"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 sterilizing immunity, meaning there was no trace of herpes infection or disease after the exposure. The one remaining mouse developed dormant infection without any prior genital disease. 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."

"Building on the approaches of many 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 virus's entry as the mode to attack the virus."

Please see full article : https://www.pennmedicine.org/news/news-releases/2019/september/new-penn-developed-vaccine-prevents-herpes-in-mice-guinea-pigs