Researchers discover vaccine to treat herpes

Researchers have discovered a new vaccine which is proving to be effective in combating herpes virus.

In the study, researchers delivered the Penn-developed vaccine to 64 mice and then exposed them to genital herpes. After 28 days, 63 of the mice were found to have sterilising immunity, meaning there was no trace of herpes infection or disease after the exposure.

Similarly, 10 guinea pigs, which have responses to herpes infections that more closely resemble that of humans, were also given the vaccine and exposed to the virus.

No animal developed genital lesions and only two showed any evidence that they became infected, but the infection was not in a form that animals could transmit the virus, reported the study published in the journal, 'Science Immunology'.

"We're extremely encouraged by the substantial immunising effect our vaccine had in these animal models," said the study's principal investigator Harvey Friedman, MD, a professor of Infectious Diseases.

"Based on these results, it is our hope that this vaccine could be translated into human studies to test both the safety and efficacy of our approach," added Friedman.

Building on the approaches of much cutting-edge cancer and immunotherapy researchers, the Penn team filled their vaccine with specific messenger RNA (mRNA), which can create proteins necessary for a strong immune response.

This vaccine stimulates three types of antibodies: one that blocks the herpes virus from entering cells, and two others that ensure the virus doesn't "turn off" innate immune system protective functions.

This approach differs from other herpes vaccines, which often only rely on blocking the virus's entry as the mode to attack the virus.

Genital herpes also called Herpes simplex virus type 2 or HSV-2 is the most common sexually-transmitted disease. Approximately 14 per cent of Americans ages 14 to 59, and 11 per cent of people in the same age range across the world are infected. HSV-2 may lead to painful sores, which can spread to other areas of the body.

The virus increases one's risk of contracting HIV and infected pregnant women may pass herpes onto their fetus, or more commonly, to their baby during delivery.

"Along with physical symptoms, HSV-2 takes an emotional toll," said Friedman. "People worry over the transmission of the disease, and it can certainly have a negative effect on intimate relationships."

Since herpes is so widespread but also often undetected, as it is only visible during an outbreak, researchers say a successful vaccine would be invaluable to many adults across the world.