France considers just 1 dose for some
PARIS — France is weighing whether to give people who have recovered from COVID-19 only one vaccine dose instead of two, a practice that if enacted and followed by other countries could free up tens of millions of doses.
“It’s likely that we’ll see similar moves elsewhere, given that we’re facing a shortage of vaccine doses,” said Tobias Kurth, the director of the Institute of Public Health at Berlin’s Charité hospital.
France’s health advisory body has recommended that one shot provides sufficient protection, acting like a booster shot, for previously infected people.
“People who have already been infected retain an immunological memory,” the advisory body said in a release justifying its changed guidance.
The nonbinding guidance still needs to be approved by the French government, which usually follows the body’s recommendations, though it has been hesitant to deviate from standard practices in its coronavirus vaccination campaign.
In a statement last week, vaccine maker Pfizer cautioned that “we do not have any data regarding this approach and our study was designed to dose all participants regardless of previous infection.”
But Florian Krammer, a professor of vaccinology at the Icahn School of Medicine at Mount Sinai in New York, said the one-dose recommendation in France was in line with results from recent research.
A study by Krammer and his colleagues, not yet peer-reviewed, found that previously infected people have an equal or even better antibody response after one dose than individuals who received two shots and had not had COVID.
“We found that people who had COVID before mounted a very, very strong and a very quick response after the first shot,” he said.
The Mount Sinai paper’s conclusions were based on limited data from 109 people, of whom over a third used to be infected with the coronavirus.
Separate work published this month by researchers from the University of Maryland, New York University and a group of Israeli researchers has come to similar conclusions.
All the coronavirus vaccines currently approved by U.S. and European Union regulators require two doses, though Johnson & Johnson has a single-shot candidate awaiting regulatory assessment.
The U.S. and E.U. have so far reported a total of about 50 million coronavirus cases, meaning that as many doses could be freed up if the French guidance were applied across the board.
“That’s enough to vaccinate 25 million people, which is more than the population of some smaller countries,” Krammer said.
In its guidance, France’s health advisory body said anyone with the coronavirus should wait at least three months and ideally “closer to 6 months” after the infection to get vaccinated.
The recommendation to wait several months appeared intended to maximize the share of the population with at least some degree of protection, and it was made under the assumption that a prior infection provides a degree of immunity for up to six months, though the exact length remains uncertain.