The U.S. Food and Drug Administration has greenlit updated Covid-19 boosters designed specifically to target the omicron BA.4 and BA.5 variants of the coronavirus.
Moderna Inc. (Nasdaq: MRNA) and Pfizer Inc. (NYSE: PFE) have both been engineering such shots since late June, when the FDA asked them to develop vaccines with BA.4 and BA.5 — the subvariants of the virus' omicron variant, which have been responsible for around 400 deaths each day in the U.S. this summer — in mind.
The shots contain…