While the cost of HIV prevention drug PrEP is high, the cost of treating someone with HIV is higher.

That's why proponents say covering the HIV prevention pill could be economically smart. But with a price tag of almost $1,000 a month, it could be a hard sell.

The drug Truvada has been used to treat HIV for over a decade, but recent clinical trials show that if taken daily, it can also reduce the risk of getting HIV by over 90 per cent. In this case, Truvada is used as pre-exposure prophylaxis—also known as PrEP.

PrEP has proven especially beneficial for groups at high-risk of acquiring the virus, including men who have sex with men, sex workers, and those with an HIV-positive partner.

But a lack of awareness and a stigma attached to the drug, topped by its extraordinary price, has left many who want access to it in the dark.

Right now, the only province that covers PrEP is Quebec, where specialized sexual health clinics make it available to anyone at risk of getting HIV.

San Patten, an HIV research consultant, says covering the cost of PrEP makes sense for economic and social reasons (CBC)

Those on the frontlines of HIV prevention say covering the cost is socially and economically smart. Other provinces would be well-advised to follow Quebec's example says San Patten, an HIV research consultant in Halifax.

"Our provincial governments need to put it on our formulary and have it covered by our public healthcare system so that in the long run we're saving money," she says.

The numbers

While PrEP costs up to $12,000 a year, the cost of treating someone with HIV can be up to $24,056 a year, according to a study published in the Canadian Journal of Infectious Diseases and Medical Microbiology last year.

There are variables to consider, including how many people would be taking PrEP and for how long. HIV treatment, though, is for life.

Another way of taking PrEP is the "on-demand" strategy. This is where someone takes PrEP 24 hours before the first sexual encounter, every 24 hours during the sexual activity, and 24 hours after the last sexual encounter.

The study concludes that an "on-demand" PrEP strategy could save over $800,000 for each person who avoids infection.

Meanwhile, the Canadian AIDS Society estimates every new person diagnosed with HIV costs $1.3 million in direct and indirect economic costs over their lifetime. That means the 2,044 new HIV infections in Canada in 2014 alone will have a lifetime cost of more than $2.6 billion.

Dr. Tim Matheson says the rationale for supplying PReP is similar to the logic for widespread vaccination (CBC)

But Dr. Tim Matheson, a family doctor in Nova Scotia, says it may require a "shift in paradigm" for public drug plans to cover PrEP.

"[We are] financially strapped in health care," says Matheson. "Having said that, it becomes a discussion about how much do you pour into prevention versus disease management."

He compares the treatment with vaccines.

"Basically what we're talking about is herd immunity. We give people vaccines with the understanding that if we inoculate enough of the population then we're going to minimize the prevalence of the disease, so it's sort of the same strategy."

Who covers it?

Right now, those who take PrEP are generally covered by private health insurance. But even insurance companies aren't entirely sure what to do with PrEP.

Medavie Blue Cross, Atlantic Canada's biggest insurance provider, told CBC News it received a submission from the drug manufacturer to evaluate PrEP and is in the process of doing so. Until then, it won't be covered.

Blue Cross Ontario says it doesn't cover "preventative" drugs, while Manulife and Great West Life say some of their plans cover it, but there may be exceptions.

Matthew Numer is a professor of health promotion at Dalhousie University. He's been taking PrEP for close to nine months.

"There was a lot of research, finding out whether insurances cover it, and so on," he says. "I was lucky that mine did, but I know a lot of other people that would go on it but simply can't."

Davey Dow says his attempts to get PReP have left him discouraged

Davey Dow, a gay man in Halifax, is one of those people. His attempts to start taking PrEP have left him discouraged.

"Somebody like me, who was a student, makes minimum wage basically, doesn't have a lot of disposable income, but wants to kind of take that extra step or precaution in protecting themselves, it's not really realistic," he says.

Recommendations coming

Some public health authorities and policy makers are hesitant to talk about PrEP while they await recommendations from a review of the drug by the Canadian Agency for Drugs and Technologies in Health, an independent organization.

These reviews help determine if drugs should be eligible for public reimbursement, and the agency is expected to give its recommendations for PrEP this fall. That includes determining whether it makes economic sense to cover it.

But the agency's recommendations aren't binding. Each province will need to make its own decisions about PrEP—and with health care systems across the country strapped for cash, PrEP may not be a priority.

Matt Numer, a professor at Dalhousie University, has been taking PrEP since before it was approved in Canada (CBC)

But some say it's about more than just the bottom line.

"If we had a similar pill for, say heart disease, or other diseases that have a behavioural component to it, there would be no question. People would be lined up around the corners," Numer says.

Stigma still there

PrEP's relationship to HIV, and its associated stigma, has muddied the waters, he says.

"Because it's related to sex people always have a very strong opinion—that people should just behave and do what is pure and right." he says.

"Then when you put HIV into the mix, people aren't sure. They get worried or scared that this is going to somehow create bad things."

HIV infection rates in Canada hover around 2,000 a year. (Public Health Agency of Canada)

'A disease we can eliminate'

In the past decade, rates of HIV infection have hovered around 2,000 a year in Canada. While some believe condoms are a better and cheaper approach to prevention, advocates say there's need for another tool.

According to Patten, recent efforts to continue promoting safe sex haven't put a dent in HIV rates.

"People who want to go on PrEP probably have problems with condom use in the first place. So I think it's just acknowledging that we need a full package of tools to help us prevent HIV," she says.

"This is a disease that we can eliminate."