Washington (AFP)

A committee of US medical experts voted unanimously on Friday to recommend authorization of a second dose of Johnson & Johnson's Covid-19 vaccine.

The move could help ease feelings of uncertainty among some of the 15 million Americans who received a first dose but wondered if it would be enough to protect them, especially with the emergence of the Delta variant.

Members of the committee, brought together by the US Medicines Agency, the FDA, agreed that the evidence for safety and efficacy was in favor of injecting a second dose, as claimed by the pharmaceutical giant.

The recommendation may be changed later by the FDA, as well as the CDC, the principal federal health agency in the United States.

An emergency authorization could intervene in the days or weeks to come.

Several of these independent experts have suggested that if Johnson & Johnson applied for authorization of a booster dose, a second vaccine should actually be considered an "extra" dose, necessary to achieve a more complete vaccination.

"Frankly, I think it's always been a two-dose vaccine. It's complicated to recommend it as a single-dose vaccine," said Paul Offit, vaccine expert at the Pediatric Hospital in Philadelphia.

The "J&J" single-dose remedy has not been shown to be as effective as the two-dose messenger RNA vaccines.

But some data suggests that it is less likely to subside over time than vaccines from Pfizer and Moderna, due to its virus-vector technology.

Johnson & Johnson presented their study, conducted in the United States, showing that the efficacy of its vaccine against symptomatic forms of Covid was increased by 70 to 94% after the injection of a second dose, two months after the first, similar figures to those of messenger RNA vaccines.

Friday's recommendation follows that of the same committee voted on Thursday in favor of authorizing a booster dose of the Moderna vaccine for people at risk, especially those over 65 or those aged 18 to 64 whose work exposes them. more to contamination.

A similar decision had been taken several weeks earlier for Pfizer's vaccine.

The decision for the vaccine of "J & J" applies on the other hand to a greater number, since all those over 18 years who received a first dose of the vaccine at least two months ago are concerned.

© 2021 AFP