Herpes is one of the most prevalent viruses in humans, but this may not always be the case. Last week, researchers from The University of Pennsylvania reported their most recent success in plans to develop a herpes vaccine. The goal is for this vaccine to work similarly to that currently used to prevent HPV infections, and thus significantly lower the prevalence of herpes infections in future populations.
In a study published last week in Science Immunology, results showed that a herpes vaccine candidate was able to deliver herpes immunity in 63 of the 64 mice treated. Similar results were found in guinea pigs. In this case, none of the 10 guinea pigs treated with the vaccine and later exposed to the virus went on to develop genital lesions. Two, however, did develop a dormant version of the virus.
Efforts to create a cure for, or vaccine against, herpes is nothing new, and as explained by study co-author, Dr. Sita Awasthi, scientists have been attempting just this for the better part of a century. What makes this attempt different from previous is that, rather than making a traditional vaccine, the team is creating something known as an mRNA vaccine.
Vaccines work by eliciting an immune response from the body, therefore helping an organism develop a long-term immunity from a pathogen. This is fairly successful in most cases, but not so much for herpes.
The University of Pennsylvania’s mRNA vaccine works by giving the body instructions on how to build the antigen needed to create an immune reaction, rather than introducing the antigen in its final form.
So far, the results are promising and the team hopes to recreate them in humans. However, according to Awasthi, the candidate vaccine still has to follow the regulatory requirements for early phase clinical studies, meaning human trials won’t begin just yet.
“We are expecting to be ready for early phase clinical study within a couple of years,” said Awasthi.
If successful, the vaccine will ideally be used on adolescents to prevent herpes infection before exposure, similar to the HPV vaccine.
The HPV vaccine was introduced in 2006 and in the years since its first use, the vaccine is believed to have contributed to a significant decrease in HPV infections among young female populations. For example, within 10 years of the vaccine’s introduction, HPV prevalence decreased 86 percent among teenage girls and 71 percent in young women, the Center for Disease Control and Prevention report.
If similar numbers are reached for herpes infection rates, the result could be lead to far more than just protecting future generations from an often stigmatizing skin infection.
“One area it [a herpes vaccine] may have benefits beyond herpes infection/STI is that genital herpes is a known risk factor (4 fold increase) for HIV acquisition and transmission,” said Awasthi. “If the vaccine successfully prevents genital herpes infection, it may help reduce HIV acquisition and transmission.”