Author: University of Chicago Medical Center, reviewed by Kate Anderton, B.Sc. (Editor)
The vaccine that prevents infection from human papillomavirus (HPV) is nothing short of a medical marvel. “It’s one of the most effective vaccines we have against any disease or infection. And it prevents cancer,” said Andrea Loberg, MD, clinical associate of obstetrics and gynecology.
Pre-teens and teens who are vaccinated against HPV can be spared some of the deadliest, most disfiguring and hard-to-treat cancers-;those of the cervix, vagina, vulva, penis, anus, mouth and throat. Over 90% of cancers caused by HPV can be prevented-;29,000 cases of cancer per year-;with the HPV vaccine.
Concerns about sexual promiscuity
To some parents, however, the HPV vaccine may be an uncomfortable reminder that their child will be moving into adulthood and may choose to express his or her sexuality. HPV is transmitted by oral, vaginal and anal sex and other intimate skin-to-skin contact, and it is extremely prevalent; about 80% of people will be exposed to the virus in their lifetime.
Condoms reduce but don’t eliminate the risk of HPV infections because the virus lives in both oral and genital tissues. Condoms do not cover the entire genital area of either gender. Nor are same-sex female partners protected from contracting the virus, which often causes no symptoms until precancerous lesions or cancer show up years later. “It’s hard for parents to think about our kids becoming sexually active, but we also want them to have fulfilling lives,” said Truehart, whose own two teenagers have received the HPV vaccine. “We want to make sure they are protected before they start having sex.”
The recommended age for receiving the HPV vaccine is 11 or 12, when children are also scheduled to receive the Tdap vaccine (tetanus, diphtheria and pertussis) and the meningitis vaccine. But the two-dose vaccine-;the second dose is given six to 12 months after the first-;can be given to children as young as nine. Teens older than 15 and men and women need three doses of the vaccine to develop an immunity against HPV.
“Pre-teens have a more robust response to the vaccine and generate enough antibodies to protect against HPV after two immunizations, whereas older kids and adults need three doses to get the same immune response,” said Truehart. Another reason not to delay getting the HPV vaccine: an older teen may not want to wait six months or more to be fully immunized against HPV once he or she is on the verge of becoming sexually active. “It’s important for kids to be immunized before they are exposed to HPV,” Truehart said.
Not just for girls
When the U.S. Food and Drug Administration approved the HPV vaccine in 2006, it was recommended for girls and women to protect against cervical cancer. Three years later, the vaccine was approved for boys and men, based on evidence that males are also susceptible to HPV-related cancers. “Cancers caused by HPV affect women and men in equal numbers,” said Loberg. “Each year, there are approximately 10,800 cases of cervical cancer diagnosed in women, and 9,600 cases of head and neck cancer diagnosed in men.” And while there is a screening test for cervical cancer to catch and treat it early, there are no such screening tests for any of the other HPV-related cancers. And because most HPV infections are asymptomatic, people may be unwittingly transmitting the infection to their sexual partners.
HPV also causes genital warts which, although not harmful in most people, can be embarrassing and unsightly. In some cases, however, genital warts can be extremely painful and may even require surgery to remove them. For people with autoimmune disorders or who take medications that compromise their immune system, genital warts can be very difficult to manage, said Loberg. Out of more than 150 strains of HPV, the vaccine targets the most prevalent and harmful ones: two strains that cause genital warts and seven strains that cause various types of cancer.
No serious side effects
Despite HPV being the most common sexually transmitted infection, HPV-related cancers are relatively uncommon because in about 90% of people exposed to HPV, their immune systems clear the virus from their bodies before it causes cancer or precancer. “But we don’t know which individuals will develop a persistent infection, so why take that gamble when cancer can be the consequence?” said Loberg.
When parents ask whether the HPV vaccine is safe, Loberg’s ready answer is that “it’s incredibly safe.” More than 270 million doses of the HPV vaccine have been distributed worldwide since 2006, and there have been no serious side effects. One study that examined data from more than 56 million doses of HPV vaccine administered in the U.S. found that some girls became dizzy or fainted 15 minutes after receiving the vaccine. “That is the only side effect that we see,” other than mild side effects typical of other vaccines, such as fever, headache, and pain and redness at the injection site, said Loberg.
Pediatricians and primary care providers should be recommending the HPV vaccine for children, but if not, parents should bring it up.
“There is absolutely no downside to getting the HPV vaccine, and the upside is preventing your child from getting a deadly or disfiguring cancer,” she said.