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Dispelling a Big Myth About Childhood Vaccinations

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If you’ve ever been the subject of a rumor that was later proven false but by then had taken on a life of its own, you’ll understand the challenge pediatricians face when it comes to the issue of vaccine safety.

For nearly 20 years, many parents of young children have been wringing their hands over a highly publicized study that supposedly linked the MMR vaccine—which covers mumps, measles and rubella (German measles)—with a higher risk for autism or other developmental issues in children. Although the study’s conclusions were proven utterly false, the original story persists.

It all began in 1998, when British physician Andrew Wakefield and 12 colleagues suggested the vaccine/autism link in a case report published in the British medical journal Lancet. Almost immediately, other studies began proving there was absolutely no significant connection between the two.

For unexplainable reasons, however, the rumor spread, playing on the worst fears of parents—even after the United Kingdom’s general medical council concluded in January 2010 that Wakefield and his team had not only been wrong but were guilty of dishonest and misleading conduct. Wakefield lost his medical license as a result of his unethical behavior.

On a more personal and local level, two of my practice partners have been pediatricians for more than 40 years each and can verify from personal experience the safety and effectiveness of childhood vaccinations, including the MMR vaccine. In their time as physicians, they’ve witnessed how vaccines have stamped out many dangerous childhood diseases. As a result, we have no reservations whatsoever about recommending the full panel of childhood vaccinations to parents who come to us for care.

In spite of all of this evidence to the contrary, however, there are still parents who worry about even the slightest possibility of long-term negative health effects from vaccines. Many of them choose to rely on “herd immunity”—the idea that, since most parents have their children immunized, their unvaccinated children will be less likely to be exposed to viruses.

There are some dangerous problems with this viewpoint. First, in order to even have a hope of herd immunity, at least 96 percent of the population must be vaccinated. It’s virtually impossible for parents to know what percentage of the children their kids come into contact with have been vaccinated. Second, this approach puts babies who are too young to be vaccinated at even greater risk of exposure from unvaccinated children. The result is frightening: A potential resurgence of some of the devastating childhood diseases that have been nearly wiped out in our country.

There was a prime example of the failure of herd immunity right in our own backyard in late 2014. An outbreak of measles that spread to 145 people in seven U.S. states, as well as others in Canada and Mexico, was traced back to Disneyland. A sick child or children exposed others to the virus, who then took it home with them and, most likely, passed along the disease.

Undoubtedly, a large percentage of unvaccinated children contributed to this outbreak. In fact, infectious disease experts who studied the incident concluded that as few as 50 percent of the children exposed at Disneyland may have been vaccinated. Even at the study’s high-end estimate, only 86 percent were vaccinated—well below the 96 percent threshold for herd immunity. The conclusion: It’s never a safe bet to rely on the hope that others around you have been vaccinated.

While the vast majority of pediatricians strongly support childhood vaccination, that doesn’t mean parents have no say in the process. Your pediatrician will no doubt be happy to answer any questions you have and discuss your concerns about immunization.

For instance, some parents don’t want their children to have all of the recommended shots on the same day. In that case, my office has an altered immunization schedule that spreads the shots out over a few weeks. We also offer a catch-up immunization plan for parents who have changed their mind about having their child vaccinated.

To learn more about immunization safety, recommendations, schedules and much more, check out the extremely informative website of the Centers for Disease Control and Prevention, cdc.gov/vaccines.

Lauren Tashman, MD, is a board-certified pediatrician with Simi Pediatric Partners in Simi Valley and is a member of the Simi Valley Hospital medical staff.