This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
On June 5, 1981, the U.S. Centers for Disease Control's Morbidity and Mortality Weekly Report described five cases of Pneumocystis pneumonia in previously healthy gay men in Los Angeles, a disease so rare it normally appeared only in patients whose immune systems were already devastated by chemotherapy or advanced age. Nobody involved yet knew a virus was responsible, let alone which one. For nearly two years the syndrome had a name but no known cause, and briefly, before wider case patterns emerged, a stigmatizing one: gay-related immune deficiency, retired in 1982 once cases turned up in hemophiliacs, transfusion recipients, and heroin users, plainly unconnected to sexual orientation. Finding the actual cause became one of the most closely watched, and most bitterly contested, chases in twentieth-century medicine.
In 1983, a team at the Institut Pasteur in Paris led by Luc Montagnier and Francoise Barre-Sinoussi isolated a new retrovirus from a patient's swollen lymph node and called it LAV. They sent a sample to Robert Gallo's laboratory at the U.S. National Cancer Institute for comparison, standard scientific collegiality between labs racing toward the same target. In 1984, Gallo's team announced its own isolation of a retrovirus, which it named HTLV-III, declared it the definite cause of AIDS, and, critically, published a reliable antibody blood test built from it, the tool that let blood banks start screening donations and let patients get a diagnosis at all. For the general public, informed largely through a U.S. government press conference, Gallo's announcement was the discovery of the AIDS virus.
The French team disagreed, and had reason to: HTLV-III looked, on close genetic comparison, suspiciously identical to LAV, the sample the Pasteur lab had sent Gallo's lab itself. What followed was not a polite academic dispute conducted through journal letters. It became a five-year international incident: a patent fight over the blood test's royalties, a formal 1987 diplomatic settlement personally brokered between French Prime Minister Jacques Chirac and U.S. President Ronald Reagan that split the money and credited both teams jointly, a U.S. Congressional investigation, and an Office of Research Integrity inquiry into Gallo's laboratory practices. A 1991 scientific review concluded that Gallo's isolate had in fact been contaminated by the French sample, undercutting the independent-discovery claim his 1984 announcement had made, though Gallo continued to maintain his team's work stood on its own merits regardless of contamination in one particular sample. The virus itself was renamed, neutrally, human immunodeficiency virus (HIV) in 1986, retiring both labs' competing names along with the argument over whose name should stick.
Science does not usually resolve a priority dispute by handing out a prize twenty-four years later, but in 2008 the Nobel Committee did exactly that, awarding the Prize in Physiology or Medicine to Montagnier and Barre-Sinoussi alone for the discovery of HIV. Gallo was left off entirely, a decision that reopened the old argument rather than closing it: his defenders noted that his laboratory's blood test, not the Pasteur isolate itself, was what actually let the world test for the virus at scale, and that the Nobel citation, in crediting discovery, arguably wrote his contribution out of the story it was telling. This atlas carries the discoverer credit and Gallo's dissenting claim as two separate, sourced records rather than as a single tidy sentence, on the theory that a dispute this well documented deserves to be readable as a dispute, not smoothed into an outcome. It is also worth remembering what all the argument over credit tends to obscure: within three years of that first, unnamed cluster of five pneumonia cases in Los Angeles, someone had found the actual cause, badly enough, and fast enough, that a blood test existed before the decade was out. The disagreement over whose name belongs on the discovery does not change what the discovery, whoever gets full credit for it, made possible.