Why COVID boosters weren’t tweaked to better match variants

More COVID-19 booster shots may be on the way -- but when it’s your turn, you’ll get an extra dose of the original vaccine, not one updated to better match the extra-contagious delta variant. And that has some experts wondering if the booster campaign is a bit of a missed opportunity to target delta and its likely descendants. “Don’t we want to match the new strains that are most likely to circulate as closely as possible?” Dr. Cody Meissner of Tufts Medical Center, an adviser to the Food and Drug Administration, challenged Pfizer scientists recently.