Herpes simplex virus type 2 (HSV2) is one of two types of the herpes virus and is rarely transmitted orally. However, that doesn’t mean it’s impossible. People with compromised immune systems in particular may be at risk.

HSV2 is a sexually transmitted virus that causes sores and blisters known as herpes lesions. In order to be infected with HSV2, there has to be skin-to-skin contact between an infected person and a partner. HSV2 is not transmitted through semen.

Once HSV2 enters the body, it travels through the nervous system to the spinal nerves, where it typically comes to rest in the sacral ganglia, a cluster of nerve tissue located near the base of the spine. After the initial infection, HSV2 lies dormant in your nerves. When it becomes activated, a process known as viral shedding occurs. Viral shedding is when the virus replicates. Viral shedding may cause a herpes outbreak and symptoms such as herpes lesions. These usually occur in the genitals or rectum. However, it’s also possible for the virus to be activated and for no visible symptoms to occur.

HSV2 can be asymptomatic, which means it causes no apparent symptoms. That’s why it’s important to use protection during sexual activity and to get tested regularly by a doctor if you are sexually active. You can still transmit the virus to a partner even if you don’t have any apparent symptoms.

In order for HSV2 to be transmitted, there has to be contact between a contagious area on an infected person and breaks in the skin or mucous membranes of their partner. A mucous membrane is the thin layer of skin that covers the inside of your body and produces mucous to protect it. Contagious areas for HSV2 include any active herpes lesions, mucous membranes, or genital or oral secretions.

Because it typically lives in nerves near the base of your spine, HSV2 is typically contracted during vaginal or anal sex, leading to genital herpes. This can happen if herpes sores or unnoticeable, microscopic viral shedding come into direct contact with tiny rips in tears or mucous membranes. The vagina and vulva are particularly vulnerable to HSV2 transmission.

However, in some rare cases, HSV2 has been known to cause oral herpes. The inside of the mouth is also lined with mucous membranes. If the virus comes into contact with these mucous membranes during oral sex, it can pass through them and enter your nervous system, where it can establish dormancy in nerve endings located near the ear. This can lead to oral herpes or herpes esophagitis.

When this happens, the person who is infected with HSV2 can also transmit the virus to their partner by giving oral sex, causing genital herpes. The virus can also be transmitted if a person infected with genital herpes receives oral sex, causing oral herpes in their partner. People with compromised immune systems, such as those undergoing chemotherapy, may be more susceptible to oral transmission.

The other commonly transmitted strain of the herpes simplex virus, HSV1, typically results in oral herpes, or cold sores around the mouth. This form of HSV is more readily transmitted via oral contact, such as kissing, than through genital contact. HSV1 can be transmitted through both giving and receiving oral sex. It can cause both mouth and genital sores. You can also get HSV1 through vaginal and anal intercourse, and through the use of sex toys.

Unlike HSV2, which usually lies dormant between outbreaks at the base of the spine, HSV1’s latency periods are typically spent in nerve endings near the ear. That is why it is more likely to cause oral herpes than genital herpes.

HSV1 and HSV2 are genetically similar to each other. For this reason, having one form of the virus sometimes reduces risk of contracting the other form. This is because your body actively produces antibodies to fight the virus once you have it. However, it is possible to contract both forms.

HSV1 and HSV2 can both have no symptoms or very mild symptoms that you might not notice. Not having symptoms does not mean you do not have the virus.

If you do have symptoms of HSV1, they may include:

  • a tingling sensation, itching, or pain, anywhere in the genital area or around the mouth
  • one or more small, white blisters that may become oozy, or bloody
  • one or more small, red bumps or irritated-looking skin

It is important to see a doctor if you suspect you have contracted HSV1 or HSV2. There is no cure for herpes, but antiviral medications can help reduce the number and severity of your outbreaks.

HSV2 can often be prevented with some proactive strategies. These include:

Prevention tips

  • Always use a condom during any type of sexual activity.
  • Avoid having sex during herpes outbreaks, but be aware that people with herpes may have no symptoms and still transmit the virus.
  • Maintain a mutually monogamous relationship with an infection-free person.
  • Communicate with your sexual partner or partners if you have HSV, and ask if they have it themselves.
  • Abstaining from all forms of sexual activity or reducing the number of sexual partners you have also reduces risk.