Many agree that the original course of vaccination offered significant protection against serious illness in children. Data from the C.D.C. shows that two or more doses of Covid vaccines were 40 percent effective at preventing emergency room visits and hospitalizations among children under the age of 5.

The first report from the Trump administration’s Make America Healthy Again Commission, released last week, appears to be rife with errors, including some studies that don’t exist.

Abrupt switch left Minnesota doctors concerned about impact on vaccine hesitancy, insurers uncertain about future vaccine coverage policies.