For most Canadians, donating blood is as easy as visiting a clinic and rolling up a sleeve.
Not so for gay men, who since the mid-1980s have been banned from giving blood.
That changed Wednesday, when Health Canada approved lifting the prohibition as long as the donor has not had sexual contact with another man in at least five years. The change is expected to take effect this summer.
The policy shift may give celibate gay men eager to tap a vein reason to celebrate. But it was met mostly with derision by critics of the ban, who argued the move perpetrates an unscientific stereotype of gay men and HIV transmission and does nothing to enhance the safety of the blood supply.
"For the vast majority of people who are affected by the ban, this policy change is actually no change," said Adam Awad, the national chairman of the Canadian Federation of Students, an organization among a coalition of groups that has advocated against the ban.
The coalition, which includes the Canadian AIDS Society, has recommended that behaviour and risk of transmission of disease be factored in to blood-donor restrictions. They argue, for example, that a straight man who has unprotected sex with multiple women is a greater threat to the sanctity of the blood supply than a gay man who has been in a long-term, monogamous relationship.
"This [new] policy assumes that if you're a man, regardless of what protections you might take, any sexual contact with another man becomes risky," Mr. Awad said. "We know that's not the case."
Canadian Blood Services, a non-profit charity that manages the blood supply in all provinces and territories outside Quebec, and Héma-Québec, which serves the same function in that province, began pushing for what they call the five-year "deferral period" for gay men in 2011.
The effort followed a 2010 Ontario Superior Court ruling that upheld the ban, but said there was insufficient evidence to support an "indefinite deferral period."
Dana Devine, vice-president of medical, scientific and research affairs at Canadian Blood Services, cast the policy shift as "a very significant change for us." She acknowledged, though, that the change would face resistance.
"We recognize that many people will feel that this change does not go far enough, but given the history of the blood system in Canada, we see this as a first and prudent step forward on this policy," Dr. Devine said. "It is the right thing to do and we are committed to regular review of this policy as additional data emerge and new technologies are implemented."
Several countries allow men to donate blood one year after having had sexual relations with another man, including Great Britain, Australia, Japan and Sweden. In South Africa, the deferral period is six months. Italy is one of a handful of countries that has no restrictions.
A blood-donor ban remains in place in the United States for men who acknowledge having had sex with another man at least once since 1977. Canada's screening process had also set the threshold at 1977.
Dr. Devine said a five-year deferral would give the organization enough time to collect data, specifically the rate of transmissible diseases found in donated blood. The data would be used to regularly review the policy and amend it as appropriate, she said.
At the same time, she said she did not expect the change to trigger a noticeably larger pool of donors, leaving critics to wonder what substantive data could be gleaned from the new policy.
"We do not anticipate that this will bring a large number of gay men forward to the blood-donor pool," Dr. Devine said.
Researchers at the University of California found in 2010 that if the ban in the United States were replaced by a five-year deferral, an additional 71,218 pints of blood would be donated each year.
The Canadian AIDS Society, which called the change "a good first step" that does not go far enough, was optimistic about the impact the change could have on the donor pool.
Monique Doolittle-Romas, the chief executive officer, said people who refused to donate because of the blanket ban would now reconsider.
Still, she said her group would intensify its efforts to push for a screening process based on donor behaviour rather than sexual orientation.
When a person gives blood, the donation is typically tested within 24 hours for HIV and several other infectious diseases, including hepatitis B and C, West Nile virus, syphilis and the human T-cell lymphotropic virus HTLV-I and II.
Since the 1980s, when the ban took effect, tests have become much more sensitive and accurate. The organization employs nucleic acid and antibody tests for HIV that are considered state of the art.
Of the 901,640 units of blood collected by Canadian Blood Services last year, fewer than five were found to be infected with HIV, according to the organization. A unit is the equivalent of 450 millilitres.
Fewer than 250 of the roughly 900,000 donations annually – or about 0.03 per cent – test positive for an infectious disease, according to the organization.
Hundreds of Canadians were infected with HIV and hepatitis C through blood transfusions in the 1980s before rigorous tests were implemented.
Helen Kennedy, executive director of Egale Canada, a gay-rights advocacy group, said the advances in blood testing make any deferral policy antiquated.
"It's still a discriminatory process," Ms. Kennedy said. "They're saying that a person's sexual orientation and gender identity is reason enough to have a five-year deferral. It's no different than an indefinite deferral."
In the United States, where the Food and Drug Administration is facing growing public pressure to lift the ban, the agency insists its policy is grounded in statistics.
Men who have sex with men accounted for 61 per cent of all new HIV infections in the United States in 2010. The largest increase was found in homosexual males ages 13 to 24, the population the agency says is most likely to donate blood.
Francine Proulx-Kenzle, president of PFLAG Canada, a support group for gays and lesbians, said any deferral could be viewed as discriminatory.
But she said she is heartened by Canadian Blood Services' openness to reviewing its policy and making adjustments.
"Sometimes going step by step is a result that is more lasting," Ms. Proulx-Kenzle said. "You get everyone on board and you get a result that becomes part of who we are as a society."