Ten years ago, the human papillomavirus vaccination was introduced in an attempt to reduce the occurrence of HPV. Virtually all cases of cervical cancer are found to be due to the HPV virus as well as other cancers such as anal, vaginal and oral. The vaccine Gardasil by Merck, introduced in 2006, protects against four types of HPV.
In a new study published in Pediatrics, researchers compared the rates of HPV in female teens before they received the quadrivalent vaccine (2003–2006) and four years after (2009–2012) according to age group.
“Among girls 14 to 19 years old, rates of infection with the four types of HPV included in the 4vHPV vaccine decreased from 11.5% to 4.3%. There was also a drop, although smaller, in women 20 to 24 years old, from 18.5% to 12.1%. Among the older groups, women ages 25 to 29 and 30 to 34, the prevalence of these HPV types did not change and was about 12% and 9%, respectively,” reported CNN.
This equaled a 64 percent reduction among females aged 14 to 19 years, and a 34 percent decrease among those aged 20 to 24 years.
Dr. Lauri E. Markowitz, a medical epidemiologist at the CDC and lead author of the study told CNN, "Eventually we expect to see decreases in HPV in older groups as women who were young (enough to get the vaccine) age."
Despite the fact that only about 40 percent of girls and 20 percent of boys are immunized here in the United States, the study shows that vaccination has made an impact on the incidence of HPV.
The difficulty in getting more young people vaccinated is due to a number of issues.
For full coverage, three shots are currently required. Getting compliance of parents and young people to return three times for a vaccination can be difficult and current research indicates that two shots might be as effective as three. Markowitz will be meeting with the Advisory Committee on Immunization Practices to discuss reducing the schedule to two.
The attitudes of parents and doctors in the United States have contributed to lower compliance rates. In Australia and the UK, over 80 percent of boys and girls are vaccinated, according to Markowitz. Part of the reason is that the vaccinations of preteens take place at school, removing the obstacle of having to get them to the doctor’s office.
The HPV vaccination has received some stigma as being a shot connected to sexual promiscuity and certain side effects. Dr. Sarah Feldman, co-director of ambulatory gynecologic oncology at Brigham and Women's Hospital, expressed to CNN that she hopes that attitude will diminish.
"More and more, it's becoming clear that this is a cancer prevention vaccine, and if we could get 100% of our boys and 100% of our girls vaccinated, we could probably eradicate the worst HPV types," Feldman said.
This year a new HPV vaccine called 9vHPV, approved in 2014 is being released and will protect against nine types of HPV. The vaccination is recommended for girls and boys ages 11 to 12.
In the future, the CDC also plans to study the incidence of oral HPV infections related to oral cancers since the vaccine has been available. It is thought that in the next few decades, oral cancer caused by HPV will outnumber the cases of cervical cancer.
Michele is an R.N. freelance writer with a special interest in woman’s healthcare and quality of care issues.