The paper’s authors, which include top officials at the World Health Organization and Food and Drug Administration, have consistently opposed lifting public health restrictions in the face of new variants, guidance that seems to contradict their argument about the mildness of breakthrough cases.

The vaccinated “need to continue to wear masks,” the World Health Organization’s chief scientist, Soumya Swaminathan, tweeted in August, adding that the Delta variant “demands that.” The FDA officials who resigned over the Biden administration’s plan to offer booster shots later this month, Philip Krause and Marion Gruber, likewise touted masks and social distancing in July as a way to “control viral variants.” Of the 18 scientists who criticized boosters, more than half are on record as supporting burdensome interventions since the summer surge.

The Washington Free Beacon asked those scientists why, if boosters aren’t necessary, masks and social distancing are. They did not respond to a request for comment.