WASHINGTON — Earlier this month at a private event, Robert F. Kennedy Jr. and other top federal health officials announced a new National Institutes of Health center that would focus on patients with vaccine injuries, drawing fresh scientific firepower to an issue that’s long been central for the health secretary.

Yet days later, two leaders at the NIH said the center would also focus on long-term symptoms that people experience after an infection, a phenomenon most recently amplified among those experiencing long-term symptoms post-Covid. 

In fact, one senior NIH official, who asked not to be identified to speak freely, said that for people with long Covid symptoms, it can be hard to separate out whether those symptoms began because of a vaccine or an infection, as many people have experienced both. The immunological response mechanism is similar, they said, which means the treatment is similar.