In case there was any doubt, a new study out today confirms that HIV acts quickly. The idea that it lies dormant is now fully debunked.

“It was stunning to see how quickly the immune system was affected,” said Haynes, who is the lead author on the study.

To deal with the shrinking window, clinicians can check for the presence of HIV more often, but the potential for catching cases early enough for intervention looks bleak. The earliest and most infectious stage of HIV has vague and practically unnoticable symptoms.

“It looks like HIV does a lot of damage very early on,” Haynes said. “Now we feel that the opportunity to intervene most effectively may range from about five to seven days after infection.”

Doctors are going to have to start screening patients for the HIV virus even if they come in with what seems like a headache or a common cold, Leone said.

Why they say 5 to 7 days when the window for effective PEP has been 72 hours for a while now, I don’t know…

The upside is that good HIV tests should be able to detect infection much more quickly. Which means you don’t have to wait 3 months to be sure you’re neg. It also means that if your doctor does a blood draw and tells you to come back in two weeks – by then it’s too late to do anything about it. That may be fine for routine checks, but it’s not OK when you think you just got infected.