UF Researchers Test Herpes Vaccine

January 22, 1997

GAINESVILLE, Fla.—University of Florida researchers and their counterparts at medical centers nationwide are testing a vaccine designed to stop the herpes virus dead in its tracks.

More than just a scourge of sexual promiscuity, herpes is a major health hazard for the nation’s children: 1 in 5,000 infants contracts the virus from the mother at birth. And such infections are 15 times more prevalent in day-care centers and places where the likelihood of close contact is greater than average.

“The public thinks of herpes as an alien monster,” said Dr. Peter Reuman, an associate professor of pediatric infectious diseases at UF’s College of Medicine. “The only way we can rid the virus from the human species is to prevent it from infecting people.”

“We can’t say for sure whether it works or not and I can’t promise protection,” Reuman said. “But this vaccine has been shown to have a good immune response, and there is a good chance this will correlate well with protection.”

With that aim, researchers are testing a synthetically engineered vaccine consisting of an artificial protein and other chemicals they hope will trick the body into thinking it has been infected by herpes simplex types 1 and 2, forcing it to create protective immunity.

From the common cold sore to a highly infectious sexually transmitted disease, herpes viruses are difficult to contend with. Existing in seven forms in all, the incurable virus affects the skin, mouth, eyes or brain. One variety is responsible for chickenpox and shingles; another, for infectious mononucleosis.

While most herpes infections are symptomless, mild or merely irritating, others can be extremely distressing — notably infections affecting the genitals — and even life-threatening.

“The herpes simplex virus can cause devastating disease when you first contract it,” Reuman said. “We do not know everything about why certain people develop severe disease and why others don’t get any symptoms of the disease at all.”

Herpes simplex type 1, or oral herpes, is noted for its blister-like lesions on the face and lips, and in the mouth. Type 2, also known as genital herpes, is especially virulent.

Children who contract either variety during or shortly after birth are at risk for severe neurological complications, including seizures, coma and the rapidly progressing brain infection known as encephalitis, Reuman said. Infection also can occur if a mother has a lesion on her lips and kisses her child.

“When a child is infected with herpes within the first two months of life, whether it be type 1 or 2, it can be a very severe disease and it is something doctors worry about a great deal,” Reuman said. “Herpes can infect all the organs. No matter how fast the doctor works in terms of treating the child with antiviral medications, the child can lose 50 percent of its function.”

Up to half the individuals infected with herpes will have recurrences, often triggered by stress.

While individuals can be treated with antiviral medications to keep the virus in check, there is no known cure for herpes. Unlike an antibiotic, which kills bacteria causing an infection, an antiviral merely stops the virus from replicating within cells. Once the medication is discontinued, the virus can begin spreading again, and only the immune system can prevent this spread.

The vaccine’s development has been an international cooperative effort among members of the basic science community and industry. Nationwide, about 1,000 people have received this vaccine. About one-third noted slight side effects, including a sore arm for up to three days. Ten percent of those also developed a slight headache for a day.

The vaccine was given by injection in three doses; after the third, physicians noted excellent immune responses, Reuman said.

Now researchers seek to determine whether the vaccine actually has a protective effect by testing it in individuals who don’t have the disease but whose partners do. They are awaiting results of the double-blinded, randomized trial.

For such couples who might want children, a vaccine would be especially good news, Reuman said. The uninfected partner — and potentially the baby — would be protected.

Four other national studies are under way to determine the vaccine’s safety and effectiveness. UF is one of two sites where researchers are studying whether separate batches of the vaccine consistently produce the same immune response in individuals, and how long that response lasts. Participants, adults 18 to 45, will be tracked for two years.

“After it’s proven useful in adults, it will be tested in children to see if we can decrease the incidence of the disease and someday wipe it off the map.”