It is probably not dangerous for you and your partner to have condomless sex when it comes to HIV, but we’d need to know more about your health history to be sure. Here’s what we can tell you.

For people living with HIV, the most important thing is to get on anti-retroviral therapy (ART), reach viral suppression (meaning the virus can’t be detected in your blood), and stay on the medication. This is the best thing you can do for your own health and for each other’s health. If the virus in undetectable in your blood you can’t transmit it to a partner.

Some couples stop using condoms at this point; sex remains entirely safe with no chance of transmitting the virus. (But it’s a good idea to discuss this with your doctor first and only stop using condoms after the virus has been undetectable for quite a while.)

If you are not virally suppressed, you could pass the virus to your partner and vice versa. You and your partner may have the same strain of HIV, or you may have different ones. When someone who is living with HIV becomes reinfected with a different strain of the virus it’s sometimes called superinfection, which sounds scary but really isn’t.

No one knows exactly how often reinfection occurs. One study found that it happened in about 7% of people with HIV. Some experts think it’s even more frequent than that. But most cases of reinfection or superinfection are not a problem. They don’t change your health status or treatment needs.

However, some people are reinfected with a strain that is resistant to available HIV drugs. This can make it harder to stay healthy.

You also asked whether you could create a new strain. This is a really good question, but not something that anyone living with HIV really needs to worry about. Theoretically, when someone who already has HIV is infected with another strain, the two strains can combine to form a hybrid. This is called a recombinant form of the virus. Recombinant forms of the virus are part of how HIV keeps changing and can be a problem for public health. For example, it is one of the reasons it’s been so hard to create a vaccine against HIV.

The actual risk of creating a recombinant virus in this situation isn’t known; it’s a theoretical possibility that won’t necessarily happen. And it’s unclear if it would have any impact on your health if it did.

Again, what’s most important to know about this is that you can prevent reinfection and recombinant forms of infection if you and your partner continue with treatment and remain virally suppressed.

If either you or your partner are not taking ART or have not reached viral suppression, you should see a health care provider to start or change treatment. In this case, you should consider using condoms until you are both undetectable.

Also, if either of you are having sex outside of this relationship, you should consider using condoms to prevent other STIs like gonorrhea, chlamydia, and syphilis.

—ASHA Staff, Medical Review by H. Hunter Handsfield, MD