Tweaked COVID Vaccines in Testing Aim to Fend Off Variants

April 13, 2021

(Medscape) – Dozens of Americans are rolling up their sleeves for a third dose of COVID-19 vaccine — this time, shots tweaked to guard against a worrisome mutated version of the virus. Make no mistake: The vaccines currently being rolled out across the U.S. offer strong protection. But new studies of experimental updates to the Moderna and Pfizer vaccines mark a critical first step toward an alternative if the virus eventually outsmarts today’s shots.