The Food and Drug Administration on Tuesday proposed changes that would allow gay men to become blood donors if they haven't had sex with other men for at least a year.
The move would alter the long-standing prohibition on men who have had sex with other men at any time since 1977 from donating blood.
That ban has been in effect since the height of the AIDS epidemic in the mid-1980s, and was designed to isolate its spread from the high-risk population of gay men.
The Centers for Disease Control and Prevention, in a recent report, said that men who have gay sex represent about 2 percent of the U.S. population. That report also noted that in 2010, 63 percent of all new infections from HIV, the virus that causes AIDS, were among men who have sex with men.
The FDA proposal announced Tuesday falls short of what some advocates had hoped for—a total removal of the ban. But Peter Marks, deputy director for the FDA's Center for Biologics Evaluation and Research, said the agency will continue to reconsider its policies.
The FDA said it will issue the proposed change for public comment in 2015. The agency said it will rely on donors' questionnaires to determine if they are eligible to give blood. Currently, blood donations are screened for HIV, but the FDA has noted that while those tests are "highly accurate" they "still cannot detect HIV 100 percent of the time."
The one-year deferral for blood donations by gay men has long been proposed by the American Red Cross, America's Blood Centers and AABB, which was formerly known as the American Association of Blood Banks.
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The Williams Institute, a think tank at UCLA Law School, said on the heels of the announcement that such a change "could add about 317,000 pints of blood" annually to the nation's supply, an increase of between 2 and 4 percent.
"A modification of the current blood ban to a 12-month deferral policy will increase the number of eligible donors by over 2 million men," the Williams Institute said.
In a statement Tuesday, FDA Commissioner Margaret Hamburg said: "Over the past several years, in collaboration with other government agencies, the FDA has carefully examined and considered the available scientific evidence relevant to its blood donor deferral policy for men who have sex with men, including the results of several recently completed scientific studies and recent epidemiologic data."
"Following this review, and taking into account the recommendations of advisory committees to the U.S. Department of Health and Human Services (HHS) and the FDA, the agency will take the necessary steps to recommend a change to the blood donor deferral period for men who have sex with men from indefinite deferral to one year since the last sexual contact," Hamburg said.
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Hamburg also said the proposal is consistent with the recommendation of an independent advisory panel "and will better align the deferral period with that of other men and women at increased risk for HIV infection."
She said the FDA has already taken steps to implement a national blood surveillance system that will help the agency monitor the effect of a policy change and further help to ensure the continued safety of the blood supply.