Vaccination Exemptions Rise in California Amid Concerns

Nancy A. Melville

November 03, 2011

November 3, 2011 (Washington, DC) — Increasing rates of unvaccinated young children with "personal belief exemptions" from vaccination requirements are becoming worrisome, according to research presented here at the American Public Health Association (APHA) 139th Annual Meeting.

Recent concern about vaccine safety appears to be gaining strength, and state regulations requiring parents to vaccinate their children before they can attend public schools vary. In California, obtaining a personal belief exemption could not be easier — parents are only required to sign their name to a 2-sentence standard exemption statement on the back of the vaccination requirement form.

In evaluating data on the rates of exemptions from the California Department of Public Health, the state's Department of Education and the US Census, researchers found that in 2010, the state had about 11,500 kindergartners with personal belief exemptions, representing a 25% increase over the previous 2 years.

The increasing rate indicates that, for kindergartners who have adhered to vaccination schedules, exposure to children with personal belief exemptions is about 2.3 per 100 children.

Because children with the exemptions tend to be found in clusters, the rate of children with exemptions who are exposed to other children who also have exemptions — a higher-risk combination — was 15.6 per 100 in 2010, said lead author Alison Buttenheim, PhD, MBA, from the University of Pennsylvania's Robert Wood Johnson Health & Society Scholars Program in Philadelphia.

"The average kindergartner with a personal belief exemption attends a school where the exemption rate is 15 per 100, and we see that figure increasing all the time," she reported.

Previous data from the fall of 2008 showed that 10% of the nearly half-million kindergartners in California attended schools where personal belief exemption rates exceeded 5%, and as many as 61% of kindergartners with 1 or more personal belief exemptions (n = 9196) attended schools where the personal exemption rate exceeded 5%. Among those, a third attended schools where the personal belief exemption rate exceeded 20%.

In a separate study conducted by the same team, the researchers investigated the concerns that parents have about vaccines by evaluating data on the specific vaccines received by 168 patients at a pediatric practice in Philadelphia where the practitioner, though pro-vaccine, is known to accommodate parents who seek alternative vaccination options.

Although not necessarily indicative of the larger population, the results give a snapshot of the types of issues that may underlie vaccination concerns.

The results indicated that as many as 40% of parents had more than one concern.

The leading concern was that the vaccines "overtax" the immune system (16%). "This was commonly expressed as the parents feeling the schedule just represented too many shots that could overburden the system," Dr. Buttenheim said.

Other reasons for concern included the rarity of vaccine-preventable diseases (10%), a preference for natural immunity (7%), and autism (5%).

Dr. Buttenheim noted that increasing rates of personal belief exemptions have coincided with sharp increases in measles cases.

"Measles cases were very low in the US until 2008, when rates jumped up. Things calmed down again but then they jumped up again in 2010. We are very close to 200 cases in the US this year.... Meanwhile, this a disease that we thought we had eradicated," she said.

Dr. Buttenheim underscored the need for public health officials and educators to come up with strategies to improve vaccination adherence rates and focus on epidemiologic "hot spots" where personal belief exemption rates are higher.

"Currently, the only thing parents need to do to get a personal belief exemption in California is sign their name on the back of the form and fill in the date," she said. "What we would like to do is make the exemptions a little harder [to get] and adhering to the vaccination schedule a little easier."

Some strategies could include imposing stricter requirements for receiving exemptions, training school nurses to communicate with parents the need to keep adherence rates up, or even somehow rewarding schools that keep adherence rates up.

"I don't know if this has even been tried yet, but one idea is to somehow bonus schools, even in a minor way, for keeping their vaccine exemption rates as low as possible," Dr. Buttenheim offered.

Wiley Jenkins, PhD, from the Southern Illinois University School of Medicine's Department of Family and Community Medicine in Springfield and moderator of the session, said he was not aware of any particular interventions that have been successful in increasing parent compliance with childhood vaccinations.

Dr. Jenkins added that he is not surprised that the rates are a concern in California, considering how little is required to obtain an exemption.

"Given the ease of obtaining a personal belief exemption in California, and also the multiple and local vocal opposition to vaccinations, I am not personally surprised at the findings," he said.

Whether the findings reflect broader trends around the country is not clear, he added. "It's very difficult to say as obtaining personal belief exemptions varies considerably," Dr. Jenkins said. "I think we have seen a general increase in parents either refusing vaccinations, limiting them, or spacing them out more."

"And we have observed an increase in some vaccine-preventable illness among children, such as measles. However, I do not think the presented relatively high rates in California are generalizable to the rest of the US."

"I think it does show how personal belief exemptions are a growing problem in California, how exposure is becoming even more common for those vaccinated, and that the increase and distribution of personal belief exemptions among children is a significant public health issue," Dr. Jenkins asserted.

The study received funding from the Robert Wood Johnson Foundation Health & Society Scholars program. Dr. Buttenheim and Dr. Jenkins have disclosed no relevant financial relationships.

American Public Health Association (APHA) 139th Annual Meeting; Abstracts #244895 and #244410. Presented October 31, 2011.


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