>> Hi, my name's 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 to 13 years of age.
And the reason is, is that HPV more important ... most importantly of all is a cause of cancer.
It causes head and neck cancer.
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% of that, 85% of those cancers, about two-thirds of which
occurs in girls and women, and about one-third of which occur in boys and men.
Yet still, despite that we now are 10 years into this vaccine for girls and more than
five years for boys, only about 45% of girls get this vaccine, and only 20 to 25% of boys
get this vaccine.
Why? What seems to be the hang-up?
Why isn't that people aren't 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
syndrome, or chronic fatigue syndromes, or autoimmune syndromes, when your
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 that 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 on
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 an infection to actually trigger an autoimmune response?
And the answer to that question is, it's possible.
But it order for it to happen, it actually ... 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 immune response to group A strep, 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 is 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 greater challenge to your body than the vaccine, which is a ... 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 that 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 peo ple can be reassured that 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.
Thank you