Herpes simplex virus 1 and 2 (HSV-1 and HSV-2), also known as human herpesvirus 1 and 2 (HHV-1 and HHV-2), are two members of the human Herpesviridae family, a set of viruses that produce viral infections in the majority of humans. Both HSV-1 (which produces most cold sores) and HSV-2 (which produces most genital herpes) are very common and contagious. They can be spread when an infected person begins shedding the virus. About 67% of the world population under the age of 50 has HSV-1. In the United States more than one-in-six people have HSV-2.

A scab characteristic of herpetic disease

Although it can be transmitted through any intimate contact, it is one of the most common sexually transmitted infections. Many of those who are infected never develop symptoms. Symptoms, when they occur, may include watery blisters in the skin or mucous membranes of the mouth, lips, nose, or genitals. Lesions heal with a scab characteristic of herpetic disease. Sometimes, the viruses cause very mild or atypical symptoms during outbreaks.

However, they can also cause more troublesome forms of herpes simplex. As neurotropic and neuroinvasive viruses, HSV-1 and -2 persist in the body by hiding from the immune system in the cell bodies of neurons. After the initial or primary infection, some infected people experience sporadic episodes of viral reactivation or outbreaks. In an outbreak, the virus in a nerve cell becomes active and; transported via the neuron’s axon to the skin, where virus replication and shedding occur and cause new sores.

The results from a recent clinical trial led to a label expansion for an adult antiviral for the treatment of herpes simplex virus (HSV). Based on this study’s data, newborn infants up to 3 months of age, who have infections with HSV, can now be treated with Acyclovir. This is important news since newborns can become infected with the herpes virus during pregnancy, labor, delivery or shortly after birth if the mother develops genital herpes near the end of her pregnancy.

For youngest patients

An HSV infection in newborns can cause death or long-term problems, such as blindness and damage to the brain, says the NIH. Manifestations of neonatal HSV generally occur between the 1st and 3rd weeks of life. As an example of post-delivery infection, a previous meta-study reviewed 6 published studies which documented HSV-1 infection in neonatal males after circumcision with direct oral suction. One study described 11 cases in New York City and estimated a statistically significant risk ratio associated with oral suction based on 5 of those cases.
The data that informed this label change came from a study; funded by the National Institutes of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).  Results from these studies provide information on the most appropriate use of these therapies; and may inform an update to the drug’s label by the U.S. Food and Drug Administration.

Perdita Taylor-Zapata said in a press release, “With this label change; healthcare providers have clear guidance on how to use and prescribe this drug for their youngest patients.”NICHD’s BPCA program supports the Pediatric Trials Network (PTN); which studies drugs and therapies commonly prescribed for infants and children but never specifically tested in them. Results from the PTN study; that generated data for Acyclovir’s label change is available online at NICHD’s Data and Specimen Hub.