Doctors have warned that a move by the federal government to include COVID-19 vaccine boosters in the standard definition of “fully vaccinated” would have enormous unintended consequences for guidance, restrictions, and mandates, as well as for private businesses.

“To suddenly say, up and down from federal to local, wait a minute, we’re now going to redefine things, that you need three doses to be fully vaccinated … it just becomes on the simple, practical side an enormous amount of work, which would lead to a lot of confusion,” said Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center.