• Pfizer and BioNTech said they have submitted early stage clinical trial data to the FDA as part of their U.S. application seeking authorization of a Covid-19 vaccine booster shot.
• In a phase one trial, a booster dose generated "significantly higher neutralizing antibodies" against the original coronavirus strain as well as the beta and delta variants, the companies said.
• Federal health officials aren't recommending booster doses for the general public at this time.

Pfizer and BioNTech said Monday they have submitted early stage clinical trial data to the Food and Drug Administration as part of their U.S. application seeking authorization of a Covid vaccine booster for everyone 16 and older — not just people with weak immune systems.

In a phase one trial, a booster dose of the vaccine generated "significantly higher neutralizing antibodies" against the original coronavirus strain as well as the beta and delta variants, the companies said in a press release. Participants in the trial received a third shot of the two-dose vaccine about eight to nine months after receiving their second shot, they said.

"The data we've seen to date suggest a third dose of our vaccine elicits antibody levels that significantly exceed those seen after the two-dose primary schedule," Pfizer CEO Albert Bourla said in a statement. "We are pleased to submit these data to the FDA as we continue working together to address the evolving challenges of this pandemic."

The companies said late-stage trial results evaluating the third dose are expected shortly and will also be submitted to the FDA and other regulatory authorities worldwide.

The announcement from the drugmakers comes after federal health officials Friday approved administering Covid booster shots of Pfizer's and Moderna's vaccines to Americans with weakened immune systems, which includes cancer and HIV patients and people who have had organ transplants.

U.S. new data suggests immune-compromised individuals don't produce an adequate immune response after receiving two doses of a Covid vaccine.

Pfizer's latest data looks at the booster's safety and immune response in people with otherwise healthy immune systems.

Federal health officials aren't recommending booster doses for the general public at this time, but White House chief medical advisor Dr. Anthony Fauci has said everyone will "likely" need a booster shot at some point .

Covid vaccine makers, including Pfizer and Moderna, have repeatedly contended that everyone will eventually need a booster shot and potentially extra doses every year, just like for the seasonal flu.

Pfizer has cited data out of Israel, where country officials said last month the two-dose vaccine was just 39% effective against getting the disease, blaming the drop in performance on the highly contagious delta variant. When Pfizer submitted its original application to the FDA in December, it said its shots were about 95% effective in preventing Covid infections.

The vaccine is still considered highly effective against severe disease, hospitalizations and deaths, according to Israeli health officials.