Monday, September 30, 2013

Paul Offit: "Science it's not about being open-minded"

by Felipe Nogueira

Interview with Paul Offit
Paul Offit is an pediatrician, the Chief of the Division of Infectious Diseases of the Children's Hospital of Philadelphia, and was the co-inventor of the rotavirus vaccine. He wrote books about the importance of vaccines, clarifying the risks, which is often misunderstood by people. In example, some people believe that MMR vaccine (against measles, mumps and rubella) causes autism. However, that relationship was already analyzed scientifically and we know it's wrong. 

His last book, Do You Believe in Magic? The Sense and Nonsense of Alternative Medicine, on which he makes a critical analysis of alternative medicine, was published this year.

I did an interview with him and it's available on Youtube. I thank Paul Offit for his time and attention. This is the first part of the interview. 

Links: second part | Youtube | versão em português

Can you pinpoint when the anti-vaccination movement started? 
I think it started with the first vaccine. The smallpox vaccine was developed by Edward Jenner in 1700s. There was violent opposition to the vaccine in the early 1800s and the reason was because that vaccine was mandated. People don't like to be told by the federal government they need to get a vaccine. That happened with the first vaccine and it's true today. If you talk to the professional anti-vaccine people, like National Vaccine Information Center, Moms Against Mercury, Safeminds, Generation Rescue, I think they will say they would stop their anti-vaccine efforts if you simply make vaccines optional.

What exactly is the risk of Guillain-Barré Syndrome with flu-shot? 
You can say with confidence that the swine flu vaccine that was given in 1976 had a risk of Guillain-Barré Syndrome in 1 per 100.000 who were given the vaccine. It is not clear that since then any vaccine causes Guillain-Barré Syndrome. But the limit of detection is 1 per million. CDC and other groups that tried to categorize this always say that we cannot say is more common than 1 per million. The people are left with this vague notion that vaccine might cause Guillain-Barré Syndrome, but since the 1976 swine flu vaccine there is no clear evidence that it has.

If a vaccine causes a problem, usually the disease that the vaccine try to prevent causes the same problem with higher risk for it. Can you elaborated on that?
The best example would be thrombocytopenia, which is lowering the platelets level. Measles vaccine can cause thrombocytopenia. There is a couple of studies and they all have been consistent and reproducible: the measles vaccine causes thrombocytopenia in 1 per 25-30 recipients. A measles virus also does that and it is far more common. When you get a chicken-pox vaccine, from 8 to 12 days after that, you can get a mild chicken-pox rash with 5 blisters, but sometimes can be 30 blisters. But if you get chicken-pox natural infection you can get 300 to 500 blisters.

Knowing that MMR vaccine does not cause autism, how do you think it is dangerous to widespread information not corroborated by science?
I wish I had the answer to that. I think once you scare people, it's hard to unscare them; once you open the Pandora’s box, it's hard to close it. When the question was raised by Andrew Wakefield in 1998 with his publication in the Lancet, that wasn't a study. That was a simply case series: 8 children whom had received the vaccine and developed symptoms of autism within 1 month. There are now 12 studies, looking to large number of people who did or didn't get the vaccine to answer the question "are you at a greater risk of having autism if you receive that vaccine?" The answer has been very reproducible: no. I think people are far more compelled by anecdote than they are by statistics. So, if Jenny McCarthy gets on Oprah and says "I watch my son get this vaccine, I watch his soul leave his eyes" and she cries, that's very compelling. If you have a scientist on the show that says "fair question: could the vaccine cause autism?  Is this a causal effect relationship? Is this just a temporal effect or it is a plausible effect?" You can answer that question. It's a scientific question, it can be answered in a scientific venue and it has been answered in a scientific venue. But how do you compel people with science? And how do you trump the anecdote with science? And the media became critical and they're not great at it.

What about your history with urologists, PSAs and prostate cancer? 
Yeah. I ended up switching urologists, because the urologists that I was seeing continuous to buy into the notion to get repeated PSA levels and repeated the biopsies. There is morbidity associated with that. And my think was to find a urologist who I though was practice medicine that was consistent with evidence that PSAs and biopsies haven't lengthened the lifespan of the american male. PSA and biopsies mean a lot of money for urologists and they make a living of this. It was nice to be able to find a urologist who was willing to practice medicine based on what was the evidence. I just saw a recent New English Journal article which look to people who took finasteride and compare them with people that didn't take finasteride. It found a lower incidence in people who take finasteride of having prostate cancer that was unlikely to kill you, the same type that causes high PSA levels, so called prostatic intraepithelial neoplasia type I and II. It's when you get to third stage [of cancer] that there is a problem. Because the urologists will continue to pursuit continuous PSAs and biopsies, finasteride avoid that, lowering your risk of going through that. In any case, it's a flawed system for all the biopsies and PSAs that were done: it hasn't lengthened the lifespan of the american male. But it's a big money maker for urologists, so I think they are slow to give it up.

What is your opinion about medicine students have been taught in medical schools things that are not scientific?
I think it's criminal. I got an email from a student who was at third year medical school in New York State University. He said he had a lecture from a homeopath that explains the water can remember that there was an active substance in some point of the past. Nonsense. He wrote a letter to dean of the medical school saying he is offended that this man came to teach him in a medical school that should be evidence based, not mystical. The dean wrote him back that he need to be more open minded. Very painful. This has nothing to do with being open-minded, it's all about evidence. Science it's not about being open-minded, it's about forming a hypothesis, establish burdens of proofs and subject those proofs to statistical analysis. Science has nothing to do with politics; it has nothing to do with being open-minded. I would think the dean of New York medical school would know that, but he didn't.

It could be said that the one who is not being open-minded is the dean of medicine, because he is not willing to accept homeopathy does not work. 
But maybe sometimes it does work. I mean, maybe sometimes you take something that you think is going to benefit you and it does benefit you simply because you think it's true. Placebo effect is not trivial, it's a real effect, and it can have a physiological base. I talk about that in the last chapter of my book. People can learn to release neuroendorphines and to regulate the immune system.

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