WASHINGTON—U.S. government scientists are pushing back against calls for one-dose regimens for two Covid-19 vaccines designed to be administered with two shots, saying there isn’t enough evidence that a single dose provides long-term protection.
“It is essential that these vaccines be used as authorized by FDA in order to prevent Covid-19 and related hospitalizations and death,” Peter Marks, director of the Food and Drug Administration’s center that oversees vaccines, told The Wall Street Journal.
The FDA late last year approved a two-dose regimen for vaccines from Moderna Inc. and from a partnership of Pfizer Inc. and BioNTech SE. More recently it approved use of a one-dose regimen for a vaccine from Johnson & Johnson .
Some scientists and lawmakers have called for shifting to a one-dose regimen for all the vaccines, citing preliminary studies showing one shot can be effective. They contend shifting to one shot will allow the U.S. to accelerate the pace of vaccinations.
In a March 2 letter to acting Health and Human Services Secretary Norris Cochran, seven physician members of Congress urged the department “to consider issuing a revised emergency use authorization as soon as possible” that might lead to single-dose use of the Pfizer and Moderna vaccines.