Blog | Friday, June 21, 2013

Gardasil is good

Crowdsourcing of medical decisions seems to be more and more common. Spend even a little time on Twitter or Facebook and you will see people posing medical questions to "the crowd." Since crowdsourcing is inevitable, it does no good to whine about the questionable practice of asking groups of (not so) random people for medical opinions. Medical professionals have an obligation to educate, and these questions can generate useful and lively discussions; they are opportunities.

The other day a friend (a real friend) posed a question on Facebook: Should she get her kid a Gardasil shot. Gardasil (NYSE:MRK) is a vaccine that protects against infection with human papilloma virus (HPV). The virus causes genital warts and a number of cancers including cervical, penile, and oral cancers. The vaccine protects against these, but to be effective, it should be given before a child is sexually active (the usual advice is nine years old), an idea upsetting to some people.

The responses to her question ranged from "Do it!" to "Are you crazy? No way!" This gives us a great opportunity to examine her question and answer with facts that can help parents make decisions. There will be no "naming and shaming" here, just answers to the comments and questions culled from the discussion.

"Go read with Dr. Mercola has to say." If you're not familiar with the world of medical conspiracy theories, you might not be familiar with Joe Mercola, a family practice doc in Illinois. He is way out there. Those of us who monitor wacky and dangerous medical ideas think of his website as a "target-rich environment," a place to find the most misguided and false medical advice. This response is simply a call to recognize the authority of an internet doctor who has a terrible reputation among most other medical professionals. Needless to say, Mercola doesn't like Gardasil and publishes a ton of questionable pieces on the topic.

"The shots only prevent a few strands of the virus when there are so many more. My OBGYN also told me the other day that most young women will have HPV during their teen years but those cases should clear themselves up before they're 21." We'll ignore the incorrect biology here ("strands of the virus" probably means "strains," but the correct terminology is "types"). The truth is Gardasil only protects against four of the 120 types of HPV, but these are the types that matter. Types 16 and 18 cause about 70% of cervical cancers and nearly all of the other HPV-related cancers. Types 6 and 11 cause most genital warts, and while warts don't lead to cancer, they are certainly a public health problem. And while it's nice that "most cases should clear themselves up" this is not always the case. Pap smears are our current method of early detection for cervical cancer. The test is pretty good, but certainly not better than prevention. I would hate to deny someone the vaccine simply because the disease "should clear itself up," and then have to explain to them why they have cancer.

"Has your child tended to have bad reactions to other vaccinations? Does your child have food intolerances and allergies, or some other auto-immune problem? Then you might not want to give it ... But I guess if there is a chance that it saves some people from developing cervical cancer it is worth it if the child is otherwise healthy and robust." Allergies and "auto-immune" problems aren't relevant. In fact, people with immunodeficiencies such as HIV are much more susceptible to cervical cancer and other HPV-related cancers. A child does not have to be "otherwise healthy and robust" to benefit from the shot.

Other arguments against the HPV vaccine also fail to hold water. Despite sensational news reports, the shot has not caused an epidemic of fainting or led to deaths. The national Vaccine Adverse Event Reporting System (VAERS) is a clearinghouse for reports of vaccine side effects. It is simply a collection of people's stories and health officials try to follow up on them to see if they have any merit. If you wished, you could make a report to VAERS that Gardasil caused you to become a communist. It's a system designed to gather as much data as possible without regard to quality. The quality control comes on follow up, where most "reactions" have been found to be either minor ("irritation at injection site," "feeling faint") or unrelated to the vaccine.

Merck, the maker of Gardasil certainly hopes to profit from the drug (doctors usually make very little or even lose money on vaccines). The fact that there is a profit motive does not make the vaccine bad, it simply means that any data coming directly from Merck should be given a bit more scrutiny. The HPV vaccine is a good one, and protects against several important cancers. My kiddo is going to get it as soon as she next visits the doctor, and if I had a son, he'd get one too.

Peter A. Lipson, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. After graduating from Rush Medical College in Chicago, he completed his internal medicine residency at Northwestern Memorial Hospital. This post first appeared at his blog at Forbes. His blog, which has been around in various forms since 2007, offers "musings on the intersection of science, medicine, and culture." His writing focuses on the difference between science-based medicine and "everything else," but also speaks to the day-to-day practice of medicine, fatherhood, and whatever else migrates from his head to his keyboard.