Pfizer CEO Albert Bourla (right) said a fourth booster shot is "necessary" due to "waning effectiveness" of the third shot.
Mr. Bourla, a licensed veterinarian, said a 4th dose is needed during an appearance on NBC's "Meet the Press" on Sunday.
"Right now, the way that we have seen, it is necessary, a fourth booster right now," Bourla said.
"The protection that you are getting from the third, it is good enough, actually quite good for hospitalizations and deaths. It's not that good against infections, but doesn't last very long. But we are just submitting those data to the FDA and then we will see what the experts also will say outside Pfizer."
By coincidence, triple vaccinated former President Barack Obama announced his breakthrough COVID case on Twitter the same day.
I just tested positive for COVID. I've had a scratchy throat for a couple days, but am feeling fine otherwise. Michelle and I are grateful to be vaccinated and boosted, and she has tested negative.
It's a reminder to get vaccinated if you haven’t already, even as cases go down.
— Barack Obama (@BarackObama) March 13, 2022
Pfizer is reportedly testing a vaccine that would work against COVID variants that haven't been discovered yet.
Pfizer hopes to submit data to the FDA on a vaccine for children under 5 years old by next month, which could make the shots available for infants and toddlers as early as May.
Pfizer reported revenue of $37 billion from sales of its mRNA vaccines in 2021. The pharma corporation expects revenues of $92 billion in 2022.