Trending Clinical Topic: HPV

Ryan Syrek


November 19, 2021

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Despite a new study showing a major benefit from human papillomavirus (HPV) vaccination, recent data show increasing hesitancy and safety concerns associated with the vaccine. These conflicting findings, released very close to one another, generated substantial interest and resulted in this week's top trending clinical topic.

On the positive side, new research from England demonstrates the success of a national program to vaccinate girls against HPV (see Infographic below).

The new data come from a population-based cancer registry that shows the incidence of cervical cancer and noninvasive cervical carcinoma (CIN3) in England between January 2006 and June 2019. The national HPV vaccination program in England began in 2008. Initially, the bivalent Cervarix vaccine against HPV 16 and 18 was used. In 2012, the program switched to the quadrivalent HPV vaccine (Gardasil), which is also effective against two additional HPV types, HPV 6 and 11. Those strains cause genital warts. The study included seven cohorts of women who were aged 20-64 years at the end of 2019. Three of these cohorts composed the vaccinated population. Those cohorts had around 450 fewer cases of cervical cancer and 17,200 fewer cases of CIN3 than expected in a nonvaccinated population.

In the United States, hesitancy about the HPV vaccine remains high. New findings were presented at the American Association for Cancer Research Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved. Nearly two thirds of American parents are on the fence about vaccinating their children for HPV. Overall, vaccine hesitancy dipped from 69% in 2010 to 63% in 2019. On an annual basis, vaccine hesitancy decreased 6% from 2010 to 2012 and then increased slightly (0.6%) from 2012 to 2019. Among younger mothers (aged 35-44 years), average vaccine hesitancy fell 5.88% from 2010 to 2012 and remained stable thereafter. Among mothers aged 45 years or older, average vaccine hesitancy dropped 3.92% from 2010 to 2013 and then remained stable.

Perhaps fueling the hesitancy, new research found a dramatic rise in concerns about the HPV vaccine's safety. Despite a decrease in reported adverse events, concerns about the vaccine's safety rose 80% from 2015 to 2018 among parents of unvaccinated adolescents. Since its approval in 2006 by the US Food and Drug Administration, uptake of the HPV vaccine has consistently lagged behind other routine vaccinations. According to the most recent data from the Centers for Disease Control and Prevention, released September 3, 58.6% of adolescents were considered up to date with their HPV vaccinations in 2020. The top five reasons caregivers cited for avoiding the HPV vaccine were the following:

  • Not needed or necessary

  • Safety concerns

  • Not recommended

  • Lack of knowledge

  • Not sexually active

Of these, safety concerns were the only factor that increased during the study period. They increased from 13% in 2015 to 23.4% in 2018.

The benefits associated with avoiding HPV infection continue to mount, as a new study showed that persistent HPV 16 and HPV 18 during a pregnancy may be associated with an increased risk for premature birth. Researchers found that 15.9% of individuals who had a persistent HPV 16 or 18 infection during the first and third trimesters of their pregnancy gave birth prematurely, compared with 5.6% of those who did not have HPV infection at all. The study found that HPV infections were frequent in pregnancy even among populations "considered to be at low risk based on sociodemographic and sexual history characteristics." The authors hope the findings will strengthen support for HPV vaccination. The divide between evidence in favor of the HPV vaccine and a resistance to get vaccinated resulted in this week's top trending clinical topic.

Read more clinical information on HPV.


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