In the 10 years since the human papilloma virus (HPV) vaccine first became available, a series of new studies have come out showing just how effective the virus really is and how HPV vaccination rates can be improved in adolescents.
While little was known about the virus a few decades ago, HPV and its impact on human health came to light when years of research culminated in the 1995 International Biological Study on Cervical Cancer Group
’s finding that 93% of cervical cancer specimens contained HPV DNA. Further studies
found that HPV causes more than 99% of cervical cancers. Now, more than 80 million people in the United States are currently infected with HPV. According to the Centers for Disease Control and Prevention
(CDC), there are more than 150 identified forms of HPV, and each strain is denoted with a number. While cervical cancer– largely from HPV 16 and HPV 18– is the most common cancer caused by HPV infections, they can also lead to vulvar, vaginal, penile, anal, and throat cancers. The World Health Organization notes
that in 2008 there were more than half a million new cases and 274,000 deaths from cervical cancer, and virtually all of those cases are linked to persistent genital HPV.
Officials at the World Health Organization stress that the HPV vaccine is an important tool when it comes to the eradication of these preventable cervical cancers. There are some 14 million new cases of HPV each year, and to curb that, the CDC recommends that children receive the full HPV vaccine
series at age 11 or 12, well before they become sexually active. Doctors administer the vaccine in a series of three shots, which when given during the preteen years, incites a stronger immune response. Young women and men can receive the vaccine through age 26 and 21 respectively.
A new study
published in JAMA Oncology,
shows that since the introduction of the HPV vaccine there has been a significant reduction in the rates of high-grade cervical intraepithelial neoplasia (CIN), which is caused by persistent HPV infection and can lead to invasive cervical cancer. The study analyzed data collected from women ages 15 to 29 from January 1, 2007 through December 31, 2014, in the New Mexico HPV Pap Registry, a surveillance program on cervical screenings for women in the state. The researchers studied rates of CIN grade 1 (CIN1), CIN grade 2 (CIN2), CIN grade 3 (CIN3), carcinoma in situ, and adenocarcinoma in situ. By 2014, about 40% of women ages 13 to 17 had received all three doses of the HPV vaccine and the researchers found a correlating and significant population-level decrease in the incidence rate of all grades of CIN for female individuals 15 to 19 years old, and in the incidence of CIN2 for women 20 to 24 years old. In women between the ages of 15 to 19, rates of CIN1 and CIN2 dropped by more than 50% and the reported cases of CIN3 dropped from 240 to none.
“Reductions in the incidence were greater than anticipated based on HPV vaccination coverage in the population and the proportions of CIN attributable to HPV types directly targeted by the vaccine (HPV-6, HPV-11, HPV-16, and HPV-18),” write the authors. “Cross-protection against non-vaccine HPV types, efficacy of less than 3 vaccine doses, and herd immunity
may likely be contributing to these observations.”