Short answer
If you both have confirmed HSV-2 at the same site, transmission of that virus between you is no longer the live question; small strain-typing studies find reinfection with a second strain uncommon rather than impossible. If your types or sites differ, each of you can still acquire the one you lack, and prior HSV-1 does not block HSV-2. Confirm both diagnoses before you rely on a match, and keep condoms for the other STIs.
Checked September 15, 2026 · Sources: CDC, WHO, Annals of Internal Medicine, NEJM, Journal of Infectious Diseases, listed at the end · This site is run by an employee of the company that owns PositiveSingles. Why that matters
The short answer, by pairing
Whether two partners who both have herpes still need a condom for that virus turns on whether your types and sites actually match. About a dozen of the 393 questions we read in the PositiveSingles anonymous board on September 15, 2026 were a version of this.
| Your pairing | Transmission of that virus between you | What is still open |
|---|---|---|
| Same type, same site (both genital HSV-2, or both genital HSV-1) | No longer the live question. Reinfection with a second strain looks uncommon in adults with a working immune system, in small studies. | Other STIs, outbreaks and comfort, and whether both diagnoses were confirmed. |
| Same type, different site (one oral HSV-1, one genital HSV-1) | The WHO states people with HSV-1 are not at risk of HSV-1 reinfection; the HSV-1 typing study below found a different strain in 2 of 13 genital patients. Oral-genital couples are not well studied. | The row above, plus the cold-sore rule: no kissing or oral sex while a sore or its warning tingle is present (see the kissing guide). |
| Different types (one HSV-1, one HSV-2) | Each of you can still acquire the type you lack. Prior HSV-1 does not block HSV-2. | The same precautions as any couple where one partner lacks a type: barriers, no contact during symptoms, and a conversation about daily antivirals. |
Match the details before you relax
"I have herpes" and "I have herpes" are not automatically the same thing. Before you treat your diagnoses as matched, line up three facts for each of you: the type, HSV-1 or HSV-2, which you may never have been told; the site, oral or genital, which a profile label such as HSV-1 (G) carries and the label guide decodes; and how it was confirmed, since a typed swab from a sore is the reliable route and a single low-index blood test is where matched diagnoses go wrong.
The CDC's treatment guidelines (reviewed September 21, 2022) warn that the common HSV-2 antibody test is often falsely positive at low index values (1.1 to 3.0), citing one study with a specificity of 39.8% for index values of 1.1 to 2.9, and recommend a confirmatory test by a second method before interpreting the result. If either of you was diagnosed from a blood test alone with a low index value and no symptoms, "we both have HSV-2" may be one true diagnosis and one false positive. That is the couple who most needs the confirmatory test, because their decisions about protection depend on it.
Same type, same site: what the reinfection studies found
The worry here is reinfection: could your partner's strain of HSV-2 give you a second infection on top of your own? The evidence is a handful of small, mostly old strain-typing studies.
| Study | Who | What was found |
|---|---|---|
| Schmidt, Fife, Corey, 1984 | Patients with symptomatic recurrent genital herpes | Concluded, in its own title, that reinfection is an uncommon occurrence in such patients. |
| Lakeman, Nahmias, Whitley, 1986 | 15 patients with recurrent genital HSV-2; 35 sequential isolates | No patient showed reinfection with a genetically distinct HSV-2 strain. |
| Roest and colleagues, 2004 | 13 patients with recurrent genital HSV-1 | Same genotype in 11 of 13; 2 showed a different strain, so genital HSV-1 reinfection can happen. |
| Roest and colleagues, 2006 | Patients with recurrent genital HSV-2, with and without HIV | A different HSV-2 genotype in 11 of 11 HIV-positive patients and 1 of 8 HIV-negative patients. |
Read together: in adults with a working immune system, reinfection with a second strain of the type you already carry is uncommon but has been documented, and HIV changes that picture substantially. That is why the table at the top says "no longer the live question" rather than "zero". If either of you is immunocompromised, ask a clinician.
Different types: prior HSV-1 does not block HSV-2
The pairing easiest to mistake for matched is one partner with genital HSV-1 and the other with genital HSV-2. These are different viruses, and the CDC states that people with HSV-1 antibodies remain at risk of acquiring HSV-2 regardless of where the HSV-1 infection is. The WHO fact sheet (dated May 30, 2025) says the same: people who already have HSV-1 are not at risk of HSV-1 reinfection, but are still at risk of acquiring HSV-2. Whether prior HSV-1 at least lowers the odds is where two cohorts disagree, so both are shown with their populations.
| Study | Population and follow-up | Result |
|---|---|---|
| Mertz and colleagues, 1992 | 144 heterosexual couples, one partner with recurrent genital HSV and the other susceptible; median 334 days | HSV-2 acquisition was 31.8% a year in women with no HSV antibodies and 9.1% in women with HSV-1 antibodies at entry. Only 14 couples (9.7%) transmitted at all, so the comparison rests on few events; in 9 of the 13 couples with detailed histories, the source partner was reported asymptomatic at the time. |
| Langenberg and colleagues, 1999 | 2,393 sexually active HSV-2-seronegative participants in an HSV vaccine study (1,508 with HSV-1, 885 without); new HSV-2 at 5.1 per 100 person-years | 155 new HSV-2 infections. Prior HSV-1 did not reduce the rate of HSV-2 infection, but made a silent infection 2.6 times more likely than a symptomatic one. Only 57 of the 155 (37%) were symptomatic. |
Prior HSV-1 may soften a new HSV-2 infection, and might lower the odds in some groups, but it does not prevent it. A couple with different types should treat themselves like any couple where one partner lacks a type. The daily-valacyclovir result in the transmission guide comes from HSV-2 source partners and describes the direction in which the HSV-2 partner could pass HSV-2. For genital HSV-1 passing the other way, the CDC states suppressive therapy to prevent HSV-1 transmission has not been studied, and that genital HSV-1 sheds and recurs less than HSV-2. Barriers and avoiding contact during symptoms apply both ways.
Condoms and daily antivirals when you both have it
Here the evidence has a hole shaped exactly like the question. The transmission-reduction claim for daily valacyclovir comes from discordant couples, one partner with HSV-2 and one without, followed 8 months; the product label (revised February 2026) says efficacy beyond that period has not been established and that safer-sex practices should be used alongside suppressive therapy. There is no equivalent trial in couples who both have HSV-2, and what such a trial would measure, reinfection with a second strain, the studies above found uncommon rather than absent. So for the virus you share, keep condoms for the other STIs and comfort, not as a barrier against a reinfection the evidence does not support.
What is still open once the match is confirmed
Other STIs: a matched herpes diagnosis says nothing about chlamydia, syphilis, HIV, or HPV, each of which needs its own test, and the CDC says all people with genital herpes should be tested for HIV because HSV-2 raises the risk of acquiring HIV twofold to threefold. Who gave it to whom usually cannot be answered, because most new infections cause no symptoms at the time (98 of the 155 in the 1999 cohort) and antibody tests cannot date an infection; dating after a diagnosis has more on letting that go. Immune status matters, because HIV changed the reinfection picture above. And each other's outbreak history, triggers, and medication will come up once you share a bed, even though none of it changes transmission between you.
Sources
- CDC STI Treatment Guidelines, 2021: Genital Herpes. Partner evaluation, type-specific serology, the low-index caveat, and HIV testing. Page reviewed September 21, 2022.
- WHO fact sheet: herpes simplex virus. Dated May 30, 2025: HSV-1 carriers remain at risk of acquiring HSV-2.
- Mertz GJ et al. Ann Intern Med. 1992;116(3):197-202. 144 couples; 31.8% vs 9.1% annual acquisition by prior HSV-1 status.
- Langenberg AG et al. N Engl J Med. 1999;341(19):1432-8. 2,393 people; prior HSV-1 did not cut the HSV-2 rate but made new infections more often silent.
- Schmidt OW, Fife KH, Corey L. J Infect Dis. 1984;149(4):645-6. Reinfection uncommon in symptomatic recurrent genital herpes.
- Lakeman AD, Nahmias AJ, Whitley RJ. Sex Transm Dis. 1986;13(2):61-6. 15 patients, 35 isolates, no distinct reinfecting strain.
- Roest RW et al. J Med Virol. 2004;73(4):601-4. 2 of 13 genital HSV-1 patients showed a different strain.
- Roest RW et al. J Infect Dis. 2006;194(8):1115-8. Different HSV-2 genotype in 11 of 11 HIV-positive and 1 of 8 HIV-negative patients.
- Valacyclovir prescribing information, DailyMed. Transmission data from 8-month discordant-couple trials; revised February 2026.