An estimated 40.8 million people are living with HIV worldwide, and the virus claimed about 630,000 lives last year, according to new global health figures released as the world observed the 37th World AIDS Day on Sunday. The annual commemoration, held every 1 December since 1988, brings together scientists, health workers, families and advocates to honour victims and renew the push to end one of the deadliest epidemics in modern history.

Since the start of the crisis, HIV has infected about 91.4 million people and caused approximately 44.1 million deaths. Despite decades of scientific advancement, experts warn that progress could be at risk as several major donor nations scale back support for international HIV programmes.

The global response to HIV began gaining momentum in the early 1980s, when US health officials identified a mysterious and fatal illness among young gay men. The disease, later understood to be caused by HIV, soon spread across different communities, from people who used drugs to haemophiliacs and blood transfusion recipients. Europe launched its first AIDS surveillance system in 1984, and by late 1985 HIV testing became available in the UK.

A turning point came in 1996 with the introduction of highly active antiretroviral therapy, or HAART, a three-drug combination that suppressed the virus and restored immune function. This breakthrough sharply reduced AIDS-related deaths in countries able to afford the treatment and shifted HIV from a near-certain death sentence to a chronic but manageable condition.

In 2003, the United States introduced the President’s Emergency Plan for AIDS Relief (PEPFAR), a landmark $15 billion programme aimed at high-burden countries. As of 2025, PEPFAR has been credited with saving more than 26 million lives across 50 nations, making it the largest single-disease global health programme in history.

Scientific progress continued into the next decade. In 2011, researchers confirmed that antiretroviral therapy significantly reduces the risk of transmitting HIV. A year later, US regulators approved Truvada as the first drug for pre-exposure prophylaxis (PrEP), followed by the EU in 2016. PrEP has since become a cornerstone of prevention, shown to reduce infection risk from sex by about 99% and from injections by roughly 74%. These tools helped drive HIV diagnoses among gay and bisexual men in the UK down by two-thirds between 2015 and 2020.

But global gaps remain. The UN’s 90-90-90 targets—set for 2020 and aimed at ensuring that 90% of people with HIV know their status, receive treatment, and achieve viral suppression—were fully met by only 19 countries. Sweden was the first to reach the milestones in 2016.

Recent advances, including a twice-yearly PrEP injection approved in the EU in 2024, have been hailed as potential game-changers. Plans are underway to bring generic versions to lower-income nations by 2027.

This year, however, health agencies have sounded the alarm over abrupt US aid freezes and funding reductions from several European governments, including the UK, Germany and France. Experts warn the cuts threaten to reverse gains in HIV prevention and treatment, especially in Africa, which accounts for more than two-thirds of all infections.

As World AIDS Day is marked once again, global health leaders stress that decades of progress cannot be sustained without consistent international support.