Scientists have discovered the first virus capable of falling ill by being infected with another virus. This exciting twist has reignited the debate over whether viruses could be considered living things.

“The fact that it can get sick makes it more alive,” said virologist Jean-Michel Claverie of the Mediterranean Institute of Microbiology in Marseilles, France, where the virus was analyzed after being found in a cooling tower in Paris.

The scientists named the attacking virus Sputnik, and are calling it a virophage because it acts similarly to a bacteriophage—a virus that infects bacteria.

Sputnik’s victim is “one of a family of physically immense viruses, the first of which was isolated from a British cooling tower” in 2003 and dubbed a mimivirus. The size of this latest mimivirus is unprecedented, prompting researchers to name it a mamavirus.

According to virologist Eugene Koonin, a co-author of the findings of the study, the relationship between Sputnik and the mamavirus is a unique “host-parasite” pairing. “It’s the first time that these viruses have actually exchanged genes,” he said.

And Sputnik had a profound impact on the mamavirus. “The team found that cells co-infected with Sputnik produce fewer and often deformed mamavirus particles, making the virus less infective,” according to Nature News.

Presently, scientists and researchers are unsure of the significance of viral parasites, and whether the organisms could have an impact on the environment or human health. But according to Wired, “At the very least, it expands our idea of what is possible in the viral world.”