U.S. health officials confirmed Wednesday that Americans vaccinated by Pfizer and Moderna will be able to receive a third booster injection eight months after the second dose on Sept. 20.

In a statement, senior officials, including Rochelle Wallinski, director of the Centers for Disease Control and Prevention (CDC) and acting FDA Janet Woodcock, said, “Available data clearly show that protection against SARS-CoV-2 infection is beginning to decline after the first two. Together, we began to see evidence of diminished protection against mild and moderate diseases.

They concluded that “a booster dose is needed to increase and prolong the protection provided by the vaccine.”

“We are ready to give the booster dose to all Americans from September 20. Eight months have passed since the second dose,” said Anthony Fossi, a White House adviser on epidemiology.

The first users of this booster dose were the “groups of retirees in nursing homes”, “other seniors” and “many health workers” who were the first groups to be vaccinated in the United States.

Health officials point out that the booster dose is “essential” for people who have been vaccinated with the single-dose Johnson & Johnson vaccine.

But the vaccination campaign with this vaccine has not started in the United States “until March 2021” and data on it are expected “in the coming weeks”, knowing that Johnson & Johnson vaccinated people are a minority in the United States.