Tweaked COVID vaccines in testing aim to fend off variants

Cole Smith receives a Moderna variant vaccine shot from clinical research nurse Tigisty Girmay at Emory University's Hope Clinic, on Wednesday afternoon, March 31, 2021, in Decatur, Ga. Smith, who received Moderna's original vaccine a year ago in a first-stage study, said returning wasn't a tough decision. "The earlier one, it was a great success and, you know, millions of people are getting vaccinated now. ... If we're helping people with the old one, why not volunteer and help people with the new one?" (AP Photo/Ben Gray)

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.

"We need to be ahead of the virus," said Dr. Nadine Rouphael of Emory University, who is helping to lead a study of Moderna's tweaked candidate. "We know what it's like when we're behind."

It's not clear if or when protection would wane enough to require an update but, "realistically we want to turn COVID into a sniffle," she added.

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