This thing you’re looking at? It’s the virus that causes AIDS.

In a hushed auditorium at an obscure conference in Utah 16 years ago, French scientist Jean-Claude Chermann struggled to convey in English the discovery of his career: that the  lymphadenopathy-associated virus, or LAV, was the organism wreaking havoc on human immune systems around the globe. Until this moment, the symptoms were alarmingly visible while the cause remained shrouded in mystery.

A year earlier, the French team had reported in Science about isolating LAV from the blood of people with AIDS. Now Chermann was filling in the picture. From Utah he traveled to the Centers for Disease Control in Atlanta to provide LAV specimens for comparison with two years of PWA blood samples. By month’s end, CDC tests showed LAV present in every case. Soon the virus was rechristened the human immunodeficiency virus, or HIV, and the word retrovirus found a home in all our vocabularies.

No U.S. newspaper covered Chermann’s announcement, and the media waited until April to broadcast that the cause of AIDS had been found. Almost overnight, the breakthrough was eclipsed by the feud between U.S. and French scientists over who “owned” it. Still, as Randy Shilts wrote in And the Band Played On, the researchers gathered that day in 1984 grew breathless in anticipation of the coming fight. The code had been broken; the monster had a face. “Now,” one conference attendee recalls thinking, “we can start working.”