Observations Yankee Doodling

HPV vaccine: effective but underused in the US

BMJ 2016; 353 doi: https://doi.org/10.1136/bmj.i2060 (Published 14 April 2016) Cite this as: BMJ 2016;353:i2060
  1. Douglas Kamerow, senior scholar, Robert Graham Center for policy studies in primary care, Washington, DC, professor of family medicine, Georgetown University, and associate editor, The BMJ
  1. dkamerow{at}aafp.org

Doctors’ policies can allow for sexual anxiety in parents

In most young women and men the human papillomavirus (HPV) is an innocuous sexually transmitted infection, asymptomatic, and eventually cleared without consequences. In some people, however, HPV infection becomes chronic and leads to cancer (mainly cervical, but also anal, penile, oral, and throat cancers) or genital warts. The HPV types 16 and 18 together cause 70% of cervical cancers.

Vaccines to prevent HPV were licensed in the United States and recommended for all adolescent girls in 2006. Recommendations to vaccinate boys started in 2011. The good news, recently confirmed in a US study of females aged 14-34, is that HPV vaccine can prevent HPV infection1; the bad news is that we’re not doing a good job of getting the vaccine into our children.2

The US Advisory Committee on Immunization Practices and other authorities recommend a three dose regimen of HPV vaccine for girls and boys aged 11-12. A 2014 study, however, found that only 37.6% of girls and 13.9% of boys aged 13-17 had received the full, three dose course of HPV vaccine in 2013.3 This compares poorly with other vaccines administered at that age—most notably, diphtheria-tetanus-pertussis vaccine (Tdap), which reaches over 80% of US teenagers.

Dreadful coverage rate

Despite this rather dreadful coverage rate the vaccine has already reduced HPV infection rates in the US. In a study published in February, researchers found substantial reductions in the prevalence of the HPV types included in the vaccines among young women, comparing the four years before and since the vaccines’ introduction—a 64% decrease in those aged 14-19 and a 34% decrease in those aged 20-24.1 What this does not show, of course, is a decrease in cancer rates or deaths: those data will require longer term studies.

Not surprisingly, many opportunities to deliver HPV vaccine are missed, given that teenagers routinely get Tdap shots. But there are also many barriers to HPV immunization.

Firstly, in the US the HPV vaccine is given as a three shot regimen (some countries use a two dose vaccine), and the percentage of people vaccinated decreases as the number of required doses increases.

Secondly, HPV vaccination is required for school entrance in only two US states and Washington, DC, and state mandates are a major driver of vaccine behaviors. Most state legislatures have considered requiring HPV vaccine but have rejected it because of political squeamishness about vaccinating 11 year olds against a sexually transmitted infection.

Thirdly, and related to this, is parents’ lack of interest in the vaccine because they haven’t heard of it or have heard that it’s for a sexually transmitted disease, and their 11 year old isn’t sexually active. Or they’re afraid that being vaccinated will increase the chances that their child will become sexually active. This latter explanation, which has been shown to be false,4 is reputed by many to be the major barrier to HPV vaccination.

In fact, studies surveying parents have found that the leading barriers to HPV immunization are all related to medical system failures: parental lack of knowledge about the vaccine, a belief that it isn’t needed, and parents reporting that it hadn’t been recommended to them by their doctors.3

Vaccine against cancer

Clearly, in the US we’ve done a poor job of integrating this vaccine, the only one that exclusively targets cancer, into the regimen of jabs that we give our young patients. It’s often discussed as an added option, instead of being presented as standard care along with other routinely administered vaccines.

A smart family doctor told me that she presents the HPV vaccine as one that every 11 year old gets, naming the infections and cancers that all of these vaccines target. If parents express concern that HPV vaccine is for a sexually transmitted disease, she points out that they didn’t object when their child received hepatitis B vaccine as an infant. That can also be sexually transmitted.

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