When you hear the word “herpes,” what do you think of? For most people, herpes is associated with the HSV-1 and HSV-2 herpes simplex viruses, which are the two most commonly occurring types of herpes.
But did you know that, in total, there are actually eight different types of herpes that can affect humans, ranging from the relatively common HSV-1, to recurrent viruses like HHV-3 (shingles), HHV-4 and recently observed forms of the virus, such as HHV-6, 7 and 8?
And of these, one type of herpesvirus (HHV-6), can be divided into two separate viruses. There are over 100 forms of herpes that can affect animals, although few of the viruses are of concern for humans.
Below, we’ve listed all eight types of the herpesvirus that can infect humans, along with a short description of how each type affects the body, infection statistics and the treatment options that are currently available.
Herpes simplex virus 1, or HSV-1, is the most common type of herpesvirus. Around 65 percent of all people aged 14-49 are infected with HSV-1, making it one of the most common viral infections in the world.
HSV-1 can affect the mouth and lips (oral herpes) or genitals (genital herpes). The virus causes outbreaks of herpes sores on the mouth or genitals. Many people with HSV-1 are asymptomatic, meaning they never experience any symptoms even after they’re infected with the virus. It also means that HSV-1 transmission is very common, if you're not careful (And even if you are).
Like other forms of herpesvirus, HSV-1 spreads through direct contact. The most common methods of spreading the virus are kissing and oral sex. HSV-1 is treatable using antiviral medications such as valacyclovir.
Herpes simplex virus, of HSV-2, is the second most common type of herpesvirus. Like HSV-1, it is highly contagious and spreads through direct contact. About 11 percent of people aged 14 to 49 are infected with HSV-2, although many never experience any symptoms.
HSV-2 usually causes genital herpes. It’s typically spread through sexual intercourse and tends to affect women more than men. In rare cases, HSV-2 can spread from the genitals to the mouth to cause oral herpes.
Like HSV-1, HSV-2 has no known cure but can be treated using antiviral medications such as valacyclovir.
Human herpesvirus 3, or HHV-3, is a type of herpesvirus that causes chickenpox and shingles.
HHV-3 is also known as the varicella-zoster virus. It’s an extremely common virus that typically occurs during childhood as chickenpox. The virus typically causes painful, unpleasant lesions that can affect the entire body.
When HHV-3 reoccurs as shingles, it can cause painful, itchy lesions to develop in a band-like pattern across the body. Shingles is an extremely unpleasant infection that can result in lasting, long term pain that persists over several months.
Vaccines for HHV-3 have been available since the 1970s, with the first approved vaccines in the United States available from 1995 to the public. They go by various names including Varivax® and ProQuad® (which is a combination vaccine for measles, mumps, rubella and chickenpox) for children, and Shingrix® and Zostavax® for adults 50 years of age and older.
Human herpesvirus 4, or HHV-4, is an infectious virus that’s often called the Epstein-Barr virus.
HHV-4 is most commonly associated with infectious mononucleosis, or mono—a common virus that most people get infected with at childhood, but whose symptoms mostly affect young people and adults. Mono spreads through saliva and is known by many people as the “kissing virus.”
The symptoms of HHV-4 typically pass on their own over the course of two to four weeks, with antiviral medications such as valacyclovir rarely necessary. However, in some cases, a healthcare professional may recommend medication to treat mono if initial healing is slow or symptoms are severe.
Human herpesvirus 5, or HHV-5, is widely known as the cytomegalovirus (CMV). Like the other forms of herpesvirus, CMV is a common virus that can affect people of all sexes and ages. As with other viruses of this type, CMV is a lifelong infection without a known cure.
CMV is extremely common worldwide, affecting an estimated 50 percent of all adults by age 40.
In infants, CMV typically spreads during birth. The virus can also spread to infants via breast milk. Other common transmission methods include sharing toys and/or items that come into contact with the mouth, such as dining utensils.
After catching CMV, some people experience flu-like symptoms, although many people with the virus are asymptomatic. The virus is typically asymptomatic, but can cause significant problems for people with compromised immune systems.
Treatment for CMV can vary based on symptoms and a person’s immune system, ranging from bed rest to antiviral medications in people with severe symptoms from the virus.
Human herpesvirus 6, or HHV-6, is a form of the herpesvirus that, according to the CDC, causes “roseola infantum or exanthem subitum, a common childhood disease that resolves spontaneously.” While some cases of HHV-6 are asymptomatic, symptoms of the virus include fever, rash, ear infections, respiratory and gastrointestinal issues and even seizures during a primary outbreak.
HHV-6 most commonly affects people during childhood as HHV-6B. HHV-6 is very common in young children, accounting for approximately 20 percent of all fever emergency room visits by young children. The virus is also common in people that receive organ transplants.
Like other forms of herpesvirus, HHV-6 is very common. Although the virus was only discovered in the 1980s, a reported 64 percent to 83 percent of children in the United States catch the virus at some point in early childhood.
HHV-6 infects the salivary glands, meaning that both the HHV-6A and HHV-6B forms of HHV-6 spread through saliva. As of 2018, there are no medications that treat HHV-6, although antiviral medications used to treat CMV are currently being studied as potential treatments.
Human herpesvirus 7, or HHV-7, is another common form of herpesvirus that’s estimated to be found in the majority of humans. The virus was first identified in 1990 and is believed to be closely related to HHV-6 in humans.
Symptoms of HHV-7 include roseola, fever, diarrhea, vomiting and seizures, as well as flu-like symptoms. Many people infected with the virus experience no symptoms.
Like HHV-6, HHV-7 is extremely common. More than 95 percent of US adults are believed to have the virus, with the majority of people becoming infected before six years of age. Like HHV-6, there is currently no known treatment for HHV-7.
Human herpesvirus 8, or HHV-8, is the most recently discovered form of the human herpesviruses. The virus was recently identified in tumors of Kaposi sarcoma, a cancer that can cause lesions to develop on the skin, lymph nodes and internal organs of people with AIDS.
HHV-8 is also known as Kaposi's sarcoma-associated herpesvirus. The virus is fairly common in people with HIV/AIDS, with as many as 35 percent of AIDS patients believed to be infected. HHV-8 is also found in patients that have received organ transplants.
As with other forms of herpes, there is no cure for HHV-8. However, the virus is treatable using highly active antiretroviral therapy (HAART)—a combination of antiretroviral drugs to improve immune system function and prevent opportunistic infections from developing.
Interested in learning more about how herpes is treated? From common infections like HSV-1 and HSV-2 to the varicella-zoster virus, most types of herpes are treated through antiviral medications such as valacyclovir. Think you might have herpes? Don't hesitate to call your healthcare provider about getting an HSV test.
Our Valacyclovir 101 guide covers all there is to know about this common and highly effective antiviral drug, from dosage guidelines and brand names to side effects, mechanism of action, interactions and more.