A new Canadian guideline on HIV prevention emphasizes the patient’s role in decisions related to pre-exposure prophylaxis (PrEP) and postexposure prophylaxis (PEP) prescriptions. It also highlighted the expanded range of such treatments, which includes an injection given every 2 months.

The updated guideline, which replaces the 2017 guideline, is intended to help health professionals and the medical community at large reach more people who could benefit from PrEP and PEP, lead author Darrell Tan, MD, PhD, an infectious disease physician at St. Michael’s Hospital in Toronto, told Medscape News Canada.

“It does require frontline clinicians to bring it up, to get more comfortable talking about sex, drugs, things that you may not always feel you need to talk about” with patients, he said. “Yet they’re really important and very real parts of people’s lives.”

The updated guideline was published on December 1 in CMAJ.

PrEP on Request

The rate of new HIV diagnoses in 2024 was 5.7 per 100,000 population, according to government data. This figure excludes Quebec, as is common in Canadian health statistics. The Canadian Prairies continue to have the highest rates of new HIV diagnoses, with 2024 figures of 19.5 per 100,000 for Manitoba and 18.6 per 100,000 for Saskatchewan.

The new guideline is based on systematic reviews of evidence for PrEP and PEP. It also incorporates suggestions from organizations that represent key populations affected by the HIV epidemic in Canada.

The document provides 31 recommendations and 10 good practice statements. Key among them is the recommendation to honor patients’ requests for PrEP based on their own self-assessed estimate of HIV exposure.

Many patients may not fully disclose their HIV risk because of feelings of “shame, medical mistrust, and structural barriers linked to homophobia, transphobia, racism, colonial practices, HIV stigma, and other forms of discrimination,” the authors wrote.

“Providing PrEP to those who request it decreases such barriers. Providers should make this safe and effective intervention available to the widest possible array of users, rather than ‘gatekeeping’ access,” they wrote.

Sexually active adolescents and adults and patients who inject drugs should be counseled regarding PrEP and PEP, the guideline also stated.

Health Canada approved long-acting injectable cabotegravir (CAB-LA) for PrEP last year. This treatment can be given in as few as six injections per year, instead of daily pills. 

Healthcare and other leaders also have a responsibility to create conditions in which everyone feels comfortable talking about HIV, said Tan. “It wouldn’t be as heavy of a lift for the frontline clinician to talk about something if there’s already been tons of messaging.” For example, years of messaging from the medical community about the influenza vaccine succeeded in making the public aware of the benefits of taking steps to prevent infection, said Tan.

Levels of Evidence

In creating and updating the guidelines, the authors categorized evidence as strong or weak. In some cases, the researchers had to make recommendations based on studies of participants outside the intended population.

For example, the guideline includes strong recommendations based on high-certainty evidence for use of the CAB-LA injection in patients whose risk for HIV infection is associated with sex with men. This recommendation is based on studies of patients in this group.

But robust clinical studies have not examined whether CAB-LA prevents the spread of HIV through shared needles. The authors thus made an assessment based on the available studies, and the resulting advice is characterized as a “weak recommendation based on very low-certainty evidence.”

Weak recommendations sometimes are understood incorrectly as negative statements about the corresponding interventions, said Tan. The weak recommendation about CAB-LA for drug users is an example. “The panel ultimately felt [that it] could be appropriately used, recognizing it’s not a strong recommendation because there isn’t actually direct evidence proving its efficacy in that setting,” Tan said. “But we thought it was really important from an equity perspective,” given the rates of HIV diagnosis in Manitoba and Saskatchewan.

Spurring Needed Conversations

The updated guideline reflects a major expansion in knowledge about how well PrEP works for different groups, Andrew Eaton, PhD, associate professor of social work at the University of Regina, told Medscape News Canada. Eaton, who was not involved with the update, conducts research on harm reduction and HIV prevention in Saskatchewan.

Health Canada approved the first PrEP drug combination in 2016, a little more than a year before the first guideline on HIV prevention appeared. In 2017, PrEP still was considered experimental, Eaton said.

“Since that time, many clinical trials have been completed with so many key populations that have found that across the board, regardless of PrEP product, it’s safe, tolerable, and efficacious,” Eaton said.

The initial guideline understandably took a cautious approach, given how new PrEP was for the Canadian medical community. “The new guidelines are written with the spirit of prescribing PrEP to all who want it,” Eaton said.

The more active tone may help spur needed conversations with patients at risk for HIV infection, Eaton said. His research has found that many patients at risk for HIV have little knowledge of PrEP and may benefit from outreach. Eaton is working on an effort to provide education, PrEP, and HIV testing in areas of high use of injected drugs.

HIV diagnoses in the Prairies are mostly associated with drug use, Eaton said. “By and large, people in the Canadian Prairies are using drugs alone. They’re hiding it. They don’t want anyone to know about it, whereas in Vancouver, Montreal, Toronto, and Halifax, people have a bit more of a network. They might use drugs with a few people they know. They might have a social worker they really trust,” Eaton said.

Stigma and discrimination are common in all provinces, and patients rarely speak openly about their current drug use, Eaton said. “But it’s not as isolating and lonely as it is in Saskatchewan.”

The guideline was supported by grants from the Canadian Institutes of Health Research (CIHR), with in-kind support from the CIHR Pan-Canadian Network for HIV and Sexually Transmitted and Blood-Borne Infections clinical trials research. Publication costs were offset by unrestricted educational grants from Gilead Sciences and ViiV Healthcare. Funders had no influence on the guideline process or development of recommendations. Tan reported receiving funding from CIHR and a Tier 2 Canada Research Chair in biomedical HIV and sexually transmitted infection prevention in support of the current manuscript. He also reported receiving research funding from Gilead Sciences, GlaxoSmithKline, and ViiV Healthcare for participation in industry-sponsored studies. Eaton reported an honorarium from Gilead Sciences for the presentation of independent scientific material and financial support from AbbVie for a research study.

Kerry Dooley Young is a freelance journalist based in Washington, DC. She has reported on medical research and healthcare policy for more than 20 years.