Herpes Simplex Virus Type 2 – Some People Have Greater Resistance to Herpes Infection

"I'm just starting a new relationship with my boyfriend," Diana writes, "and he has disclosed to me that, although he has never had any symptoms, he knows he is infected with herpes simplex virus type 2(also known as HSV-2). I get cold sores (caused by herpes simplex virus type 1, also known as HSV-1) several times a year, and I take Valtrex to make the outbreaks less frequent. We have been using protection when we have intercourse, but we would like to have oral sex."

Diana's question is common in the modern dating world. Tens of millions of people are infected with herpes simplex 1, which used to be referred to as the "oral" form of herpes, or herpes simplex 2, which used to be referred to as the "genital" form of herpes. Couples often discover that one partner is infected with one strain of the virus and the other partner is infected with the other strain of the virus, and they don't know how much sex they can have safely.

As it turns, quite a lot. But certain reasonable precautions are a must.

The herpes virus is passed skin-to-skin. It's only active a few days out of the year. The first year you are infected with HSV-1, for example, you might pass on the virus if you had sex on any of about 30 days. The first year you are infected with HSV-2, you might be capable of passing on the virus on any of about 60 days. Every year you have the infection, there are fewer and fewer days you are infectious, as your immune system does a better and better job of keeping the virus bottle up in the nerves where it hibernates.

It's absolutely essential not to have contact with blistered skin. Condoms can break or slip, so couples should abstain from intercourse when one has blisters. This is even true if both partners have HSV-2, since there are different strains of the virus that can act like a new infection, starting the cycle of frequent and severe blistering and multiple days of being infectious every year.

The rest of the time, if you already have one form of herpes, it's not likely your partner will give you the other kind of herpes, even if you have unprotected sex, and even if your partner is infectious. That's because either kind of herpes activates your immune defenses against the other. For instance, for partners who avoid sex when blisters are obvious, transmission is possible, but other factors make it less likely:

• If neither of you has any herpesvirus infection, you won't infect each other.
• If both of you have the same kind of herpesvirus in the same location, you should still avoid unprotected kissing or sex when either of you has an outbreak. That's so you want get infected with two different strains of HSV-1 or two different strains of HSV-2.
• If you have oral HSV-1 and you partner does not have herpes at all, you are highly likely to give your partner oral HSV-1, but not as likely to give your partner genital HSV-1 by performing oral sex. That's because HSV-1 doesn't like the genitals and it takes a large amount of the virus to infect the genitals with HSV-1.
• If you have oral HSV-2 and your partner does not have herpes at all, then you are highly likely to give your partner genital HSV-2 during intercourse, but not as likely to give your partner HSV-2 while performing oral sex.
• If you have genital HSV-1 and your partner does not have herpes at all, your partner can catch the disease while performing oral sex on you but not when you perform oral sex on your partner.
• If you have genital HSV-2 and your partner has oral HSV-1, your partner is not likely to catch HSV-2 when giving you oral sex, but can catch HSV-2 during unprotected genital sex.
• If you don't have herpes at all and your partner has oral HSV-1, you aren't likely to get infected genitals while receiving oral sex, because your genitals are not especially sensitive to HSV-1. You can, however, pick up an oral infection with HSV-1 by kissing your partner when he or she is shedding the virus.

There are other potential combinations of infections and sexual positions, but these are the most common. HSV-1 gives you resistance to HSV-2. But the kindest thing you can do for your partner is to take a viral suppressive medication to greatly reduce the chances of transmitting the virus at all.