Not every person with a herpes infection actually experiences breakouts of cold sores throughout his or her lifetime or even after initially becoming infected. How often someone has a herpes cold sore outbreak, how severe the outbreaks are, how contagious someone is after infection and how long the sores take to heal all depend on someone’s individual immune response.
When herpes flares up again, it is called a "recurrence" or "outbreak." Herpes does not always recur, and if it does recur, the timing and severity are different from person to person. Some people rarely have recurrences. Others have them often. Herpes is most likely to recur in the first year after infection. Recurrences may be more frequent for people with weakened immune systems.

In all cases, HSV is never removed from the body by the immune system. Following a primary infection, the virus enters the nerves at the site of primary infection, migrates to the cell body of the neuron, and becomes latent in the ganglion.[14] As a result of primary infection, the body produces antibodies to the particular type of HSV involved, preventing a subsequent infection of that type at a different site. In HSV-1-infected individuals, seroconversion after an oral infection prevents additional HSV-1 infections such as whitlow, genital herpes, and herpes of the eye. Prior HSV-1 seroconversion seems to reduce the symptoms of a later HSV-2 infection, although HSV-2 can still be contracted.
Herpes antiviral therapy began in the early 1960s with the experimental use of medications that interfered with viral replication called deoxyribonucleic acid (DNA) inhibitors. The original use was against normally fatal or debilitating illnesses such as adult encephalitis,[92] keratitis,[93] in immunocompromised (transplant) patients,[94] or disseminated herpes zoster.[95] The original compounds used were 5-iodo-2'-deoxyuridine, AKA idoxuridine, IUdR, or(IDU) and 1-β-D-arabinofuranosylcytosine or ara-C,[96] later marketed under the name cytosar or cytarabine. The usage expanded to include topical treatment of herpes simplex,[97] zoster, and varicella.[98] Some trials combined different antivirals with differing results.[92] The introduction of 9-β-D-arabinofuranosyladenine, (ara-A or vidarabine), considerably less toxic than ara-C, in the mid-1970s, heralded the way for the beginning of regular neonatal antiviral treatment. Vidarabine was the first systemically administered antiviral medication with activity against HSV for which therapeutic efficacy outweighed toxicity for the management of life-threatening HSV disease. Intravenous vidarabine was licensed for use by the U.S. Food and Drug Administration in 1977. Other experimental antivirals of that period included: heparin,[99] trifluorothymidine (TFT),[100] Ribivarin,[101] interferon,[102] Virazole,[103] and 5-methoxymethyl-2'-deoxyuridine (MMUdR).[104] The introduction of 9-(2-hydroxyethoxymethyl)guanine, AKA aciclovir, in the late 1970s[105] raised antiviral treatment another notch and led to vidarabine vs. aciclovir trials in the late 1980s.[106] The lower toxicity and ease of administration over vidarabine has led to aciclovir becoming the drug of choice for herpes treatment after it was licensed by the FDA in 1998.[107] Another advantage in the treatment of neonatal herpes included greater reductions in mortality and morbidity with increased dosages, which did not occur when compared with increased dosages of vidarabine.[107] However, aciclovir seems to inhibit antibody response, and newborns on aciclovir antiviral treatment experienced a slower rise in antibody titer than those on vidarabine.[107]

Herpes viruses typically infect the oral or genital mucosa. When herpes affects the mouth, it causes the typical "cold sores," which are painful sores or blisters that form on the lips, mouth, or gums. Prior to the development of the blisters, there may be a prodrome (early symptoms indicating onset of a particular disease) consisting of an itching, burning, or tingling sensation in the affected area. The virus remains dormant in the nervous system throughout life, and this is the reason that cold sores often recur in the same location.
Worldwide rates of either HSV-1 and/or HSV-2 are between 60 and 95% in adults.[4] HSV-1 is more common than HSV-2, with rates of both increasing as people age.[4] HSV-1 rates are between 70% and 80% in populations of low socioeconomic status and 40% to 60% in populations of improved socioeconomic status.[4] An estimated 536 million people or 16% of the population worldwide were infected with HSV-2 as of 2003 with greater rates among women and in those in the developing world.[10] Rates of infection are determined by the presence of antibodies against either viral species.[81]
Research has gone into vaccines for both prevention and treatment of herpes infections. Unsuccessful clinical trials have been conducted for some glycoprotein subunit vaccines.[citation needed] As of 2017, the future pipeline includes several promising replication-incompetent vaccine proposals while two replication-competent (live-attenuated) HSV vaccine are undergoing human testing.[citation needed]
“Someone having HSV doesn't mean that they were reckless or irresponsible with their sex life,” says Sara, age 30. “I used condoms with all my partners, and I still caught it.” For Jamie, who contracted herpes from her husband three years into their monogamous relationship, he was her first and only sexual partner. And she says that he contracted it from one of his very first sexual encounters. No matter how and why someone contracted the virus, it doesn't erase their humanity and right to respect.
With the first outbreak of herpes virus infection, an individual may also experience nonspecific flu-like symptoms like fever, swollen lymph nodes, headache, and muscle aches. It is also possible to have herpes virus infection without having any symptoms or signs, or having signs and symptoms that are so mild that the infection is mistaken for another condition.
Some people experience very mild genital herpes symptoms or no symptoms at all. Frequently, people infected with the virus don't even know they have it. However, when it causes symptoms, it can be described as extremely painful. This is especially true for the first outbreak, which is often the worst. Outbreaks are described as aches or pains in or around the genital area or burning, pain, or difficulty urinating. Some people experience discharge from the vagina or penis.
The herpes simplex virus is probably the most well-known virus of the herpes family, and it is just as contagious. Herpes simplex infects epithelial cells and remains latent in neurons. HSV-1 causes recurrent oropharyngeal lesions, commonly known as “fever blisters" or "cold sores.” It is also the primary cause of sporadic encephalitis (inflammation of the brain), gingivostomatitis (inflammation of the gums and mucous lining of the mouth), and keratoconjunctivitis (severe dryness of the eye that involves the cornea) and dendritic corneal ulcers (also called HSV keratitis) in which the cornea becomes affected by herpetic lesions that look like the dendrites of neurons in the brain.

Human herpes virus 8 (HHV8) was recently discovered in the tumours called Kaposi's Sarcoma (KS). These tumours are found in people with AIDS and are otherwise very rare. KS forms purplish tumours in the skin and other tissues of some people with AIDS. It is very difficult to treat with medication. HHV8 may also cause other cancers, including certain lymphomas (lymph node cancers) associated with AIDS. The fact that these cancers are caused by a virus may explain why they tend to occur in people with AIDS when their immune systems begin to fail. The discovery also provides new hope that specific treatments for these tumours will be developed that target the virus.
Herpes is transmitted via skin-to-skin contact, not through blood or saliva. Cullins explains that someone with HSV can be shedding the herpes virus without having an outbreak (known as asymptomatic virus shedding), and infect somebody that way. Suppressive antiviral medications, like acyclovir or valacyclovir, inhibit HSV replication, which decreases shedding but does not completely eliminate it, says Johnston.
According to a study in the New England Journal of Medicine, more than 30% of pregnant women in the United States have genital HSV. During pregnancy, people are immunocompromised so that their body doesn’t fight the fetus as a foreign invader. And when a person’s immune system is weakened, they are more likely to have herpes outbreaks. According to Cullins, “Pregnancy is the time period when [a provider] really wants to know whether or not the person has had herpes in the past,” so they can protect the pregnant person and their infant from a herpes infection.