HIV was discovered by French scientists Françoise Barré-Sinoussi and Luc Montagnier at the Institut Pasteur in Paris, who published their findings in the journal Science on May 20, 1983. American researcher Robert Gallo at the National Cancer Institute published confirming work a year later. The discovery sparked one of the most consequential scientific disputes of the 20th century, involving competing claims, a patent fight that reached the level of heads of state, and a Nobel Prize that left one key player out.
The First Clues: Five Cases in Los Angeles
Before anyone knew the virus existed, doctors noticed something strange. On June 5, 1981, the CDC published a brief report in its weekly bulletin describing five young, previously healthy men in Los Angeles who had developed a rare lung infection called Pneumocystis carinii pneumonia. All five were active homosexuals, and the infection they shared was one typically seen only in people with severely weakened immune systems. That short bulletin, covering cases treated between October 1980 and May 1981 at three different hospitals, became the first published report of what would later be called AIDS.
More clusters of unusual infections and rare cancers followed in cities across the United States. By the end of 1981, the syndrome had a loose clinical profile but no known cause. Researchers suspected a virus, and the race to find it began on both sides of the Atlantic.
The French Team Isolates the Virus
At the Institut Pasteur, Luc Montagnier led a small team that included Françoise Barré-Sinoussi, an experienced retrovirologist with deep expertise in growing and detecting viruses in the lab. In early 1983, the group obtained a lymph node biopsy from a patient with swollen glands, an early symptom of what would become AIDS. They placed the cells in culture and began looking for signs of a retrovirus.
The approach Barré-Sinoussi chose turned out to be critical. The only known human retrovirus at the time was HTLV-1, a virus that makes cells multiply indefinitely. Rather than assume the new virus behaved the same way and wait weeks for cell growth, the team checked their cultures every two to three days for reverse transcriptase, a signature enzyme produced by retroviruses. Within about two weeks, they found it. And the timing mattered enormously: the very next day, the infected cells were dead. As Barré-Sinoussi later explained, if they had waited even a few more days, the virus would have destroyed its host cells and vanished from the culture entirely.
To keep the virus alive, the team quickly added fresh lymphocytes from a blood bank sample, rescuing the culture just in time. They named the new pathogen Lymphadenopathy-Associated Virus, or LAV, and published their results in Science on May 20, 1983.
The American Claim and the Dispute
Robert Gallo, a prominent virologist at the National Cancer Institute in Bethesda, Maryland, had been working on the same problem. Gallo’s lab had previously discovered HTLV-1 and was well positioned to hunt for a retroviral cause of AIDS. On May 4, 1984, his team published a series of papers in Science reporting the isolation of a virus they called HTLV-III from dozens of patients. They recovered the virus from 18 of 21 patients with pre-AIDS conditions, 26 of 72 patients with AIDS, and three of four mothers of children with AIDS. None of 115 healthy heterosexual subjects tested positive. The papers concluded that HTLV-III “may be the primary cause of AIDS.”
The French team had shared virus samples with Gallo’s lab during their collaboration. This raised a charged question: was HTLV-III truly an independent discovery, or was it the same virus the French had already isolated? The dispute intensified when it became clear that the American and French viruses were genetically almost identical. Both teams had filed patents for blood tests to detect the virus, and the royalties at stake were substantial.
A Presidential Settlement
The patent fight grew so contentious that it required diplomatic intervention. In 1987, U.S. President Ronald Reagan and French Prime Minister Jacques Chirac announced a formal agreement. The two governments would share the patent for the AIDS antibody test, with each side contributing 80 percent of its royalties to a new international AIDS research foundation. That foundation was also tasked with donating 25 percent of its funds to AIDS education and research in developing countries. The agreement credited both teams as co-discoverers and attempted to put the rivalry to rest.
One Name for the Virus
By the mid-1980s, the same virus had multiple names floating through the scientific literature. The French called it LAV. The Americans called it HTLV-III. In July 1986, an international committee standardized the name to Human Immunodeficiency Virus, or HIV, cutting through the confusion and, not incidentally, sidestepping the question of which team’s terminology should prevail.
That same year, researchers at the Institut Pasteur made another discovery. A second type of the virus, HIV-2, was isolated from two Portuguese patients. Suspicion of this variant had emerged in 1985, when Senegalese patients showed unusual antibody patterns more closely related to a monkey virus than to HIV-1. HIV-2 turned out to be less transmissible and largely concentrated in West Africa, but its identification confirmed that the virus had a more complex evolutionary history than initially appreciated, with origins traced to a simian immunodeficiency virus found in sooty mangabey monkeys.
The Nobel Prize and Who Was Left Out
The question of who truly discovered HIV was settled, at least officially, in 2008. The Nobel Prize in Physiology or Medicine was awarded to Françoise Barré-Sinoussi and Luc Montagnier for their discovery of the virus. They shared the prize with Harald zur Hausen, who was recognized separately for linking human papillomavirus to cervical cancer.
Robert Gallo was not included. The omission surprised many in the field, and Montagnier himself said publicly that Gallo should have been the obvious third recipient. Gallo’s contributions were significant: his lab developed the techniques for growing the virus in large quantities, which made a blood test possible, and his 1984 publications provided much of the early evidence linking the virus directly to AIDS. The Nobel committee’s decision reflected the judgment that the original isolation in Paris came first, but most scientists who lived through the era acknowledge that the American work was essential to turning a laboratory discovery into a public health tool.
Robin Weiss of University College London captured the French team’s achievement in characteristically direct terms. Without Barré-Sinoussi’s insight and laboratory skills, he said, HIV simply would not have been successfully isolated at the Institut Pasteur at that time. Her decision to check cultures every few days rather than wait for cells to multiply, a choice that went against the prevailing model of how retroviruses behaved, made the difference between catching the virus and losing it.