A new "nonavalent" vaccine against nine strains of human papillomavirus (HPV) promises to stop certain kinds of cancer in both women and men, as well as genital warts.
Human papiullomavirus, also known as HPV, is probably the most common sexually transmitted disease in the world. Just in the United States, the CDC estimates, 1.6 million people have genital herpes, 1.6 million people have chlamydia or gonorrhea, but 20 million are infected with HPV, and before the introduction of the Gardasil vaccine, another six million were infected with HPV every year.
The virus is more common in the United States than other countries, but another 10 million people worldwide have symtpoms of infection. HPV infections are also relatively common in Scandinavia, where they are found in about 7 percent of the population. The virus is most frequently found in young, sexually active females aged 15 to 34, in proportion to how often they have sex, but not in proportion to how many partners they have. In some communities in the US and Europe, up to 25 percent of the population has anogenital HPV.
HPV infections are an important public health problem because they can contribute to cervical cancer in women and anal cancers in men. The virus itself does not cause cancer. It simply alters skin cell DNA so that exposure to chemicals, other viral infections, or ultraviolet light are more likely to cause cancer.
Not everyone who is infected with HPV develops cancer. However, nearly every woman who develops cervical cancer first had an HPV infection, as did:
- 90 percent of persons (most commonly men) who develop anal cancers,
- 40 percent of women who develop vulvar cancers,
- 40 percent of women who develop vaginal cancers,
- 12 percent of men and women who develop thorat cancer, and
- 3 percent of men and women who develop oral cancer.
HPV is most often described as the virus that causes cervical dysplasia and cervical cancer, but it is also one of the most important anal cancer causes. The most obvious side effect of HPV infection is the development of genital warts, which can occur just a few weeks after infection. Cancer usually does not occur until something weakens the immune system, such as treatment for a different kind of cancer, HIV, herpes, or chemical exposure, years or even decades later.
Aren't There Side Effects To Gardasil?
While HPV vaccines don't have the devastating side effects some fearmongers claim, that doesn't mean that they have no side effects at all. it's not unusual for recipients of the vaccine to have swelling, redness, or pain at the injection site for a day or two. It's relatively rare for them to have fever or fatigue, but it happens.
The original vaccine, Garadasil, was bivalent, that is, it protected against just two relatively common strains of HPV, HPV 16 and HPV 18. Next there was a tetravalent version of the vaccine, which protects against four of the most common strains of the virus, HPV 16, HPV 18, HPV 6, and HPV 11.
Oddly enough, adding more strains of virus to the vaccine reduced side effects of getting the shot, although that may be due to the fact that the tetravalent vaccine hasn't been around as long for doctors to report problems. The new nonovalent HPV vaccine, which covers nine strains of the virus, has fewer side effects still.