Pfizer and BioNTech plan to file for emergency use authorization for COVID vaccine booster as Delta variant spreads

Pfizer announced on Thursday that its COVID vaccine booster shot could further protect individuals from "all currently known variants" of COVID-19 — including the highly transmittable Delta variant. The booster shot is currently undergoing trials, the company said, and has shown "encouraging clinical trial data in a small number of participants in our study."

Pfizer said that the initial two doses that patients received have elicited "strong immune responses" against the Delta variant and that current studies are focused on whether the booster shot will increase that response even further. Trial data has shown that when given six months after the second dose, Pfizer's booster has a "consistent tolerability profile" and neutralizes an immune response. Pfizer and BioNTech plan to share their booster data with the Food and Drug Administration in August and file for emergency use authorization shortly thereafter, a Pfizer spokesperson said.