CDC Limits Review of Vaccinated but Infected; Draws Concern (1)

Federal health officials this month decided to limit how they monitor vaccinated people who have been infected with Covid-19, drawing concern from some scientists who say that may mean missing needed data showing why and how it happens.

At the end of April, more than 9,000 Americans were reported to be infected after being vaccinated, according to the U.S. Centers for Disease Control and Prevention. While that’s a tiny percentage of the 95 million people fully inoculated at the time, researchers still want to find out what specific mechanisms may be spurring the infections.

Rare breakthrough cases are expected ...