Last week, reports highlighted a possible increased risk of pain and fainting from the new human papillomavirus (HPV) vaccine Gardasil when compared to other vaccinations.
It is unclear why young women and girls are experiencing more pain than with other vaccines — the shot is given in the shoulder, and the pain generally occurs only at the site of injection — but the minor discomfort is temporary and has not been associated with other complications. With this in mind, it is clear that the small amount of pain is well worth the protection from cervical cancer, a potentially fatal disease.
But in order to truly realize how much protection this temporarily painful prick can bestow, it helps to first understand what exactly HPV is, and how it can lead to cancer.
The term human papillomavirus actually refers to a group of 100 DNA viruses that may cause warts (or papillomas), which are benign tumors. Common warts that are usually seen on hands and feet are caused by HPV. About 40 types of HPV can infect the skin in the genital area.
HPV is spread from one person to another from skin-to-skin contact during sexual activity. Since HPV is mainly a "silent infection" — meaning it usually does not cause symptoms — it is usually impossible to know when a person became infected or who gave it to them.
Genital HPV is the most common sexually transmitted infection in the United States, with approximately 6.2 million people becoming newly infected each year.
It is estimated that nearly one out of every four females between the ages of 14 and 59 in the United States are infected with HPV, and that on average, a woman has an 80 percent chance of becoming infected during her lifetime. Recent studies suggest HPV is just as common in college-age men.
Most people with genital HPV infections are unaware that they were exposed or infected and the virus goes away on its own after one to two years.
There are about 15 types of HPV that cause illness and are classified as either low-risk or high-risk HPV types. Infections with these types of HPV can persist for many years and even decades. The low-risk types of HPV can cause genital warts while the high-risk types can persist for many years and may develop into cancer of the cervix, vulva, vagina or anus.
Cervical cancer is the second most common cancer in women. Approximately 10,000 women are diagnosed with cervical cancer each year in the United States, resulting in nearly 4,000 deaths per year.
HPV infections in women are usually diagnosed by seeing abnormal cervical cells under a microscope after a Pap test. These abnormal cells are ones that have been infected by HPV and are now either cancer cells or cells that might become cancer.
Your physician can also do an HPV test on the cervical cells to detect the type of viral DNA present. This test can determine whether the infection is due to a high-risk type of HPV.
There is currently no HPV test on the market for men.
Because HPV is so common and most people don't know that they are infected, the only sure way to prevent infection is not to have sex.
Being in a mutually faithful monogamous relationship with someone who has had no other or few prior sex partners can reduce the risk of HPV. Condoms will lower the chance of catching or spreading HPV, but does not prevent HPV entirely since some areas of the skin are uncovered.
A recently released vaccine will prevent infection with the types of HPV that cause the most disease. The vaccine can prevent the two types of HPV that cause 90 percent of genital warts and the two types that cause 70 percent of the cervical cancers.
The Gardasil vaccine, manufactured by Merck, is approved by the Food and Drug Administration for use in females between the ages of 9 and 26 years old, and the U.S. Centers for Disease Control and Prevention has recommended it for all girls between 11 and 12 years old.
Three shots are given over six months at a cost of approximately $360. A federal program called Vaccines for Children will provide free vaccine for girls younger than 19 years old who are uninsured, are on Medicaid or do not have health insurance that covers the shots.
The vaccine is most effective if given before females becoming sexually active. There is less benefit if you are already infected with one of the four types of HPV in the vaccine.
The CDC bases its recommendations on surveys of teenagers about when they become sexually active. The young age does not mean this is when most girls begin to have sex, but rather when a significant portion report becoming sexually active. Parents should talk with their children and determine when it is appropriate for their child to consider getting vaccinated.
No. There are some types of HPV that are not covered by the vaccine. A Pap test will detect abnormal cells if you are infected with one of these types. Also, we are unsure how long the vaccine will prevent HPV infections so there may be a need to get a booster dose in about five years.
An additional HPV vaccine is likely to be approved early this year. This vaccine is also intended to prevent the initial infection with HPV so it is also recommended for young women.
There are current trials that are studying the use of HPV in men and older women. A more potent HPV vaccine, which produces a vigorous immune response, is being tested as a treatment for genital warts. Finally in the near future, DNA technology could replace the Pap test with a rapid, simple, accurate and affordable test to screen for all high-risk HPV strains.
While no one enjoys getting shots, the mild pain experienced by young women from the HPV vaccine injection is well worth the future benefits in protecting against cervical cancer.
Dr. Douglas Holt is director of the Hillsborough County Health Department in Tampa, Fla., and a professor in the Division of Infectious Disease and International Medicine at the University of South Florida College of Medicine.