The number of Marin parents choosing not to vaccinate their children when they enter kindergarten is continuing to grow, despite the best efforts of local public health officials to educate the community about the dangers of opting out.
State law requires that children entering school for the first time be vaccinated for a number of diseases: chicken pox, whooping cough, tetanus, polio, measles, mumps, German measles, hepatitis B, and haemophilus influenza type B, known as HIB, which can cause meningitis.
California, however, is also one of about 20 states that has a loophole in its vaccination law: the personal belief exemption. By signing a waiver that acknowledges their children may be kept out of school during disease outbreaks, parents may opt out of any and all immunizations.
Personal belief exemption rates statewide had remained fairly stable at about half of 1 percent for many years until the late 1990s, when a now-discredited report linked childhood immunization to autism. Since then, the rate has been rising steadily, reaching 2.79 percent statewide in 2012-13.
Here in Marin, the personal belief exemption rate has nearly doubled from 4.2 percent in 2005 to 7.83 percent in 2012-13.
And the rate is much higher than that at some Marin schools. At The New Village School in Sausalito, 14 of the 19 students entering kindergarten in 2012-13, 74 percent, exercised the personal belief exemption. That same year at the Greenwood School in Mill Valley, 14 of 21 incoming kindergartners, 67 percent, used the personal belief exemption. And at San Geronimo Valley Elementary in 2012-13, 13 of 29 kindergartners, 45 percent, avoided vaccinations using the personal belief exemption. Officials at the schools declined to comment.
"What is concerning about that is it starts approaching the rate at which we have less protection from what we call herd immunity," said Dr. Matt Willis, Marin County's public health officer. If a high percentage of a community has not been vaccinated -- about 80 percent to 94 percent -- then when a virus or bacteria arrives it can spread more easily because it finds more susceptible hosts.
Willis said in July three Marin residents were exposed to measles on an intercontinental flight from Germany.
"Fortunately, all three of those people were vaccinated against measles and none of them became ill," Willis said. "There were other people who were not vaccinated on that flight who did contract measles, so when they returned to their communities they were bringing measles to their friends and neighbors and classmates."
Last year, Dr. Nelson Branco, a pediatrician with offices in Greenbrae and Novato, began requiring that all patients age 2 and older be immunized with the measles, mumps, rubella vaccine. Branco said it was the year of the World Cup and the London Olympics, and he was particularly concerned about travelers bringing the disease back to Marin.
"We did not want to be spreading measles to an infant in our waiting room," Branco said.
In 2010, California experienced a whooping cough (pertussis) epidemic, the worst since 1947. Over 9,000 Californians contracted the disease, hundreds of people were hospitalized, and 10 babies died. That year at least 350 Marin residents fell ill with pertussis, more than in the past 10 years combined.
"After that, I think there was an increased awareness from parents who may before have been resistant to having their children immunized," said Carol Essick, a recently retired health project manager at the Marin County Office of Education.
It was following the pertussis outbreak in 2010 that the Marin Immunization Coalition formed to try to stem the rising tide of personal belief exemptions. Sharayn Forkel, the county of Marin's immunization coordinator, and Dr. David Witt, an infectious disease specialist at Kaiser Permanente Medical Center in San Rafael, serve as co-chairs of the coalition.
Despite the coalition's best efforts to get the word out that vaccines are safe and that passing them up puts the health of the entire community at risk, the number of parents using the personal belief exemption in Marin has continued to climb.
Forkel said many parents remain worried that vaccines will cause autism despite a mountain of medical evidence refuting the idea.
"There is a lot of press; but I'm not sure everyone has gotten the word yet," Forkel said.
Dr. Witt said, "There is a huge amount of bad information out there. When you search on the Internet you get bad information popping up first. It's hard to refute false anecdotes and accusations."
Forkel pointed to a film screened at the Fairfax Women's Club in March as an example of some of the potent misinformation being disseminated. The film was "The Greater Good," which purports to document "personal stories of vaccine tragedies."
Public health officials are also concerned that celebrity Jenny McCarthy will soon have a bigger megaphone. McCarthy, who will become a co-host of the morning TV talk show, "The View," in September, has repeatedly claimed that vaccines played a major role in giving her son autism.
Witt said, "As one of our pediatricians says to his patients who choose to refuse vaccines, 'I'll work with you on this; but you'll have to agree: if you get your medical advice from Jenny McCarthy, you'll have to get your fashion advice from me.'"
In January, a new state law, AB2109, takes effect, requiring parents who want to use the personal belief exemption to consult with a health care practitioner first.
Witt said the new state law will make a difference for some people, who are several generations removed from the deadly disease outbreaks of the past and mistakenly fear that a vaccine will make their child autistic.
Witt said, however, for some rational arguments from their physicians will likely fall on deaf ears.
"There are people who are disbelievers, and I don't think information is going to change them," Witt said. "For them, it's an issue of faith."
Contact Richard Halstead via e-mail at firstname.lastname@example.org