6 Ways to Prevent HIV, Including a Promising Injectable Medication

We haven't found a vaccine to prevent HIV. When scientists do, it might not be fully effective right away, and while that may sound a bit gloomy, there are other known strategies to preventing HIV, including a potential injection.

Currently Known Ways to Prevent HIV

1. Practice Safer sex. If you do have sex, use protection and use condoms. Get tested for HIV. Get tested with your partner(s). Have check-ups for STDs and have these STDs treated.

2. Avoid Re-Using Needles. Anyone using needles should only use clean needles, whether in a hospital or if self-injecting.

3. Get Treated for Prevention. Someone HIV+ who is fully treated for HIV and has a low or non-detectable viral load (amount of virus in their blood) is unlikely to infect anyone else. With HIV, treating yourself means not just helping yourself, but also reducing the risk of transmitting the virus to your partner.

There's also pre-exposure prophylaxis and post-exposure prophylaxis. Just like treating HIV with medications helps prevent HIV from spreading, giving medications to those potentially exposed helps prevent HIV transmission. 

4. Pre-Exposure Prophylaxis (PrEP) lets those who are HIV-negative, but at risk for HIV, take a pill daily to reduce their chance of becoming HIV-positive. They usually take a once-a-day pill like Truvada which contains two HIV medications, tenofovir and emtricitabine. This is not as many medications as in a full regimen, which contains at least three medications. Taking this pill consistently daily can drop the chance of acquiring HIV by 92 percent.

It's less effective if not taken every day and everyone is capable of forgetting. It's hard to remember to take a pill every day. It doesn't replace the need for safe sex (or safe needles), but reduces the risk in those at high risk for acquiring HIV. This means taking a pill daily for a long time but the pill chosen fortunately does not have many side effects for most people.

Those who take PrEP know they are at risk for HIV. This may include being the regular partner of someone who has HIV. This may include gay men who recognize they may be at risk from a new partner and want to minimize this risk.

It's still possible to get HIV when taking PrEP even when taking the pill daily, but the risk is much lower.

You'll need to check-up with a doctor every three months if you take PrEP.

5. Post-Exposure Prophylaxis (PEP) protects those who have already been potentially exposed to HIV reduce the chance of acquiring HIV. In this case, someone who has been possibly exposed seeks care immediately, hopefully at least within 24 hours (and not later than 72 hours).

You can get PEP from your doctor's office, an emergency department, an urgent care clinic, or an HIV clinic. It's important to seek help immediately if you've been exposed. If your healthcare provider has any questions, they can call: the CDC-supported Clinical Consultation Center at (888) 448-4911.

Exposure to HIV could be from:

  • an accidental needle stick by a healthcare worker helping an HIV+ patient
  • rape, sexual assault
  • unprotected and consensual sex with an HIV+ partner
  • having HIV+ blood (or some other body fluids) splash in your eyes or mouth
  • having an open wound or scrape being splashed with HIV+ blood (or some other body fluids) 
  • sharing needles (or non-sterilized and invasive medical supplies) with someone who is HIV+
  • very rarely: an inadvertent blood transfusion with HIV+ blood

Exposure does not include casual contact. It does not include kissing or being spit on.

Sometimes PEP includes two drugs, but depending on the risk and availability of drugs, PEP may include three drugs, a full HIV medication regimen. This treatment with medications for HIV continues for one month.

Although those who take PEP have already been potentially exposed, most potential exposures do not lead to infection. The risk is less than 1 in 100 for most types of exposures. Even before PEP, most needlesticks and sexual encounters, even when the person was known to be HIV+, did not lead to HIV transmission. The risk depends on the viral load (how much virus is in the blood). However, needlesticks lead to infections in about 2.3 out of 1,000 exposures. The risk from sex depends on what type, with receptive anal intercourse being the riskiest (13.8 per 1,000), while other types of sex carry a risk of about 4-11 per 10,000 encounters.

PEP is not 100 percent effective, so someone taking PEP after an exposure should use protection (condoms) with a partner to avoid any risk.

The cost of PEP HIV medications may be a problem. If you are a sexual assault survivor or your exposure is the result of another crime and need help in the US paying for these medications, please contact victim support services in your state. For others, there are other means of acquiring assistance quickly if you do not have insurance. Cost should not delay care as it is very important that these medications are taken very soon after exposure.

There May Be A New Way to Prevent HIV

6. Injectable, Long-Acting HIV medications may be another way of preventing and treating HIV. This isn't a vaccine. Instead, it's the same as the pills taken for treatment, PEP, or PrEP, but injected. It's on the horizon; it's not here, but it may make a huge difference in how HIV can be treated and prevented.

Researchers have worked to find a way for both treatment and prevention to be long acting. There isn't yet an approved long acting drug, but it's something in the works that may happen not too far into the future. Taking a pill every day is hard. Anyone can forget. When we forget pills, our drug levels drop and resistance can develop. If resistance develops with HIV, the drugs will stop being effective. New drugs would have to be started, but resistance can then wipe out using whole groups of medications and there are only so many classes, or groups, of HIV medications. It's important to avoid developing resistance.

If a drug lasted for weeks or months, it wouldn't be so hard to make sure that the treatment was taken. Clinics could even administer the treatment for those who had difficulty taking their medications. In that way, a long acting drug could help keep people healthier, on their medications, and possibly avoid resistance.

Injectable HIV medications may last for four to eight weeks or even longer. It had been hoped they would last 12 weeks, but they appear to wear off too quickly.

The drugs used were the same types of drugs we use in pills, like integrase inhibitors and NNRTIs (non-nucleoside reverse transcriptase inhibitor). The difference is that these drugs were formulated to be injected. These injected medications were able to last a lot longer. Instead of wearing off after a day or so, the drugs can remain at a high enough level for a month or two.

It will take time to see how this method works. We will see how it works in different people—different ages, genders, on different medications, and with different medical histories.

It's very important that the drug levels stay high enough in blood and other parts of the body. If drug levels in the blood (and other parts of the body) drop too low, the virus can mount a return. This can risk resistance as resistant strains would be selected for. So just like it's important that pills are taken daily, it's important that the injectable drugs don't create the same problem and wear off too quickly in some people. This will need to have to account for times when someone chooses to discontinue a drug—such as because of side effects—and drug levels may slowly drop after the drug is stopped.

We will also see if there are side effects to injections that are a problem. The injections have been given in the glutes, rather than in the arm, as there's more to be injected than in a regular flu vaccine. These injections were also painful for some people.

All drugs take lots of testing to make sure they work as we expect. Even though the drugs used are familiar, the new formulation will be tested extensively. So far studies have shown this method to be as good as pills—and no resistance has been detected. A lot of people have reported liking this regimen.

Such injectable drugs could be used for prevention and treatment.

At some point, those at high risk for HIV could receive a shot every one to two months to protect them. This wouldn't be a vaccine, but rather, like PrEP, it would be just enough drugs to avoid letting HIV infect someone. This might not be perfect: in studies at least two people have been infected, but many others were protected.

Others could go from having to worry about taking medications every day to only needing to visit their clinic for a shot every one to two months. This could be a whole new way of treating HIV. It might be really helpful in areas where resources are limited—and disasters are more common. This way if people have to suddenly seek refuge, leaving their homes and clinics, they could be alright for a month or two without their pills. It might also help with clinics that have problems stocking large amounts of drugs and attempting to provide adherence counseling. In this way, there may be new options for treating HIV effectively and effective treatment can prevent transmission and stop HIV, entirely.

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