The Food and Drug Administration last week authorized Americans 50 and over to get a fourth Covid vaccine dose. Some of the FDA's own experts disagree with the decision, but the agency simply ignored them. Eric Rubin, editor in chief of the New England Journal of Medicine, sits on the advisory committee. He told CNN last month that he hadn't seen enough data to determine whether anyone needs a fourth dose whose immune system isn't seriously deficient. At the crux of the broad opposition to second boosters is the recognition of B- and T-cells, which public-health officials have long ignored. They talk only about antibody levels, which tend to decline in the months after vaccination. B- and T-cells, activated by the primary vaccine series or an infection ... are highly and durably effective at preventing serious illness from Covid. An additional vaccine dose induces a fleeting high in antibody levels, offering only mild and short-lived protection. Two top FDA officials quit the agency in September complaining of undue pressure to authorize boosters. Marion Gruber, former director of the Office of Vaccine Research and Review, and her deputy, Philip Krause, later wrote about the lack of data to support a broad booster authorization. Hours after the FDA authorized the fourth dose, the Centers for Disease Control and Prevention gave its formal approval to the move"also without convening its external vaccine experts.