by Sanjay Gupta
The sexually transmitted human papillomavirus, or HPV, was in the news this month after actor Michael Douglas suggested it may have been the cause of his throat cancer. HPV affects nearly 80 million Americans, with about 14 million new cases reported each year, and it’s the leading cause of cervical cancer. New research shows that HPV vaccines are highly effective, yet vaccination rates remain low in this country.
According to a study in the June issue of The Journal of Infectious Diseases, vaccinations helped reduce HPV rates by half among women ages 14 to 19 since the first vaccine was approved in 2006. U.S. Centers for Disease Control and Prevention director Dr. Tom Frieden called the findings “a wake-up call that we should increase vaccination rates.” But misconceptions persist about HPV, its risks, and prevention.
HPV is a group of more than 150 related viruses, most of which trigger no symptoms or may cause noncancerous growths known as papillomas or genital warts. About 90 percent of HPV infections go away on their own within a couple of years. There are “high-risk” HPVs, however, that are carcinogenic. Besides cervical cancer, which is diagnosed in about 12,000 women and claims 4,000 lives a year, HPV can cause genital as well as throat and mouth cancers.
“Our immune systems can usually reduce the load of HPV virus in our system, so there’s a very low concentration in the body that’s not doing any harm,” said Alan Waxman, MD, professor of obstetrics and gynecology at the University of New Mexico School of Medicine. “The problem happens when the amount of cancer-causing strains overwhelms the immune system, which in turn causes the cancer.”
According to the American Congress of Obstetricians and Gynecologists, 8 out of 10 women will contract HPV by the age of 50. Men can also become infected, and “it’s absolutely something the male population should be aware of,” said Dr. Waxman.
There are two HPV vaccines on the market: Gardasil, which has been tested and licensed for both men and women; and Cervarix, which has been approved only for women. Both vaccines protect against HPV types 16 and 18, which cause many of the HPV-associated cancers. Gardasil also protects against HPV types that cause genital warts.
The vaccines are most effective when given before a person is sexually active, according to the Mayo Clinic. “It’s during the first instances of sexual contact that a person is at the highest risk for HPV, so you’d want to be protected before then,” said Kim Fallon, MD, a gynecologist who specializes in adolescent health at the Valley Medical Group in Ridgewood, N.J.
The National Cancer Institute reports that vaccination “has been found to prevent nearly 100 percent of precancerous cervical cell changes” for up to five years with Gardasil and up to six and a half years with Cervarix.
HPV vaccination hasn’t been without controversy. The CDC recommends boys and girls between the ages of 11 and 12 be vaccinated because “you get a really robust immune response from kids that age, which results in better protection,” according to Dr. Fallon. But some parents worry about possible side effects or that vaccinating children encourages sexual behavior. A study in the March issue of Pediatrics suggested that nearly half of parents refuse to vaccinate their kids.
According to the Mayo Clinic, the vaccines’ most common side effects are relatively mild and include flu-like symptoms and soreness at the injection site. There have been rare instances of more serious allergic and neurological side effects, but it’s unclear if they were caused by the vaccines.
“Parents ask why we want to vaccinate an 11-year-old for an STD [sexually transmitted disease], but building that immune response before they’re exposed is so important,” Fallon said. “We’d like to get to a point where there’s not a stigma around the vaccine [because] it’s about protecting a person’s health.”
Dr. Sanjay Gupta is CNN’s chief medical correspondence. This article was culled from Everyday Health.
