Scientist Works on Single Vaccine Against Herpes, Other Diseases

A single immunization administered to children may some day prevent herpes, hepatitis, chicken pox and mononucleosis, says a virus expert who is working to develop such a vaccine.

“Don’t be overly optimistic,” University of Illinois virologist Bernard Roizman said recently. He stressed that a multiple-virus vaccine or even a vaccine for herpes simplex alone won’t be available for at least five years.

“If and when we have a herpes simplex vaccine, we can use it as a vaccine to immunize against other infections,” he said. Those infections include hepatitis-B, chicken pox, mononucleosis--the so-called teen-age “kissing disease”--and cytomegalovirus, which is America’s leading infectious cause of birth defects.

Roizman outlined his efforts to develop herpes and multiple-disease vaccines at the American Society for Microbiology’s annual meeting, attended by an estimated 10,000 scientists.

Over the last five years, Roizman and other researchers have worked to alter the herpes simplex virus by inserting or deleting genes--the instructions that give the virus its characteristics--so the microbe won’t cause disease when injected but will provide immunity to oral and genital herpes.

Prototypes Being Tested

Two prototype herpes vaccines are being tested in hundreds of animals, he said.

“If the vaccine is successful, we then can add other genes to the vaccine to protect against more than one disease,” he said.

Genetic instructions from various disease viruses could be inserted into the altered herpes virus, which would carry them “piggyback style” in a vaccine, he said. Those instructions and the modified herpes virus together would tell a person’s immune system to make antibodies to prevent herpes and the other diseases.

Roizman already has inserted genetic material from the hepatitis-B virus into a disease-causing herpes virus and within weeks will try inserting it into one modified not to cause disease. That will be the next step toward a possible hepatitis-herpes vaccine.

The method differs from the technique used to make the vaccine that simultaneously combats diphtheria, whooping cough and tetanus. That method does not use the gene insertion technique.

Work on Smallpox Virus

Researchers in Albany, N.Y., and the National Institutes of Health are using Roizman’s method to place genetic material for various diseases into the smallpox virus with the goal of creating a vaccine effective against smallpox and other infections.

But with smallpox nearly eradicated, Roizman believes it will be more beneficial to use a herpes virus in a vaccine against multiple diseases.

His approach uses a modified live herpes virus rather than a killed one because a herpes vaccine must be powerful enough to provide lifetime protection so immunizations can be given in childhood, he said. Adults are notoriously poor at following recommendations to get vaccinated, he added.

“You have to live with the facts of life,” Roizman said. “Americans generally don’t go to get vaccinated just before they go to singles bars.”