In general, talking about sexually transmitted infections (STIs) is kind of a mood-killer. But the word “herpes” in particular invokes a special kind of fear and paranoia. Even though genital herpes is fairly common (roughly one in six Americans has it, according to the Centers for Disease Control & Prevention [CDC]), it’s highly stigmatized, in large part because there is no cure.
But why is there no vaccine or cure for one of the most feared (and common) STIs? And have we gotten any closer to discovering one?
Here’s what we discovered after chatting with experts.
What is herpes?
There are two main types of herpes: oral herpes and genital herpes. Oral is caused by herpes simplex virus 1 (HSV-1), and is the virus that causes cold sores. It is extremely common: in fact, the CDC estimates that roughly 48% of Americans between 14–49 years old have oral herpes. People with oral herpes typically get the virus as children by kissing family members or friends.
By contrast, genital herpes is caused by the herpes simplex virus type 2 (HSV-2), which is typically transmitted via anal, vaginal, or oral sex. HSV-2 can result in an outbreak of blisters on the genitals or rectum, but many people can also be asymptomatic.
Why is there no cure for herpes?
Currently, there is no cure for either HSV-1 or HSV-2, though people with both types of herpes can take antiviral medications like Valtrex to control their symptoms and reduce their risk of transmitting the virus to their partners.
For the past 80 years, however, scientists have been researching possible herpes vaccines. (Note: although “cure” and “vaccine” are sometimes used interchangeably, they are not the same. In the case of herpes, a cure would completely eliminate the herpes virus from your body, while a vaccine would treat or prevent it.)
So far, scientists have tried to develop two types of herpes vaccines: a preventive one, which protects you from getting infected in the first place; and a therapeutic one, which would help manage symptoms in people who already have the disease and reduce the risk of outbreaks better than current antiviral medications on the market. Yet they’ve had little luck.
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The herpes virus is extremely complicated
According to Dr. Anna Wald, the head of Allergy and Infectious Diseases Division at the School of Medicine at the University of Washington, herpes is just one of many sexually transmitted viruses that scientists don’t fully understand.
“We don’t have a cure for a lot of things,” she says, citing HIV and hepatitis as other examples.
As Wald explains it, most viruses attack our cells and attempt to multiply as soon as they enter our bodies. In response, our immune system releases white blood cells and antibodies to neutralize the virus and make it less harmful. Often, our immune systems can clear viruses out of our bodies, meaning we’re no longer infected.
But herpes is more complicated than that, says Wald. Herpes “has figured out how to live in the host despite the immune response,” she explains.
Unlike other viruses, herpes hides in the central nervous system, and our immune system can’t easily access this area of our bodies, Wald says. To make things even more complicated, the virus can lie dormant in our central nervous systems for an extended period of time (this explains why people with herpes may go several months without any flare-ups after an initial outbreak, or never have any symptoms at all).
The fact that our immune systems don’t know how to protect us from herpes makes it extremely tough for scientists to make a preventive vaccine. “It’s very difficult to make a vaccine unless you know what kind of immune response you’re trying to make to protect someone,” Wald says. Unlike other viruses like the human papillomavirus (HPV), for instance, researchers cannot inject part of the herpes virus into our bodies as a vaccine, making them create an antibody that fights back and prevents infection.
As for therapeutic vaccines, they would have to be significantly better than current antiviral medications are at reducing the likelihood of transmission and outbreaks, says Dr. Hunter Hansfield, Professor Emeritus of Medicine, University of Washington Center for AIDS and STDs. Fortunately, current antiviral medications can already reduce the recurrence of outbreaks by about 70 percent, according to American Family Physician.
How close are we to a successful herpes vaccine?
In 2016, it seemed as if we were on the cusp of a herpes vaccine when the bioscience company Genocea announced that it had completed phase 2 clinical trials for a therapeutic vaccine called GEN-003. Research showed that herpes patients were 65 percent less likely to have outbreaks after receiving the vaccine and were 60 percent less likely to transmit the virus to their partners .
But lack of funding killed the project, a company spokesperson explained to MensHealth.com. In September 2017, the company stopped development of GEN-003 because they didn’t have enough money to pay for phase three clinical trials, which would have been required to be approved by the Food and Drug Administration (FDA). The company is now focusing primarily on cancer research.
Will we ever get a herpes vaccine?
Not for a long time, at least: at the moment, there are no clinical trials underway for a herpes vaccine.
Hansfield believes it’s extremely unlikely that researchers could develop a herpes vaccine would be able to totally eliminate the virus from someone’s system.
As for a preventive vaccine, “I would be surprised if there was a HSV vaccine on the market that prevents herpes in under 10 years,” he says.
How to protect yourself from herpes
Aside from not having sex, there is no 100% effective way to prevent herpes. You can reduce the risk of contracting the infection by using a condom, but even a condom is not foolproof, as the virus can be transmitted even if your partner has no visible sores.
That said, if you or your partner has herpes, taking antiviral medications can significantly reduce the chances of transmission.
If you exhibit any of the symptoms of genital herpes, such as cracked, red sores around your genitals or rectum, ask your doctor for a blood test to detect HSV antibodies. Even if you test negative, regular STI screening is important for anyone who is sexually active, and free and low-cost testing resources can be found on the CDC’s website.
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