Knowing if PrEP is right for you

Your personal risk of HIV infection is based on a combination of factors. Some of these are personal in nature, such as:

  • Whether or not you’re having anal and/or vaginal (or frontal) sex
  • Whether you have a regular monogamous partner or multiple anonymous or casual partners
  • The HIV status of your sexual partners – i.e. if they are HIV-negative, are HIV-positive with an undetectable viral load, or have an unknown HIV status
  • Whether or not you effectively and consistently use condoms during anal and/or vaginal (or frontal) sex
  • Whether you use substances in combination with sex in a way that affects your ability to effectively and consistently use other HIV prevention strategies
  • Whether or not you inject drugs, particularly if you share injection equipment with others
  • For example, if someone is in a long-term, monogamous relationship with an HIV-negative partner, or HIV-positive partner with an undetectable viral load (controlled through high adherence to HIV medication), and does not use injection drugs or share injection drug equipment, they are likely at a low risk of HIV infection.

On the other hand, if someone is having anal and/or vaginal (or frontal) sex with multiple partners of unknown HIV status, or HIV-positive partners who have not attained and maintained an undetectable viral load, and does not effectively and consistently utilize condoms, they are likely at a higher risk of HIV infection. Other factors which can impact your vulnerability to HIV infection have less to do with your personal choices and more to do with structural or systemic factors. For example, certain populations within Nova Scotia experience higher rates of HIV to begin with such as men who have sex with men, people who belong to African, Caribbean, and Black populations, and Indigenous peoples.

Therefore, even though two people might make all the same personal choices regarding their sexual behaviour, some individuals might still be at a higher risk of HIV infection because there is a higher rate of HIV within the community they identify with and the sexual networks they belong to.​ If, based on your circumstances, you feel that you are at a higher risk of HIV infection, talk to a healthcare provider you trust. They can speak with you about what HIV prevention options are most suitable for you. One of those options is PrEP. Recently, Canadian PrEP Guidelines were released to help you and your healthcare provider understand if PrEP is right for you. These guidelines look at various factors to determine whether or not PrEP is the best HIV prevention option for you. The criteria differ depending on which communities or populations an individual identifies with. The full set of guidelines and eligibility criteria can be found here.

However, as an example, here are the eligibility criteria for gay, bisexual, and other men who have sex with men (MSM) and transgender women (TGW):PrEP is recommended for MSM and TGW who report condomless anal sex within the last 6 months and who have any of the following:​

  • Infectious syphilis or rectal bacterial STI, particularly if diagnosed in the preceding 12 months
  • Recurrent use of nPEP (more than once)
  • Ongoing sexual relationship with HIV positive partner with substantial risk* of transmissible HIV
  • High-incidence risk index (HIRI-MSM) risk score ≥11

PrEP is not recommended in the context of a stable closed relationship with a single partner with no or negligible risk of having transmissible HIV.​The decision as to whether or not you should start PrEP should be made within the context of a comprehensive sexual health discussion between you and a healthcare provider you trust. Additionally, the various factors determining your eligibility for PrEP might change over time, meaning that while you might benefit from PrEP now, you might not a year from now. Because of this, it is important that in addition to ongoing screening and monitoring (as laid out in the next section), you continue to have regular discussions about your sexual health with your provider to determine whether or not PrEP remains the best HIV prevention option for you.

Establishing Your HIV Status

If you and your healthcare provider determine that PrEP is right for you, the next step is to establish your current HIV status.​In order to accurately determine your current HIV status, it is important to understand window periods. A window period is the time after someone is infected with HIV within which standard HIV testing will not detect the virus. For example, the test generally used for standard HIV testing in Nova Scotia can begin to detect HIV in as early as 15-21 days, with 95% of tests being accurate after six weeks. And then in rare cases it can take up to three months for an accurate result to be returned.​Because of these window periods, there is a chance that you could receive an HIV-negative test result that may not be accurate. This might happen if your last sexual encounter or potential exposure to HIV occurred within the window period where HIV testing may not yet detect it. For example, if you had a potential exposure to HIV one week ago, standard HIV testing in Nova Scotia would not yet detect it.This is important to understand when considering taking PrEP, as it’s very important to ensure that you receive an accurate, up-to-date HIV-negative result before starting. If someone unintentionally starts PrEP while HIV-positive, it can result in issues related to medication resistance. The reasons for this are:

  • PrEP (TDF/FTC) only contains two different HIV medications (tenofovir disoproxil fumarate and emtricitabine). These two medications taken together as PrEP are sufficient to prevent new HIV infection. However, the successful treatment of HIV in someone who is already HIV-positive requires three or more different types of HIV medication (often combined in one single pill). Therefore, PrEP (TDF/FTC) on its own is not sufficient to treat HIV infection.
  • Because of this, if someone who is HIV-positive begins PrEP, the HIV will not respond effectively to the treatment and can build resistance against the medications in PrEP. If the HIV in someone’s system becomes resistance to these two medications, then these medications – which are quite common in many combination HIV treatment regimens – will no longer be effective treatment options for them. Although there are treatment options which do not contain TDF or FTC, it is not desirable to lose two common HIV medication options for treatment before someone is even diagnosed.

Because of this, your provider will likely take an extra step in determining your HIV status. In addition to standard testing, they will also evaluate you for signs or symptoms related to acute HIV infection within the last twelve weeks. These are signs and symptoms someone might experience soon after becoming infected with HIV but perhaps before standard HIV testing might return an accurate result. Because of this, they can act as warning signs that someone might be HIV-positive even though the tests don’t return a positive result. Some of these signs or symptoms include fever, fatigue, weight loss, or nausea.These symptoms are common to many other health issues and do not automatically mean you have HIV. However, given the importance of ensuring you’re HIV-negative before starting PrEP, assessing these symptoms can help provide an additional level of certainty when determining your HIV status. If you have experienced signs or symptoms related to acute HIV infection in the last twelve weeks, your provider will likely order follow-up HIV testing within the next one to three weeks just to ensure your HIV-negative result is accurate. During this time, starting PrEP should be delayed.

Finally, if it is determined that your current HIV status is negative and your provider writes you a PrEP prescription, it is important to continue to use other HIV prevention options, such as condoms, until you have taken PrEP for at least seven days for anal sex or twenty days for vaginal or frontal sex. This is to ensure that there is enough PrEP in your body to provide adequate protection against HIV infection. If you are taking PrEP on an intermittent or “on-demand” basis instead of daily, speak with your healthcare provider for more information about achieving steady levels of PrEP in the body for HIV prevention.