One-day fight against herpes
The first outbreak was devastating enough. But within weeks came another outbreak. Then another and another.
For Gina Caprio, then 22, the virus that causes genital herpes was nightmarish, “like my life was over.”
An antiviral drug managed to keep the virus under control, preventing recurrences, but she had to take it every day, year-round. For years, that costly and inconvenient regimen has been the lesser of two negatives, not just for Caprio but for the millions of Americans with genital or oral herpes.
Now they have a better choice.
The Food and Drug Administration recently approved two new dosing regimens for the herpes drug Famvir that, used properly, can work in a single day to prevent or curtail an outbreak.
The single-day dosing culminates 25 years of advances against the herpes viruses, researchers say. And the best advance may be yet to come. A vaccine that could prevent herpes in women is being studied -- and the results seem promising.
Three decades ago, no one could have anticipated such success against herpes.
“Herpes is a difficult disease to treat. For years people said it was untreatable,” says Dr. Spotswood Spruance, an infectious diseases expert at the University of Utah. “There’s a big difference between what we had in the past and the simplicity of this new treatment.”
An estimated 50% to 80% of all Americans are infected with the herpes simplex virus type 1, which primarily causes cold sores. Most people are infected during childhood through skin-to-skin contact. HSV-1 can also cause genital infections.
Herpes simplex virus type 2 primarily causes genital blisters and is sexually transmitted. About 20% of American adults have HSV-2.
The severity of infections varies widely. Some people have no symptoms and are unaware they are infected. In those who do have obvious outbreaks, symptoms can range from severe and frequent to mild and infrequent.
“It’s a minor illness. But it’s a nuisance to many people, and it can be painful and distressing to some,” Spruance says. “When it occurs every month or so, people describe it as a serious health problem.”
Treatment options evolve
Until 1982, when the first antiviral ointment, acyclovir, was introduced, people with herpes simply suffered through their outbreaks. Acyclovir represented a new class of drugs, called nucleosides, that block viral reproduction.
Once they invade the body, herpes viruses take permanent shelter, nestling quietly in nerve cells until something -- illness, stress, sunburn or unknown factors -- causes the virus to awaken and begin to replicate. Though these early hours of virus activity can produce symptoms, such as tingling, the blisters don’t form until later, providing a window of opportunity to stop or limit their formation.
A pill form of acyclovir was introduced in 1985. And drugs that are absorbed more effectively and require fewer doses -- Valtrex (valacyclovir) and Famvir (famciclovir) -- followed. An ointment for cold sores, Denavir (penciclovir), is also available.
“This class of drugs, the nucleosides, is now the standard of care,” says Dr. Stephen Tyring, a professor of dermatology at the University of Texas Health Sciences Center at Houston and the chief investigator of a study on genital herpes and single-day dosing of Famvir.
Over the years, doctors have also learned that the medications can be taken in higher doses and for shorter amounts of time, such as three days, particularly when started at the first sign of an outbreak. The single-day Famvir regimens are the latest approach to nipping outbreaks quickly and easily, and also provide guidelines about how soon the medication must be started to prevent or curtail the blisters.
For cold sores, the FDA has approved one 1,500-milligram dose (three 500-milligram tablets) that should be taken within one hour of the first sign of symptoms, such as burning, itching and tingling.
For genital herpes, a 1,000-milligram dose taken twice daily for one day should be effective if taken within six hours of the first sign of an outbreak.
“We knew the earlier you take it, the better. But the high dose and short duration also proved effective and that was a pleasant surprise,” Tyring says. “This will appeal to patients because it is so convenient compared to the way it was taken in the past.”
The cold sore studies show that the single-day dose, if taken within the appropriate time frame by people with healthy immune systems, shortened outbreaks by about two days and reduced the pain and tenderness of the blisters. It did not prevent outbreaks. However, in the genital herpes study, single-day dosing prevented outbreaks in about half of the people and shortened the outbreak by about two days in the other half.
It’s crucial to have the medicine handy and take it right away for the best chance of stopping an outbreak, says Spruance, the lead investigator of the cold sore study. The tingling, itching or burning sensation is a sign that the virus has become active and is replicating. Most herpes sufferers can identify those symptoms easily, he says. “They know when they’re getting one.”
Caprio, now 30, says she has abandoned daily preventive medication and will now carry the single-day dose with her to prevent outbreaks.
“I think it’s awesome,” the New Jersey woman says. “The problem with herpes is that when you have breakouts, they last a week -- a week of pain and symptoms. If you can identify the symptoms and have the medication on hand and wipe it out, that really helps you emotionally.”
Most doctors believe that not enough people obtain treatment for herpes. Even those with infrequent outbreaks should inquire about medication, experts say. Herpes can be transmitted during outbreaks and even when someone is asymptomatic. Moreover, a pregnant woman with an active infection -- whether symptoms are apparent or not -- can transmit the virus to her baby at birth, causing serious problems such as seizures, blindness, spasticity or death.
“People with mild or infrequent outbreaks are unlikely to seek medical attention,” Tyring says. “But they could still spread it to someone else, or a baby could be born to a mother who has it. That is the worst-case scenario.”
Now, focus is on vaccine
The recent approval of one-day dosing of Famvir suggests that researchers have gotten the most they can out of the nucleosides, Spruance says. “These latest trials represent the last point on the learning curve with these drugs. We’ve really reached the end of this paradigm.”
But a new research focus is emerging -- one that aims to prevent herpes infections. A government-funded study testing a herpes vaccine is underway at more than 20 sites across the country. The study of 7,500 women will examine whether the vaccine, given in three doses within six months, can prevent infections in women ages 17 to 35 who have not been exposed to either HSV-1 or HSV-2.
Earlier studies of the vaccine showed it wasn’t effective in women who were already exposed to either or both of the viruses. It also didn’t work in men. But it was found to protect against infection in more than 70% of women who weren’t previously exposed to HSV-1 or HSV-2.
Experts aren’t sure why the vaccine doesn’t work in men. However, if the vaccine is eventually approved in women, widespread immunization could help protect men too, says Dr. Joel Ward, director of the Center for Vaccine Research at UCLA and the lead investigator for the local arm of the vaccine trial.
“If it’s not circulating in the population, then men won’t get herpes,” Ward says.
The study is scheduled to conclude next year and, if successful, would be the second vaccine against a sexually transmitted disease. A vaccine against human papilloma virus, which can cause cervical cancer, was approved this year for use in girls and women ages 9 to 26.
How well that vaccine, called Gardasil, is accepted by the public may point to the success of a future herpes vaccine, experts say. Vaccines for STDs need to be administered in childhood, well before the initiation of sexual activity. But parents may prove reluctant to consider their child’s risk for infection later in life.
“Everybody is interested in what the public response will be to Gardasil,” says Dr. Judy Falloon, the chief medical officer for the herpes vaccine trial at the National Institutes of Health. It may be harder to convince parents of the importance of a herpes vaccine, she says. “HPV can be thought of as a cancer vaccine. It doesn’t have the stigma of an STD. Herpes is very stigmatized.”
Ward believes that once parents understand the benefits, they won’t hesitate to protect kids from any potential threat.
“Over the next few years, young teens, ages 10 to 12, will be offered a number of vaccines that can make their adult years safer than our adult years,” he says. “If I can prevent anything, why not do it?”
