A new study suggests HIV can remain inactive inside a small amount of cells or a single cell only to re-emerge later and wreak havoc, HealthDay reports.

According to the article, researchers followed 20 HIV-positive patients who had gone off their antiretroviral (ARV) medications for two weeks at a time as a part of the study. Researchers examined how the virus evolved over time and found that the disease could resurface from a small amount of cells or even a single cell when medication is stopped.

But there is good news. Huldrych Gunthard, MD, the study’s co-author and researcher at the University Hospital Zurich in Switzerland, said that the virus isn’t replicating itself or evolving into new forms while dormant. This could mean that HIV-positive patients who adhere to the drug regimens as prescribed won’t have to fight a newly strengthened virus.

“It is a very good message for patients and doctors,” Dr. Gunthard said.