OnPrEP : Everything You Need to Know About HIV Prevention

What is PrEP?

PrEP (Pre-Exposure Prophylaxis) is a medical strategy where people who do not have HIV take antiretroviral medication to prevent HIV infection before potential exposure. Currently, the most common forms of PrEP include:

• Daily Oral Pills:
  • Truvada (Emtricitabine/Tenofovir Disoproxil Fumarate, or FTC/TDF) – Approved for all individuals at risk of HIV through sex or injection drug use.
  • Descovy (Emtricitabine/Tenofovir Alafenamide, or FTC/TAF) – Approved for men and transgender women but not for people at risk through vaginal sex.
• Long-Acting Injectable PrEP:
  • Apretude (Cabotegravir Injection) – Approved for use every two months, eliminating the need for daily pill adherence.

OnPrEP is designed for people who are at significant risk of HIV exposure, including men who have sex with men (MSM), transgender individuals, heterosexual individuals with HIV-positive partners, and people who inject drugs (PWID).

How Effective is PrEP?

PrEP is highly effective at preventing HIV when taken correctly and consistently. Studies show that daily oral PrEP reduces the risk of HIV infection by about 99% when used as prescribed, making it one of the most reliable prevention methods. Injectable PrEP (Apretude) offers even greater protection due to its sustained presence in the body, ensuring adherence without the need for daily pills. For people who inject drugs (PWID), PrEP has been shown to reduce the risk of HIV infection by 74% when taken consistently.

The key factor in PrEP’s effectiveness is adherence—missing doses, especially with oral PrEP, can significantly lower its protective effects. Injectable PrEP helps address this challenge by eliminating the need for daily medication, ensuring continuous protection. Regardless of the form of PrEP used, staying committed to the prescribed regimen is essential to maximizing its ability to prevent HIV.

Who Should Consider Taking PrEP?

PrEP is recommended for individuals at high risk of HIV exposure, including:

1. Men Who Have Sex with Men (MSM) – This group remains at the highest risk in many regions, particularly if engaging in condomless sex or having multiple partners.
2. Heterosexual Men and Women – Especially those with HIV-positive partners who are not virally suppressed.
3. People Who Inject Drugs (PWID) – Those who share needles or injection equipment.
4. Sex Workers – Due to increased sexual activity and inconsistent condom use.
5. Individuals in Serodifferent Relationships – Where one partner is HIV-positive and the other is negative.

OnPrEP is also recommended in certain situational risks, such as:

• People who have had a recent sexually transmitted infection (STI).
• Those who use recreational drugs during sex (chemsex).
• Individuals who travel to high HIV-prevalence regions and engage in unprotected sex.

How to Start PrEP?

To start PrEP, individuals must undergo a screening and assessment process, which includes:

1. HIV Testing – PrEP should never be taken by someone who is already HIV-positive, as it can lead to drug-resistant strains.
2. Kidney Function Test – Since tenofovir-based PrEP can affect kidney health, a creatinine test is needed before starting.
3. Hepatitis B & C Testing – Truvada also treats Hepatitis B, so stopping PrEP without medical guidance can worsen Hepatitis B infection.
4. STI Testing – Many providers also recommend screening for gonorrhea, chlamydia, and syphilis before initiating PrEP.

Daily vs. OnPrEP On-Demand PrEP

There are two main dosing strategies:

• Daily PrEP – Recommended for all individuals, particularly for those at continuous risk.
• OnPrEP On-Demand (Event-Based) PrEP – Also known as 2-1-1 PrEP, involves taking:
  • Two pills 2-24 hours before sex
  • One pill 24 hours later
  • Another pill 48 hours after the first dose
  • This method is effective for MSM but is not approved for vaginal sex or injection drug use.

Potential Side Effects and Risks

Most people tolerate PrEP well, but some may experience mild side effects, including:

• Nausea or stomach upset (common during the first few weeks)
• Headaches
• Weight gain or changes in appetite
• Decreased kidney function (rare, usually reversible upon stopping)
• Bone density loss (long-term concern, mainly with FTC/TDF)

Long-acting injectable PrEP (Cabotegravir/Apretude) has reported mild injection site reactions but is generally well tolerated.

Regular follow-ups every 3 months help monitor any side effects and ensure ongoing HIV and STI testing.

PrEP and Other HIV Prevention Strategies

PrEP is just one tool in HIV prevention and is most effective when combined with other protective strategies. Using condoms during sex helps prevent other sexually transmitted infections (STIs) such as gonorrhea, chlamydia, syphilis, and herpes, which PrEP does not protect against. Regular HIV and STI testing is also essential for early detection and treatment, reducing the risk of complications and further transmission. Additionally, Treatment as Prevention (TasP) plays a crucial role in HIV prevention—people living with HIV who take antiretroviral therapy (ART) and maintain an undetectable viral load (“U=U”—Undetectable = Untransmittable) cannot transmit the virus to their partners.

For people who inject drugs (PWID), needle exchange programs and access to sterile injecting equipment help minimize the risk of HIV transmission. While PrEP is highly effective at preventing HIV, it does not protect against other STIs, making safe sex practices and routine medical check-ups essential for comprehensive sexual health.

Misconceptions and Barriers to PrEP Access

Despite its effectiveness, several myths and barriers prevent wider adoption:

• “PrEP is only for gay men” – While MSM have the highest rates of use, PrEP is recommended for all at-risk populations, including heterosexual individuals and PWID.
• “PrEP encourages risky behavior” – Studies do not show significant increases in risky sexual behaviors among PrEP users.
• “PrEP is too expensive” – Many countries have insurance coverage, government programs, or generic options to make it affordable.
• “Taking PrEP means you’re promiscuous” – PrEP is simply a tool for proactive health management, just like birth control.

Global Availability and Access

OnPrEP or PrEP is widely available in high-income countries like the USA, Canada, Australia, and the UK. However, in low- and middle-income countries, availability is limited due to:

• Cost of medication
• Limited awareness and education
• Stigma against HIV prevention
• Regulatory barriers

Global health organizations, such as WHO, UNAIDS, and PEPFAR, are working to expand PrEP access, particularly in Africa and Asia, where HIV prevalence remains high.

Future of PrEP

Research is ongoing for next-generation PrEP options, including:

• Longer-acting injections (every 6 months)
• PrEP implants
• Vaginal rings for women
• Multipurpose prevention technologies (MPTs) that combine HIV and pregnancy prevention.

These innovations aim to improve adherence and accessibility.

Conclusion

PrEP is a game-changer in HIV prevention, offering near-total protection when taken correctly. While it’s not a standalone solution, it significantly reduces HIV transmission when combined with other preventive measures. Awareness, accessibility, and destigmatization efforts are key to making PrEP widely available to all who need it.

If you think PrEP might be right for you, talk to a healthcare provider today. Protecting yourself from HIV starts with knowledge and proactive health choices.

Reference

1. CDC. (2023). Pre-Exposure Prophylaxis (PrEP). Retrieved from https://www.cdc.gov/hiv/basics/prep.html
2. WHO. (2023). PrEP Implementation Guidance. Retrieved from https://www.who.int/hiv/pub/prep/en/
3. UNAIDS. (2023). Global HIV Prevention Strategies. Retrieved from https://www.unaids.org/en