MPs on the House of Commons health committee voted Tuesday to review Canada's restrictions on male blood donors who have had sex with other men.

Last June, Health Canada cleared the way for men who've abstained from sex with other men for at least one year to donate blood. But gay men who are currently sexually active remain banned.

The committee will study the scientific basis for blood donor restrictions, calling on experts to inform future policy decisions.

Canadian Blood Services, the agency that oversees the national supply of blood and blood products, along with Quebec's agency Héma-Québec, submitted a proposal to the department in March asking for waiting period regulations for men having sex with men (MSM) to be reduced from five years to one year.

Prior to 2013, there was a ban on male donors who'd had intercourse with other men. The national blood agencies and Health Canada replaced the blanket ban with a waiting period.

The shorter, one-year waiting period, which took effect nationally on Aug. 15, fell short of the Liberal Party's commitment during the 2015 election to end the practice of singling out these particular donors and requiring abstinence for a defined period of time.

In announcing Health Canada's change last June, Health Minister Jane Philpott said she recognized that shortening the waiting period was not a radical change nor sufficient for those affected.

"I would rather see Canada take a step in the right direction than stand still," the minister said.

Orlando shootings drew attention to issue

Calgary Conservative MP Len Webber's motion for the Commons health committee to study blood donor rules was delayed last June, but finally came up for a vote now that Parliament has resumed for the fall sitting.

It called for "a study this fall of the current restrictions imposed on men who have sex with men (MSM) when it comes to the donation of blood, to determine if the current ban is scientifically supported, or to determine if this restriction can either be reduced or eliminated while maintaining a safe blood supply system."

Although his interest in the issue predated June's nightclub shooting in Orlando — where the city's gay community wanted to help victims but were banned from making blood donations — the attacks prompted a dialogue about what kind of restrictions might be less discriminatory while still being effective.

Webber, a longtime advocate for organ donation who worked to set up the organ donor registry in Alberta, hopes the committee's study will bring forward scientific arguments and speed up change.

"The demand for blood can be unpredictable, but the ability to donate blood need not be. It is my hope that basing blood, organ and tissue donation safety on science alone will go a long way to ensuring that those who want to safely give life-saving donations to their fellow humans are able to do so," he wrote earlier this year on his Facebook page.

The health minister was supportive of the committee motion.

Health Minister Jane Philpott said last June that that shortening the waiting period was a step in the right direction but not a complete solution. (Nathan Denette/Canadian Press)

Even as the shorter waiting period takes hold, Canadian Blood Services continues to explore the possibility of further changes to its donor eligibility criteria, moving toward what it calls "behaviour-based screening" — trying to balance keeping the blood supply safe from sexually transmitted viruses while not discriminating against a particular group.

Sexually active gay couples who are monogamous and have been tested for sexually transmitted diseases, for example, remain subject to an automatic waiting period despite their relations being relatively low-risk.

The blood agency says there is no international consensus on an optimal deferral period for men who have sex with men, since the patterns, causes and effects of HIV infection differ by country. The United States, the United Kingdom, Australia and the Netherlands have or are implementing a one-year deferral.

Health Canada is providing $3 million to Canadian Blood Services and Héma-Quebec to:

Fund behavioural research to ensure non-discriminatory practices.

Organize an international seminar to discuss blood donor policy.

Encourage further development of technologies for blood screening.

While the committee supported Webber's motion to study blood donor restrictions, a second motion of his calling for a study of Canada's fentanyl and opioid crisis was defeated.