AIDS Blood Test Approved: Saving Millions of Lives

Before March 1985, every blood transfusion in America carried an invisible gamble. The AIDS epidemic had been killing patients since 1981, and doctors knew the virus was transmissible through blood, but they had no way to screen donations. The FDA's approval of the first commercial HIV blood test on March 2, 1985, closed a terrifying gap in the blood supply that had already infected thousands of hemophiliacs, surgical patients, and newborns. The test, an enzyme-linked immunosorbent assay (ELISA) developed by Abbott Laboratories, detected antibodies to HTLV-III (later renamed HIV) in blood samples. It could not diagnose AIDS directly — it identified immune system exposure to the virus, which meant a positive result required confirmation by a more specific Western blot test. But for blood bank screening, the ELISA's sensitivity was the critical factor: it caught virtually all contaminated donations at a cost of roughly $3 per test. The crisis the test addressed was staggering in scale. The Centers for Disease Control estimated that between 1978 and 1985, approximately 29,000 Americans received HIV-contaminated blood transfusions. Hemophiliacs, who required regular infusions of clotting factor derived from pooled blood donations, were devastated: roughly half of the 20,000 hemophiliacs in the United States contracted HIV through contaminated blood products. Ryan White, an Indiana teenager with hemophilia who contracted HIV from a blood transfusion, became the most visible face of this crisis. Blood banks began screening all donations within weeks of the FDA approval. The American Red Cross, which collected about half the nation's blood supply, implemented testing by April 1985. The impact was immediate: new transfusion-related HIV infections dropped to near zero within a year. The test also raised difficult questions. People who donated blood now received results they had not sought, creating an unintended mass screening program. Some blood banks became de facto HIV testing sites as at-risk individuals donated specifically to learn their status. The ELISA blood test is estimated to have prevented hundreds of thousands of transfusion-related HIV infections worldwide in the four decades since its approval.