You may have heard about something called HIV reinfection or superinfection. Even though you are both living with HIV, you and your partner may have different strains or subtypes of HIV. There have been a few cases of a person living with HIV getting a different strain of HIV that is resistant to certain medications through sex.
HIV reinfection doesn’t happen frequently. When it does, the person getting another strain of HIV has usually been diagnosed with HIV within the last four years and isn’t taking HIV treatment. Reinfection does not cause serious health problems for most people living with HIV.
Also, once you and your partner have both had an undetectable viral load for six months, HIV is unable to be passed on through sex. If you both continue to take your HIV treatment and remain undetectable, you can have sex without a condom without any worries about passing your strain of HIV to your partner, or your partner passing their strain of HIV to you.
If you or your partner’s viral load is not undetectable, condoms are an option if you are concerned about HIV reinfection.