone. Ultimately, a vaccine mandate could inadvertently delay population immunity and increase the death toll from Covid-19.