"By making [the drug] more accessible and more affordable to people who are at greater risk of getting HIV, then we're able to reduce the incidences of HIV," she said while making the surprise announcement, according to the Calgary Herald .

Premier Rachel Notley made the announcement on Saturday during a Pride Week event for Camp fYrefly , a retreat program for queer and trans youth.

Alberta's provincial government has announced it will cover the costs for the preventative HIV medication PrEP starting this fall.

PrEP, short for pre-exposure prophylaxis, is often sold under the brand name Truvada and is prescribed to people at high risk of contracting HIV. It's highly effective at preventing HIV transmission, according to the Centre for Disease Control. Daily use of PrEP can reduce the risk of contraction by over 90 per cent.

Gay or bisexual men, and transgender women are most likely to be prescribed the medication, according to CATIE, a source for Canadian HIV and AIDS information.

Despite the medication's effectiveness, its cost can be a significant barrier. PrEP's generic form can cost about $8.30 a day, or $250 a month, while Truvada can sometimes cost up to $1,000 a month, CBC News reports.

Alberta has the fourth-highest rate of new HIV infections in the country, according to government data. The number of cases has increased 11.6 per cent between 2015 to 2016.

Notley credited the policy change to advocacy work by health groups.

"Community health advocates in general have been asking us to move forward (on this)," Notley said on Saturday, according to CTV News.

Several other provinces currently cover PrEP under their health plans, including B.C., Saskatchewan, Ontario, Quebec, Nova Scotia and New Brunswick.

Coverage in Alberta will begin on Oct. 1 and will require a doctor's prescription.

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