Shortly after the HIV/AIDS outbreak in the 1980s, governments worldwide began barring men who have sex with men (MSM) from donating blood. At the time, blood services pointed to the higher prevalence of HIV/AIDS among MSM and the lack of a reliable test as reasons for the prohibition.

In the US, it wouldn’t be until 2015 that the rules would get eased, replacing the indefinite deferral of blood donations to one year since last having sex with an MSM partner (the policy extends to MSM partners regardless of gender). The deferment period is now three months in response to pandemic-related blood shortages. Regardless, the US remains one of the few countries that continue a blanket deferment of blood from MSM.