In December, Michael Mina of Harvard’s T.H. Chan School of Public Health and I called for a trial, to assess the viability of dose-sparing strategies like delaying second shots, to make vaccines available to more people earlier. Britain, Canada and other countries delayed second shots during the Alpha surge, though there was no trial, so it was harder to pursue such strategies globally even as so many people lost their lives.

To assess the need and effectiveness of boosters, especially for the elderly, a trial could have begun in May or June, when the protective effect of early vaccinations might have begun to wane. By now, we’d have real data rather than a news release from the U.S. Health and Human Services Department announcing that boosters will be available to all vaccinated Americans as early as September, while at the same time saying that is subject to evaluation by the Food and Drug Administration and the Centers for Disease Control and Prevention. If there’s data proving the need for boosters, where is it? If not, why did federal officials issue the news release?

All of this is not to say that boosters are useless, or that we should always wait for perfect data before acting, particularly in offering boosters to high-risk groups like the immunocompromised or the elderly. However, announcing that a third Moderna or Pfizer dose will be offered soon even to young, healthy Americans when millions around the world have yet to receive a single dose, requires more than a news release. And ordinary people should not be reduced to trying to decipher such issues by following debates between individual scientists online.