Three US medical certifying boards have warned doctors that they risk losing their certification and licence if they spread covid vaccine misinformation. Internists, family doctors, and paediatricians received an email on 9 September that quoted a warning from the Federation of State Medical Boards in July1 which read: “Providing misinformation about the covid-19 vaccine contradicts physicians’ ethical and professional responsibilities, and therefore may subject a physician to disciplinary actions, including suspension or revocation of their medical licence.”2 Richard Baron, president and chief executive of the American Board of Internal Medicine (ABIM), told The BMJ that the move was an attempt to establish a standard of care. “As standard setting organisations, we thought it was important to be on record, in a public way, to make clear that putting out flagrant misinformation is unethical and dangerous during a pandemic.” Baron said that the statement has been well received—“4 to 1 positive.” But community physicians contacted by The BMJ thought differently. “When I got that email I thought I’d better not put anything on social media about vaccines,” said Shveta Raju, a community physician in the Atlanta, Georgia, area, who has treated covid patients and led the vaccination effort at her outpatient clinic. “The email was sent more as a veiled threat to keep doctors on the official, established narrative, and that’s what I find chilling,” …