New COVID-19 boosters that target today's most common omicron strains are set to begin soon after the Centers for Disease Control and Prevention endorsed the updated shots Thursday.
The decision by CDC Director Rochelle Walensky came shortly after the agency's advisers said if enough people roll up their sleeves, the shots could blunt a winter surge.
The CDC's advisers struggled with who should get the new booster and when because only a similarly tweaked vaccine, not the exact recipe, has been studied in people so far. Comparing the tweak that has been studied in people and the one the U.S. actually will use, "it is the same scaffolding, part of the same roof, we're just putting in some dormers and windows," said Dr. Sarah Long of Drexel University.
But those vaccines were designed to target the virus strain that circulated in early 2020. Effectiveness drops as new mutants emerge and more time passes since someone's last shot. Since April, hospitalization rates in people over age 65 have jumped, the CDC said. But "I just feel that this was a bit premature" given the absence of human data on how well it works, he said.