There are more than 100 known herpesviruses, eight of which infect only humans. Here’s a look at recent stories and research on herpesviruses.
When people think of “herpes,” they tend to think of genital herpes, which is a sexually transmitted disease (STD) caused by two types of viruses, herpes simplex virus type 1 (HSV-1) and HSV-2.
HSV-1 can also cause oral herpes, resulting in cold sores or fever blisters on or around the mouth. Otherwise, there are more than 100 known herpesviruses and eight that infect only humans, including varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, and others. Here’s a look at some recent stories and research on herpesviruses.
Thailand Reports 3 Cases of Monkeypox are Herpes
There has been an unusual outbreak of monkeypox in several countries worldwide. This disease is caused by the monkeypox virus. However, because there are no specific assays available yet for monkeypox, most diagnoses are from clinical symptoms. The Thai Department of Disease Control reported that three cases of suspected monkeypox were actually herpes.
Virios Publishes Data Linking HSV-1 to Common GI Disorders
Virios Therapeutics announced data from a pilot study at the University of Alabama was published in the journal Infection. The data suggest a potential mechanistic tie between active herpes virus infection and functional gastrointestinal disorders (FGID) with or without comorbid fibromyalgia (FM). They also suggested a potential combination therapy for patients with FGIDs and FM.
Tissue biopsies were collected from people with FGID, such as irritable bowel syndrome, as well as comorbid FM; a group with FGID only; and a third control group, without FGID or FM. Neither histological gastritis nor H. pylori infection was associated with FGIDs or FM.
They did, however, find a “marked increase in the presence of actively replicating herpes simplex virus type 1 (HSV-1) in gastric mucosal tissue from the FGID and the FGID and FM patient groups as compared to control patients,” Dr. R. Michael Gendreau, M.D., Ph.D., chief medical officer of Virios, said.
Weaponized Herpesvirus to Treat Cancer
Investigators at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB genetically modified HSV-1 to fight cancer. They deactivated the genes that cause disease, then programmed them to enter cancer cells, multiply and release tumor markers that stimulate the body’s immune system to attack the cancer cells.
“In addition, we activate the immune response with specific proteins that our viruses release when they reproduce,” said Susanne Bailer, Ph.D., who led the research. “The immune system then recognizes the tumor cells and eliminates them. The immune system is the most powerful weapon we have to fight cancer. Using the virus and the released tumor markers, we are aiming to stimulate the immune system in a targeted way so that the body can basically treat itself.”
The results were promising in preclinical assays of non-small cell lung cancer (NSCLC).
HSV and CMV Vaccines on the Horizon
One of the peculiarities of HSV-1 and -2 infections is that most people, at one time or another, have been exposed to the viruses. And once you have an active infection of genital or oral herpes, it often goes into remission but will flare up again when your immune system is under stress.
Cytomegalovirus (CMV) is a type of herpesvirus that infects anywhere from 50% to 85% of adults in the U.S. and more adults everywhere else. And for the most part, it’s no big deal, unless you’re immunosuppressed or pregnant. In which case, the virus can be passed on to the baby, leading to congenital disabilities, including vision and hearing loss, seizures and cognitive and motor impairments. But since so many adults have been exposed to CMV or HSV at one time or another during their life, it’s not always easy to know if the mother’s antibodies are in response to an active infection that could be passed to the child or are from previous exposure.
Moderna is actively developing vaccines for both HSV-1 and -2 as well as CMV using the same mRNA technology used to create the COVID-19 vaccine. The CMV vaccine candidate, mRNA-1647, is currently in Phase III clinical studies. The HSV vaccine, mRNA-1608, is in preclinical development. The company completed enrollment of the Phase II study of mRNA-1647 in March 2020, with positive safety and efficacy data. The HSV vaccine was part of the company’s announced pipeline expansion in February 2022.
Herpesviruses and Diabetes Risk
A study published earlier this year found an association between HSV-2 and CMV infections and diabetes. The research goal was to look at associations between latent herpesvirus infections and the development of prediabetes, which often precedes type 2 diabetes. They tracked seven herpesvirus and diabetes biomarkers over several years.
They found that 360 participants developed markers of prediabetes over the almost seven-year follow-up, and of those, HSV-2 and CMV were frequently detected. HSV-2 had the strongest link, with people infected being 59% more likely to develop prediabetes, with CMV infections tied to a 33% increase likelihood of developing prediabetes.
The authors caution that this is a preliminary observational association and that diabetes has many other risk factors, including cholesterol and obesity, that play a much greater role than herpesvirus in the likelihood of developing prediabetes. It’s also not known if there’s a causal link. The research was published in Diabetologia.
EBV and HSV Tied to Multiple Sclerosis (MS)
Another study this year found an association between HSVs and Epstein-Barr virus (EBV) and multiple sclerosis (MS). When they go into a latent phase, these viruses tend to move along parts of the central nervous system. Their ability to reactivate after acute infection allows the viruses to form long-term associations with neurons, astrocytes, and oligodendrocytes, which they believe might be causes or linked to exacerbated neuroinflammation seen in MS patients. Earlier research in this area was mixed. The most recent study tried to tie the prevalence of herpesvirus seropositive in MS patients with neurologic controls without MS. The data suggested that EBV infection was linked to MS, but HSV-1 and -2 were not.
