Pfizer to seek OK for 3rd vaccine dose

Pfizer is about to seek US authorization for a third dose of its Coronavirus disease 2019 (Covid-19) vaccine, saying Thursday that another shot within 12 months could dramatically boost immunity and maybe help ward off the latest worrisome coronavirus mutant.

Research from multiple countries shows the Pfizer shot and other widely used Covid-19 vaccines offer strong protection against the highly contagious delta variant, which is spreading rapidly around the world and now accounts for most new US infections.