By Molly M. Ginty
Sunday, March 7, 2004
A vaccine that promises to protect female teens from herpes may be on the market in five years. Looking ahead, however, clinicians wonder how to finance and administer an STD vaccine designed for female adolescents not yet sexually active.
(WOMENSENEWS)--This spring, researchers will launch the final round of clinical trials for Herpevac, a vaccine that has proven to be 74 percent effective at preventing symptoms of herpes in young women. Herpes is the most common sexually transmitted disease.
Over the next six months, scientists from the Bethesda-based National Institute of Allergy and Infectious Diseases, the Philadelphia-based GlaxoSmithKline Biologicals, and 20 othermedical facilities nationwide plan to test Herpevac on 7,550 healthy female volunteers ages 18 to 30. If all goes well with these clinical trials, the vaccine could win approval from the Food and Drug Administration and be on the market within five years.
Already health advocates such as Yesenia Polanco, a junior at the University of North Carolina and a peer educator for Mujeres, also known as the organization Women United Together Understanding Responsibility Education and Health, are talking up news of the vaccine among their clients.
"Iâ€™m very excited about Herpevac," says Yesenia Polanco. "But a vaccine alone is not enough to solve this problem. We still need more conversation among young people, parents and community members. We still need more dialogue if weâ€™re going to stop this national health epidemic."
Researchers, meanwhile, are expressing optimism. "We hope this vaccine will prevent many herpes cases in women and thereby prevent many cases in men," says Dr. Robert B. Belshe, a professor at the Saint Louis University School of Medicine and chair of the Herpevac study. "We also hope it will reduce the number of babies born with neonatal herpes, a potentially fatal disease."
Herpes infects an estimated 60 million Americans. Though it can be effectively treated with prescription medications such as valacyclovir (Valtrex) and famciclovir (Famvir), it has no known cure. The disease is transmitted when an uninfected person touches skin or mucus membranes where the virus is active. After infection, symptoms vary widely from person to person, ranging from a tear in the skin to a rash of burning, red blisters. Lesions appear when the virus is active or "shedding," and can disappear for weeks or even years between outbreaks.
Since many herpes cases have no visible symptoms, an estimated 90 percent of carriers don't even realize they are infected. Because carriers are unwittingly infecting their sexual partners, herpes has become a national health epidemic.
The U.S. Centers for Disease Control and Prevention reports that, since the 1970s, the number of clinically diagnosed herpes cases has increased 11-fold. Each year, the disease racks up 1.6 million new cases and an estimated $1 billion in health care costs.
Though widespread, herpes is not an equal-opportunity disease. Herpes afflicts 30 percent more women than men, striking an estimated 1 in 4 women. If an infected mother transmits the virus to her baby when the child passes through the birth canal, the baby can suffer severe brain damage. Without aggressive treatment from anti-viral drugs, half the babies who contract neonatal herpes will die of the disease.
According to the latest research, herpes is of particular threat to women under 25--the population most likely to engage in unprotected sex. The American Journal of Epidemiology reported in 2001 that 40 percent of infections occur among people between the ages of 15 and 24. A report released last month by the Centers for Disease Control and Prevention, based in Atlanta, and the American Social Health Association, based in Research Triangle Park, N.C., found that 640,000 Americans ages 15 to 24 acquire herpes each year.
"One in two Americans will contract an STD by the time they're 25," says Joan Cates, a principal investigator for the study. "The human and financial costs of herpes and other STDs should serve as wake-up call for our nation." STD is the acronym used for Sexually Transmitted Disease.
Researchers have tried to develop other herpes vaccines, but Herpevac is the first to show real promise. It prevents the spread of herpes simplex virus type 2 (HSV-2), the strain of the herpes virus that usually affects the genitals. But the vaccine does have serious limitations. When it was tested in men, it failed to reduce their symptoms and rates of infection.
The vaccine only works in women--and only in those women who have never been infected with herpes simplex virus type 1 (HSV-1), the strain of the virus that typically causes cold sores on mouth. "By age 12, most kids will already be exposed to HSV-1," says Charles Ebel, co-author of the 1999 book "Herpes Controlled: New Drugs, New Strategies, New Solutions." "For this reason, adolescent administration may be the only effective delivery route."
In tests so far, Herpevac has prevented outbreaks in 74 percent of infected women. But it has only prevented herpes infection in 48 percent of uninfected women. This means the vaccine is far more effective at preventing a vaccinated person from developing symptoms than it is at preventing them from contracting herpes.
Despite these limits, Geoff Garnett, a health researcher at the Imperial College of London, predicts, based on his mathematical models, that the vaccine could achieve a 40-percent reduction in herpes prevalence in both sexes after 25 years.
Though Herpevac shows promise, health advocates worry about the practical implications of administering the vaccine to adolescent teens. Belshe says Herpevac will most likely be delivered by private doctors.
But how do you convince parents to vaccinate their 10- to 12-year-old daughters against a sexually transmitted disease? How do you get pediatricians--who usually don't deal with reproductive health--to broach the topic with their patients? How do you convince insurance companies to cover an STD vaccine for patients who aren't even sexually active yet? Some health advocates have suggested a novel solution: vaccinations at public schools.
"Across the U.S., high schools have recently started offering vaccinations for hepatitis B, another sexually transmitted disease," says Tamara Kreinin, president of the New York City-based Sexuality Information and Education Council of the U.S. "But the shame and stigma that surround herpes could make this scenario problematic. Girls lining up to get their shots could be fearful about being seen. Or they may never line up, mistakenly thinking, 'This disease is for sluts who run around a lot--not for someone like me.'"
Regardless of who administers Herpevac, health advocates agree that delivering the vaccine will require cooperation from everyone involved with female adolescents: parents, youth-service providers, teachers, clergy and policy makers. It will also require clear communication about Herpevac's limitations.
"Teens need to know that this vaccine isn't 100-percent effective at preventing infection," says JoAnn Purkey, an STD educator who runs a herpes support group in Rochester, Mich. "Will this disease make kids feel like they have free rein? Will they think, 'Now I can go out and have sex without a condom?' We need to continue educating them so they know how to protect themselves."
Molly M. Ginty is a freelance writer based in New York City.
The Alan Guttmacher Institute--
"Sexually Transmitted Diseases Among American Youth: Incidence and Prevalence Estimates, 2000":
American Social Health Association:
National Institutes of Health--
Herpevac Trial for Women: