Last year, Johns Hopkins physician Deborah Persaud made headlines all over the world when she announced that her team had effectively cured a newborn baby of HIV with an aggressive dose of post-birth antiretroviral drugs. The news was huge, and Persaud was named one of Time’s 10 most important people of 2013.

Sadly, the case that seemed like it might show a way forward in terms of HIV/AIDS treatment turned out more complicated; last Thursday, health officials announced that the baby still had traces of the disease.

Persaud and the other researchers were always very careful to say that the baby was “effectively cured,” perhaps out of fear that something like this would happen. Still, the news was “like a punch in the gut,” according to Mississippi physician Hannah B. Gay, who treated the child. Nonetheless, the fact that the virus disappeared for two years was “unprecedented,” Persaud said.