Genital herpes is the most prevalent sexually transmitted disease in the world. More than 1 billion people host the herpes simplex virus 2 (HSV-2), and there is currently no immunization or cure for the infection. Despite its prevalence, the majority of the infected population is unaware that they carry the virus. Current methods to treat symptoms consist of drugs such as Famciclovir and Valacyclovir, which shorten the outbreaks.
Although these solutions help reduce the manifestation of symptoms, they cannot totally prevent them nor new infections. For many years, scientists have been searching for viable ways to immunize people against this pandemic, but their efforts have been unsuccessful until only very recently. A team of researchers working at the University of Pennsylvania may have created the first vaccine that can successfully neutralize the genital herpes virus.
Targeting three glycoproteins
The new vaccine targets three glycoproteins that are critical to the virus infection mechanism: gC2, gD2, gE2. This contrasts with previous efforts that targeted only gD2. According to Harvey M. Friedman, professor of Infectious Diseases at the University of Pennsylvania who helped develop the vaccine, this enables the immune system to fight HSV-2 more effectively because it weakens not only the virus ability to infect host cells but also its fight-back mechanisms. The glycoproteins gC2 and gE2 hinder the immune system's ability to respond to the infection, and gD2 is implicated in the mechanism of cell invasion.
In trials with rhesus macaques and guinea pigs, the trivalent vaccine proved to be a potent immunizer against HSV-2. It helped the immune systems of these animals produce antibodies that successfully neutralized the three glycoproteins, rendering the virus incapable of causing symptoms and spreading. Upon analyzing the animals' genital secretions, scientists verified that the genetic footprint of HSV-2 had been dramatically decreased thanks to the new immunization.
Genital herpes immunization on the horizon
Rhesus macaques have already been instrumental in the development of vaccines and drugs for diseases such as polio, rabies and HIV/AIDS because their immune system is relatively similar to that of humans. Dr. Sita Awasthi, lead author of the study, says that if clinical trials on humans are equally successful, the new vaccine could prevent genital herpes from spreading worldwide and also reduce the number of new HIV infections. The greatest impact would be in Africa, the most affected region. Researchers are already in talks with pharmaceutical companies to start the first human trials before the vaccine is, hopefully, unleashed to the general public.