Emily Paulsen

July 28, 2011

July 28, 2011 (Washington, DC) — Vaccines protect both the individual and the community, yet a significant number of parents decide not to vaccinate their children, placing them at risk of contracting dangerous diseases and potentially exposing others to those diseases through a loss of herd immunity.

"Vaccines have made a tremendous impact on the health of children," said Daniel Salmon, PhD, MPH, director of vaccine safety at the National Vaccine Program Office of the US Department of Health and Human Services in Washington, DC.

Dr. Salmon spoke at a special Pediatrics Immunization Update here at the National Medical Association (NMA) 2011 Annual Convention and Scientific Assembly. "Vaccinations are a public health intervention," he stated. "Immunization providers have an important role in working with parents who are vaccine-hesitant."

Vaccination programs have led to 93% to 100% elimination of many childhood diseases in the United States. Right now, Dr. Salmon pointed out, the incidence of childhood diseases that vaccines protect against is lower than the unscreened reports of adverse events — meaning that parents might be more familiar with the arguments against vaccination than they are with the risks of not vaccinating their children.

Laws requiring vaccinations are made at the state level, and all states require vaccination for school and/or daycare attendance. But all states also allow some exemptions to the vaccination law for medical, religious, and/or philosophic reasons, and 67% of states do not deny exemptions.

Although the nationwide rate of parental refusal to vaccinate their children is low, about 10% of parents refuse or delay at least 1 vaccination in the recommended schedule, and there are some areas of the country where as many as 1 in 4 children have not been vaccinated.

Dr. Salmon showed a map of Colorado with a direct overlap between counties with higher rates of vaccine refusal and outbreaks of pertussis, a childhood disease that has seen a resurgence in recent years. The map indicates that vaccine refusal might play a role in these outbreaks.

Paul Offit, MD, director of the Vaccine Education Center and chief of the division of infectious diseases at the Children's Hospital of Philadelphia, Pennsylvania, traces the upswing in vaccine refusal to the 1998 paper published by Andrew Wakefield, a British gastroenterologist, in the Lancet. Although that study has been refuted time and again, and even called "an elaborate fraud" in BMJ, myths about the standard childhood vaccination schedule persist.

Dr. Offit told the NMA audience a "tale of a shifting hypothesis," which started with a reported link between autism and the measles, mumps, and rubella (MMR) vaccine, and then moved to suspicions about the mercury-containing preservative thimerosal, and the "immune system overload theory."

Although all of these theories have been rebutted, parents are still concerned, Dr. Offit said, especially about autism. Many parents have heard stories about children who develop signs of autism soon after vaccination, but this is likely because the MMR vaccine is normally administered around the typical age of onset of autism symptoms.

"We have no other explanation for autism," he said. Other diseases like sickle cell can be explained by genetics. Autism has a genetic basis, but that doesn't explain it all. "Vaccines are an easy, simple, straightforward answer that just happens to be wrong."

It is understandable that parents continue to fear vaccines — they do, after all, often result in crying babies — but providers must do what they can to counteract those fears.

"It's important to try to understand the parents' concerns and what influences them," said Dr. Salmon. In 2005, nearly 70% of parents who did not vaccinate their children cited safety concerns as their reason for refusal. Other reasons cited included fear of overloading the immune system and belief that the child was not at risk for the disease or that the disease was not dangerous.

Even parents who vaccinate children harbor fears about the process, Dr. Salmon said. A report published in the June 2011 issue of Health Affairs showed that just 23% report no concerns about the process. The others reported concerns similar to those who did not vaccinate, including pain, too many vaccines in one visit, fever, and learning disabilities (such as autism).

"We can do a better job of presenting the choice and risks involved," said Dr. Offit. Many physicians modify the schedule to help parents feel more comfortable, but Dr. Offit wonders about the wisdom of this. "It's hard to watch kids get a lot of shots at one time, but more frequent visits may actually result in more pain." He also points out that delaying vaccination exposes the child to more risk of contracting the disease.

Parents might actually react more favorably when physicians open an honest dialog and state their case that vaccination is best for the child and for the community.

Although studies convince physicians, Dr. Salmon points out it might be more effective to tell actual patient stories about the safety and effectiveness of vaccines. "We may practice evidence-based medicine, but most parents are motivated by anecdotes," Dr. Salmon said.

Dr. Salmon has disclosed no relevant financial relationships. Dr. Offit is the coinventor of the RotaTeq vaccine but receives no financial remuneration for sales of the vaccine from either the manufacturer or his employing institution.

National Medical Association (NMA) 2011 Annual Convention and Scientific Assembly. Presented July 27, 2011.


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