Pfizer to seek OK for 3rd vaccine dose; shots still protect

Pfizer says it is about to seek U.S. authorization for a third dose of its COVID-19 vaccine.

The company said Thursday that another shot could dramatically boost immunity and maybe help ward off the latest worrisome coronavirus mutant.

Research from multiple countries shows the widely used COVID-19 vaccines offer strong protection against the highly contagious delta variant.

Two doses of most vaccines are critical to develop high levels of virus-fighting antibodies. But those antibodies naturally wane. So studies also are underway to tell if and when boosters might be needed.

Pfizer says early data from a company trial suggests people’s antibody levels jump after they get a third dose.