In the short video that follows, Dr. Offit explains why the HPV vaccine is not a cause of chronic diseases.
News Briefs — HPV Vaccine and Chronic Diseases
Dr. Paul Offit: Hi, my name is Paul Offit, I’m talking to you today from the Vaccine Education Center at the Children's Hospital of Philadelphia.
What I thought I’d talk about today is the human papillomavirus or HPV vaccine. Now, this is a vaccine that was first recommended for all teenage girls in 2006 in the United States. By 2010, four years later, it was recommended for all teenage boys again 11-13 years of age, and the reason is HPV, most importantly of all, is a cause of cancer. It causes head and neck cancers. It causes anal and genital cancers. It causes cervical cancer. And so every year in the United States, there’s about 27,000 cases of cancer caused by HPV and there are 5,000 deaths caused by HPV. The vaccine will prevent about 85 percent of that, 85 percent of those cancers, about two-thirds of which occurs in girls and women and about one-third of which occurs in boys and men. Yet still, despite that we are now 10 years into this vaccine for girls and more than five years for boys, only about 45 percent of girls get this vaccine and only 20-25 percent of boys get this vaccine. Why? What seems to be the hang-up? Why isn’t it that people are getting a vaccine that clearly prevents cancer?
I think there are a number of reasons for that, but one of them I think are some ill-founded concerns about vaccine safety. People are worried that the HPV vaccine might be causing chronic problems like chronic pain syndromes or chronic fatigue syndromes or autoimmune syndromes when you’re body reacts against itself.
Now, this vaccine has been the most studied, the most extensively studied vaccine post-licensure, ever. It’s been formally studied in more than a million people, and it’s been shown not to cause any of the side effects that people were worried about. Specifically, the autoimmune diseases, which I think has gotten the most media attention. So, let me explain why it is not only that we’ve shown it hasn’t, but why it doesn’t make sense that it would have caused those problems. In order for your body to react against itself, it needs to see a protein on the surface of the cell as foreign. So, for example, people who have Type 1 diabetes, their immune system will actually react against the cells that make insulin in their pancreas. They see those cells as foreign. Now, is it possible for a vaccine or infection to actually trigger an autoimmune response? And the answer to that question is, it’s possible, but in order for it to happen there has to be something called molecular mimicry, which is to say that there is a protein in that vaccine that mimics a protein on the surface of your cells. So infections do this all the time. So for example, strep, the kind of strep that causes a sore throat can cause rheumatic fever, that’s an autoimmune disease, because there is a protein in the bacteria strep, so-called group-A strep, that mimics a protein that lines the surface of your heart. So while you’re making an immune response to group-A strep, the kind of strep that causes strep throat, you also can make an immune response to your heart and cause rheumatic fever. Similarly, the Lyme bacteria can cause a long-lived arthritis, which it to say inflammation of joints, because there is a protein on Lyme bacteria, the so-called outer-surface protein A, or OspA protein, that actually mimics a host protein, a protein in your own body. So, that can happen. When you’re responding to a bacteria, in these cases strep and Lyme, you actually can also be responding to yourself. So the question then for human papillomavirus becomes is there a protein in human papillomavirus that mimics a host protein. Well you know that natural infection with human papillomavirus doesn’t cause an autoimmune response. And because natural infection, where the virus reproduces itself thousands of times, is going to be a much great challenge to your body than the vaccine, which consists of just a single protein from nine different strains of the virus, in fact doesn’t reproduce itself at all, is much less likely to do something that’s occurring with natural infection. So now you know that the human papillomavirus itself, the wild-type virus, the natural virus, doesn’t cause autoimmunity, therefore it doesn’t make sense that the vaccine would cause autoimmunity. Plus, you know the HPV vaccine doesn’t mimic any sort of protein that exists in the human body, so it doesn’t make sense that it would have ever caused a problem.
So I think people can be reassured the HPV vaccine is safe. We certainly know that it’s effective, and a choice not to get it is only a choice to put your child at unnecessary risk of cancer later in life, which is an unconscionable choice.
Related Centers and Programs: Vaccine Education Center