Pfizer is about to take authorization from the US FDA for the third dose of its Covid-19 vaccine, saying Thursday that one more shot in the coming 12 months can boost immunity and maybe help to defeat the latest coronavirus mutant. Research from multiple countries shows the Pfizer vaccine and other generally used Covid-19 vaccines offer strong protection against the highly infectious delta variant, which is spreading fastly in the world.

Two doses of most vaccines are important to develop fighting antibodies against all variants of the coronavirus, not just the delta variant and most of the world still is desperate to get those initial emergency doses as the pandemic continues to increase rapidly. But antibodies generally decrease over time, so studies also are undertaken to understand if and when a booster shot should be given.

On Thursday, Pfizer’s Dr. Mikael Dolsten told The Associated Press that early data from the company’s vaccine study says that a person’s antibody levels jump five to ten levels up after a third dose, in comparison to their second dose. In August, Pfizer is planning to get the Food and Drug Administration (FDA) for emergency authorization of a third dose, he said.