HPV Vaccine Considerably Reducing Cancer-Causing Virus Prevalence

Ever since the human papillomavirus (HPV) vaccine hit the market 6 years ago, the prevalence of HPV has markedly decreased among women aged 14 to 24 years.

New research published in Pediatrics compared HPV prevalence before the vaccine’s introduction (around 2003 to 2006) with the first 4 years of its availability (2009-2012). While analyzing patients’ data from cervicovaginal samples that were tested at the US Centers for Disease Control and Prevention, the researchers specifically looked at HPV types 6, 11, 16, and 18, which are included in the quadrivalent HPV vaccine.

When comparing the pre-vaccine age with the era of the vaccine’s early availability, infection rates for the 4 HPV types decreased from 11.5% to 4.3% among women aged 14 to 19 years and from 18.5% to 12.1% among those aged 20 to 24 years. Not surprisingly, HPV prevalence was also lower among sexually active women aged 14 to 24 years who were vaccinated (2.1%), compared with their unvaccinated counterparts (16.9%).

The researchers commented that the decrease in HPV prevalence following the release of the vaccine was “greater than expected based on current 3-dose coverage.”

“This outcome could be due to herd protection or effectiveness of less than a complete 3-dose series, for which there is accumulating evidence,” they hypothesized.

The HPV vaccine is designed for women aged 11 to 12 years, but pharmacists should encourage women as old as 26 years to get immunized if they have not received it yet. Pharmacists should also be sure not to neglect boys, as the vaccine has been recommended for males since 2011, and a 2015 study published in Epidemics argued that deriving the greatest benefit from a vaccine program requires a strategy targeted at both genders.

Study author Marc Ryser, PhD, suggested that pharmacists who are able to administer the vaccine in their state could promote the vaccine by sharing information about the risks of cancer from HPV.

“It is important to emphasize that the HPV vaccine is much more than a vaccine against cervical cancer, as it prevents a number of different cancers in both women and men,” Dr. Ryser told Pharmacy Times. “In addition, vaccinated males provide indirect protection to their sexual partners, thereby increasing the population benefit of the vaccine.”

While the vaccine has been successful in decreasing HPV prevalence, there is still work to be done in terms of coverage.

A 2013 survey discovered that 57% of women aged 13 to 17 years had at least 1 dose administered, and only 38% had received all 3 doses.

One challenge that public health experts have faced is the vaccine’s association with sexual activity among youth. Another challenge is the fact that few states require patients to receive the HPV vaccine.

Virginia, Rhode Island, and Washington, DC, are the only states that have such requirements. In contrast, the varicella vaccine is required in all states.

“Pharmacists can play an important role in the success of HPV vaccination efforts by reminding parents or guardians of adolescents to learn more about the vaccine and its benefits,” Jason L. Schwartz, PhD, MBE, of Princeton University, told Pharmacy Times. “If all health care professionals communicate a common, clear message in support of routine, on-time HPV vaccination, the disappointing rates observed thus far are likely to improve substantially in the years ahead.”