HPV vaccination

I had a request from a dear friend who has a daughter the same age as mine to discuss HPV vaccination.  This is a great topic for discussion, and there has been a lot of controversy surrounding the issue of mandatory vaccination by some states and schools.

First off, what is HPV?  It stands for Human Papillomavirus, which is rampant.  It's the virus that can cause you to get warts, but some types can cause cells to divide abnormally and then become invasive (cancer).  There are about 150 subtypes of HPV, and about 40 subtypes are sexually transmitted. Some types do not cause any symptoms, some cause warts (genital or otherwise), and others can cause cancer.  We call these subtypes "high risk".  When someone gets infected with HPV, very frequently the infection is cleared by his/her immune system, but sometimes the infection is persistent.  When someone has a persistent high-risk type of HPV, they are at risk for cancer.

Most genital warts are caused by two specific subtypes of HPV, namely HPV-6 and -11.

Almost all cervical cancer is caused by persistent high-risk HPV infection, and 70% of those cancers are caused by the subtypes HPV-16 and -18.  Many other cancers can be caused by HPV infection.  90% of anal cancer, 65% of vaginal cancer, 60% of oropharyngeal cancer, 50% of vulvar cancer, and 35% of penile cancers are thought to be caused by HPV.  Thankfully, these diseases are not very common, but for those who are affected, the treatment (as you can imagine) is horrific.

In 2007 (the most recent year with available data), about 12,000 women were diagnosed with cervical cancer, and over 4,000 women died of it.  I have participated in the care of women with cervical, vulvar, and vaginal cancers, and although no cancer is easy to deal with, these are among the most terrible.

In 2005, the Gardasil vaccine was FDA-approved after extensive testing.  It is a quadrivalent vaccine, meaning that it covers against 4 subtypes of HPV, the aforementioned types 6, 11 (which cause genital warts), and 16 and 18 (which cause 70% of cervical cancers).  It is given in 3 separate shots, initially and then 2 months and 6 months later.  Immunity has been documented at over 97% after the series is complete.  It is recommended for those aged 9-26 (boys and girls).

Another vaccine, called Cervarix, is also available.  It, however, is bivalent and protects only against subtypes 16 and 18, so no protection against genital warts.  It is used much less frequently than Gardasil.

There are many anecdotal reports of serious adverse effects to Gardasil, such as stroke, mental retardation, and muscle weakness.  This is one topic you may remember that presidential hopeful Michele Bachman brought up a few months ago, when making the point that Texas governor Rick Perry (also running for president) mandated that girls in Texas be vaccinated.  Many parents are scared to vaccinate their children because of these reports.  Several studies, though, have shown the safety of Gardasil, and there is an ongoing registry to report adverse events.  A link to the CDC's report is here:  http://www.cdc.gov/vaccinesafety/vaccines/hpv/gardasil.html.  In short, approximately 40 million doses of vaccine have been administered in the U.S.,  and about 20,000 adverse events have been reported.  That's about 0.05%.  Of those, 8% were considered serious, so about 0.004% of the total number vaccinated.  Serious events included anything that required hospitalization, or that caused permanent disability, life-threatening illness, congenital anomaly, or death.  It is not known whether these events were caused by the vaccine, or were just coincidence.

The CDC (Centers for Disease Control) and FDA (Federal Drug Administration) continue to recommend these vaccinations to prevent HPV-associated cancers.  Here's a link to the information sheet provided by the CDC:  http://www.cdc.gov/vaccines/pubs/vis/downloads/vis-hpv-gardasil.pdf

I do not think this vaccine should be mandatory, but rather a decision made by individuals based on the facts that are known.  I do intend to have my children vaccinated, but wholeheartedly respect the decision of others to decline the vaccine.  As with nearly all medical treatments, the risks and benefits should be carefully weighed before making the decision that's right for you.