MELISSA BLOCK, HOST:
Vaccine proponents notched a win in California today. The State Senate Education Committee passed a bill that would require schoolchildren to be vaccinated. It would eliminate exemptions for the parents' personal or religious beliefs. The bill was delayed earlier after loud protest from vaccine opponents. One of the strongest centers of vaccine opposition is affluent Marin County, north of San Francisco. Dr. Matthew Willis is trying to change minds there. He is the public health officer for Marin County, and he joins us now from San Rafael. Welcome to the program.
MATTHEW WILLIS: Thank you.
BLOCK: And what is the percentage of unvaccinated kids in Marin County?
WILLIS: In Marin County, we have a personal belief exemption rate from required childhood vaccinations of about 6.5 percent, and that's a 20 percent improvement over two years ago, when our rate was 7.8 percent.
BLOCK: So it's better than it was before, but you would like to see that rate come way down.
WILLIS: Absolutely. And what's particularly concerning is that we have, in some schools, more than half of the children are unvaccinated.
BLOCK: Let me see if I understand the bill that passed the State Senate Committee today. As I understand it, it says that unvaccinated kids would have home schooling or independent study options. They couldn't attend public or private schools unless there's a medical reason that they couldn't be vaccinated. Is that how it works?
WILLIS: That's right. This new law would require that the only children who are allowed to be exempt from required childhood vaccinations are those that would have medical exemptions - that is those students who couldn't be vaccinated for medical reason - either documented allergy to a vaccine or an immune state that would prevent them from being vaccinated.
BLOCK: When you talk to parents about their fears about vaccines, how many of them specifically mention perceived risk of autism from the composition of what's in the vaccines?
WILLIS: Well, we performed a survey of our parents in Marin County to determine what their beliefs were when they opt out of required childhood vaccinations. And what we learned in that survey was that about one-third of our parents who are choosing the personal belief exemption cited a concern that there may be a relationship between autism and vaccinations.
BLOCK: Were you surprised to find it that high?
WILLIS: I was. I think, you know, we have one of the more highly-educated communities in the state of California. The study that first suggested there may be a relationship between autism and vaccinations in 1998 was famously falsified and retracted. And there's been dozens of studies since then that have shown that there's no correlation between vaccinations and autism. But I think one of the things we're learning is that once a doubt is introduced into the public's mind, it's difficult to pull back.
BLOCK: If you are trying to have a conversation with a parent who wants to opt out - doesn't want their kids to be vaccinated, what do you tell them? What's most persuasive?
WILLIS: I think one of the big missing pieces here historically in this dialogue has been the understanding that choice to opt out of vaccination is really a choice to opt out of shared responsibility for community welfare. We're trying to help parents understand that the choice to vaccinate their children not only protects their own children and their own family, but everyone else in that community - their friends, their neighbors, their classmates.
BLOCK: And how does that go? Does that seem to get through?
WILLIS: I think it's changing the dialogue a little bit. Parents are responding differently, especially in the context of the measles outbreak that's occurred over the last year. You know, a lot of this is based on risk-benefit. Parents had a perception that the diseases that these vaccines prevent are rare. If there's even a small perception of the risk of the vaccine and there's near-zero perception of the risk of the disease that the vaccine prevents against, they may choose not to vaccinate. The fact that we've had increased incidence of pertussis - that is whooping cough - and measles over the past couple years has, I think, changed people's perceptions of the risk of the diseases themselves. So we're seeing more parents who are choosing to opt in now.
BLOCK: Dr. Willis, thanks so much for talking with us.
WILLIS: Thank you very much.
BLOCK: That's Dr. Matt Willis. He's the public health officer for Marin County, Calif. Transcript provided by NPR, Copyright NPR.