Is a Herpes Vaccine Currently In the Works?

Herpes simplex viruses (HSV) are part of a larger family of herpesviruses. They’re very common — affecting over 3 billion people worldwide. And they can cause painful sores in or around the mouth or genitals. Unfortunately, there’s no cure for HSV infections, and people need to manage their outbreaks with medications. Several companies have developed and tested HSV vaccines. But so far, they have not brought any of these products to market.

Yet companies are still trying to figure out how to prevent these infections through vaccination — and with good reason. Research suggests that an HSV vaccine for the virus that commonly causes genital herpes could prevent as many as 350,000 new infections every year.

There are several HSV vaccine candidates in the pipeline. The hope is that they’ll show promise where previous prospects have fallen short. Here, we’ll discuss new and ongoing research in this area and if we can expect a vaccine to be available in the near future.

What is the herpes simplex virus (HSV)?

HSV is a virus that can cause painful ulcers in your mouth (cold sores) or on your genitals. There are two main herpes simplex viruses — HSV-1 and HSV-2. HSV-1 infections most commonly affect your mouth, but they may also result in sores on your genitals. HSV-2, on the other hand, primarily affects your genitals.

Once you’ve been infected with HSV, the virus stays in your body. This can cause sores or blisters to appear periodically (called an outbreak). In rare cases, it can cause life-threatening infections such as meningitis and encephalitis.

When you think of herpesviruses, HSV is likely what comes to mind. But both types of HSV are actually part of a larger family of herpesviruses, including:

• Varicella-zoster virus (causes chickenpox and shingles)

• Epstein-Barr virus (causes mononucleosis)

• Cytomegalovirus

Is there a cure for herpes?

Unfortunately, there’s no cure for herpes at this time. However, researchers are hoping that gene therapy could open the door for a future herpes cure. So far, results from animal studies have been promising.

Currently, HSV infections are managed with prescription antiviral medications, such as Valtrex (valacyclovir) or Zovirax (acyclovir). These medications can help resolve blisters when they appear. And some people take them daily to prevent outbreaks.

But available medications don’t work well for everyone. And condoms may not cover all areas where genital blisters appear. This can make it difficult when trying to avoid transmitting the infection to your partner. The shortcomings of current treatment and prevention options has prompted research into whether a vaccine for these viruses is possible.

Why is creating an HSV vaccine so difficult?

When scientists make vaccines, they target the part of your immune system that recognizes an invader — like a virus or bacteria — in your body. The vaccine then teaches your body how to kill the invader before it makes you sick.

Even though we have vaccines for other illnesses caused by herpesviruses, such as chickenpox and shingles, HSV does a better job of evading the immune system.

What makes HSV so tricky is that it can live in your body undetected. This means your immune system doesn’t react to it right away. Since the immune system doesn’t react to HSV right away, it makes creating an effective vaccine more difficult. 

Good to know: Early HSV vaccine studies in animals had good results. But when these vaccines were studied in humans, they didn’t work as well. So pharmaceutical companies have had to restart their research attempts or have stopped their trials completely.

Are there any herpes vaccines currently being studied for HSV?

Yes, researchers are currently testing vaccines to target both HSV-1 and HSV-2 in humans. Most are being developed for HSV-2. But since the viruses are so similar, an HSV-2 vaccine would also likely work to prevent or treat HSV-1, too.

There are two types of HSV vaccines being studied:

• Treatment vaccines: Also known as therapeutic vaccines, these vaccines would benefit people who’ve already been infected with HSV. They could improve symptoms, help blisters heal faster, and lower the risk of spreading the virus to other people.

• Preventative vaccines: Also known as prophylactic vaccines, these vaccines would benefit people who haven’t been exposed to HSV. They would train your immune system to prevent an HSV infection if you were exposed to the virus in the future.

Just as with any vaccine, all HSV vaccines will need to go through three types of clinical trials — phase 1, 2, and 3 trials — before being approved by the FDA. This to make sure that they’re safe and work well for humans. This process typically takes several years. So it will likely be some time before we see an HSV vaccine come to market. Here are a few HSV vaccine candidates being studied right now.

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Written by:

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP, has over a decade of experience as a pharmacist, professor, and researcher. She currently practices as a clinical pharmacist at Buffalo General Medical Center.

Edited by:

Sheila McAdoo, PharmD

Sheila McAdoo, PharmD, is a licensed pharmacist in Virginia and New York. She has worked in the pharmacy industry for 14 years.

Reviewed by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

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