Vaccine expert Dr. Paul Offit is the author of the new book Deadly Choices: How the Anti-Vaccine Movement Threatens Us All. I talked with Dr. Offit about why you shouldn't have chickenpox parties, the realities of vaccine-preventable diseases, the importance of herd immunity, why it is unethical to run studies featuring vaccinated versus unvaccinated children, and just how extensively the autism-vaccine hypothesis has been debunked.
Dr. Offit discussed many of these same topics last night on The Colbert Report.
This interview is abridged. The full version was originally published at The Thinking Person's Guide to Autism.
What is your elevator pitch for parents concerned about vaccines and autism?
I think raising the concern is reasonable. Children get vaccines, and for some children, the signs and symptoms of autism may appear soon after receiving the vaccine, so asking those questions is reasonable.
The good news is that the question is answerable. Everything we know about autism tells you it's not the vaccines; why are we still focusing on this?
The anti-vaccination camp frequently demands to know why a vaccinated vs. vaccinated study hasn't been done. The reply is usually that such a study would be unethical.
You're right, [a vaccinated/unvaccinated study] is unethical. There's not an institutional review board in the world that would approve that kind of study, because we know that vaccines work, we know that if you don't give a large number of children vaccines that some of them are going to get whooping cough or chickenpox, some of them may be hospitalized or even killed by the diseases -- you can't do that kind of study.
People who believe their children's autism is vaccine-caused seem to mistake coincidence or correlation for causation. Can you give us an example of how that happens?
We're always looking for reasons why something happened. The example I use is from my wife, who is a pediatrician. She was about to vaccinate a four-month-old baby, and while she was drawing the vaccine from the syringe, the baby had a seizure -- and went onto have a permanent seizure disorder.
Now, my wife hadn't given the vaccine yet. But if she had given that vaccine five minutes earlier, there would have been no amount of statistical data in the world that would have convinced that mother that the vaccine hadn't caused the baby's seizure. You can do studies that show no increased risk with vaccines and seizure disorders, but that mother might still say "well, that's true for the population but it's not true for my child."
Temporal associations are powerful, and they're hard to defeat with statistics or studies.
Could you discuss the concept of herd immunity, specifically what it takes to establish it and protect public health?
Herd immunity simply means that you can stop the transmission of a virus or bacteria by having a critical number of the population immunized, and that number really depends on the nature of the virus or bacteria.
For example, Polio was introduced in the United States in 1955. When we got about 70 percent of the population immunized, that effectively eliminated polio, so it couldn't spread anymore. We eliminated polio from the U.S. by 1979.
Now, measles is much different, much more contagious than polio; you need a higher percentage of the population immunized. Overall the U.S. is in the high 80/low 90 percent immunization rate for measles, but there are certain communities where it's less than that, about 75 percent, and that's not good enough. When we had a measles outbreak in 2008, higher than anything we'd seen in a decade, it was in the communities with an erosion in vaccination rates -- Southern California, Upstate New York.
You also need to remember, there are about 500,000 people in the United States who can't be vaccinated, because they're getting chemotherapy for cancer, or are on immunosuppressant therapy for transplants or other disease. There are also kids younger than six months old who can't get the flu vaccine or are inadequately immunized against whooping cough because they're just starting their series. Herd immunity protects them.
People still hold chickenpox parties, and think of chickenpox as a mild childhood disease. But measles can be serious -- Roald Dahl's daughter Olivia died from measles encephalitis, and in your book you listed some rare but fairly gnarly potential measles side effects, including necrotizing fascitis. That's flesh-eating bacteria, isn't it?
*Shudder* Can you talk about the risks of vaccine injury versus the risks from contracting vaccine-preventable diseases?
The chickenpox vaccine is stabilized with porcine gelatin, and people can have a serious reaction to the gelatin, it's real but rare. But that pales in comparison to what chickenpox did before the vaccine: four million cases per year, 10,000 hospitalizations, between 70 and 100 would die.
Also, chickenpox lives silently in the body. It can reactivate later in life to cause shingles, it can reactivate early in life to cause strokes. We've seen a few children in my hospital with permanent paralysis from strokes caused by reactivated chickenpox. It's a bad disease, it's worth preventing.
A vaccine's benefits should always dramatically outweigh its risks, and I think for every current vaccine we use, that's true. With the oral polio vaccine, once we'd eliminated polio from this country, the vaccine's risks outweighed the benefits, and we switched to the inactivated vaccine.
Why did the government take over responsibility for vaccine injuries in this country?
Because we almost lost vaccines for American children.
In the early 1980s, there were people who had the false notion that the whole-cell pertussis (whooping cough) vaccine could cause brain damage. There was a tremendous amount of litigation claiming that the vaccine caused epilepsy, mental retardation, SIDS, unexplained coma. There were tens of millions of dollars in awards and settlements for what was not a very big business for the pharmaceutical companies, and they gradually started getting out -- until at one point we had only one company making whooping cough vaccine for children, and that company was about to get out.
Whooping cough killed about 8,000 people per year before we started vaccinating, so the government stepped in, to basically protect these vaccine makers from direct litigation. We created the National Childhood Vaccine Injury Act (NCVIA) in 1986, and it did just that.
Do you think part of the problem with vaccines backlash is that too few people in this country have first-hand experiences with vaccine-preventable diseases?
I think that's exactly it. My parents had no problem vaccinating their children because they knew exactly what these disease could do, same with me; I'm a child of the '50s, I had no problem vaccinating my kids either.
For young parents today, it's not just that they don't see them now, it's that they didn't grow up with these diseases. Vaccination becomes a matter of faith -- but faith in who? In the government, in the pharmaceutical companies? There's been an erosion in that kind of faith.
I spoke with (American Academy of Pediatrics spokesperson) Dr. Ari Brown during the 2010 pertussis epidemic; she said she sees people of grandparenting age disregard their personal experience in favor of what they see on Oprah and in the media. Have you seen this at all?
I think we're abnormally influenced by celebrity. People will seriously consider Jim Carrey, Jenny McCarthy, Bill Maher, or Larry King as a source of health information, and that's sad. It would be funny if it wasn't so dangerous.
In your book, you mentioned that vaccines made it easier for women to enter the workplace.
You can imagine, when measles and mumps and German measles -- all of which I had as a child -- were common, my mother was staying home with each of the three of us as each of us got the diseases. She spent a lot of time at home taking care of sick children. Vaccines have taken care of the fourteen main diseases that were causing a lot of illness and hospitalizations and death. There's still a lot of infections out there, but they're not quite as severe as the ones we've managed to prevent.
There has been a report that the current swine flu vaccine has been causing febrile seizures in some people. Could you talk about this, and clarify the difference between febrile and classic seizures?
First of all, it appears that it possibly may have been associated with an increased risk of seizures due to fever, but that's still to be determined. I wouldn't say that's solid yet.
There are about 150,000 children who suffer febrile seizures in this country; my daughter had a febrile seizures, actually, associated with the DTaP vaccine. They're hard to watch -- my daughter's was a grand mal seizure, it lasted for a couple of minutes, she was out of it for a couple of minutes.
The data are very clear -- febrile seizures don't cause sequelae, we know they're benign. Anything that causes fevers in a child less than two at risk for febrile seizures can cause febrile seizures. Ear infections can cause febrile seizures, colds can cause febrile seizures, not just vaccines. One shouldn't make more of this than it is.
Are vaccines constantly upgraded and monitored for safety and efficacy?
Yes, like no other medical product, including all the drugs you put into your body and certainly more than anything you'd get at the General Nutrition Center. We have a very well-tested, well-worn vaccine schedule.
What have vaccines done? They've helped us live decades longer than we did 100 years ago. There's so much good that's come from vaccines that it really hurts me to watch the way that people just dismiss them. We had five children [at my hospital] die from the novel H1N1 flu strain last year, none of them were vaccinated, all of them could have been saved by vaccinations. It's not OK. It's just not OK.
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