New science is giving us more options to prevent HIV.
In acknowledgement of Sexual and Reproductive Health Awareness Week, it is fitting to talk about the great advances that have been made in preventing the sexual transmission of HIV.
For about 30 years, sex educators have trained most of us to know that condoms are the most effective form of protection against HIV and other sexually transmitted infections.
But today, we have many more tools in the HIV prevention toolbox. Medication that can reduce the risk of an HIV-negative person becoming infected when taken before an exposure (PrEP) or after an exposure (PEP) to HIV. Treatment that can dramatically reduce the risk of an HIV-positive person passing on the virus. Strategies that can further reduce the risk of infection when combined with another prevention option.
More choices are always welcome. But with more choices, there are more factors to consider.
PrEP, or pre-exposure prophylaxis, is the ongoing use of anti-HIV medications by an HIV-negative person to reduce their risk of HIV infection. Several studies show that the use of a daily pill called Truvada as PrEP can reduce the risk of HIV transmission by over 90% if used consistently and correctly. But if the pill isn’t taken regularly, it’s less effective.
PEP, or post-exposure prophylaxis, is the use of anti-HIV medications by an HIV-negative person to reduce the risk of HIV infection from a single exposure to HIV. It needs to be started as soon as possible (but generally within 72 hours) after an exposure and involves taking medications every day for a full month. PEP is not meant to be used as a regular method of preventing HIV infection, but only in the case of an emergency.
Treatment as prevention is a secondary benefit of antiretroviral treatment (ART), the medication used by people living with HIV. In addition to improving the health of an HIV-positive person, ART can reduce the amount of HIV (viral load) in the bodily fluids to undetectable levels – lowering the risk of HIV transmission through anal and vaginal sex. Several studies show that ART can reduce the risk of HIV transmission by more than 90% if used consistently and correctly.
Keep in mind that these three prevention strategies only reduce the risk for HIV; they have no effect on the risk for other sexually transmitted infections (STIs). And since the presence of STIs can increase the risk of getting or passing on HIV, regular STI testing and (if needed) treatment is important to make sure these prevention strategies are as effective as possible.
To reduce the risk of other STIs, condoms – both external (“male”) and internal (“female”) – are still the most effective prevention strategy. That doesn’t mean they’re perfect, against STIs or HIV. Research suggests many people struggle to use condoms effectively, making its practical effectiveness against HIV infection, even when used consistently, anywhere from 70 to 80%. Even if a condom is used perfectly, some STIs can still be transmitted because a condom doesn’t cover all the parts of the body where these infections can be found. But if a condom is used correctly and doesn’t break, slip or leak, then there is no risk of HIV transmission because an exposure to HIV cannot occur.
All prevention strategies have their own advantages and limitations. But what they all have in common is that none of them are effective unless they are used correctly and consistently. How well a particular prevention strategy works can vary from person to person, so it’s important for individuals to choose the tools that work best for them.