Anti-Vaxxers Make Kids This Arizona County Vulnerable: Study

MARICOPA COUNTY, AZ — Certain cities are more vulnerable to diseases that can be prevented by vaccines because of a growing number of vaccine exemptions being given for non-medical reasons, according to a new study. Vaccine exemptions on the basis of philosophical beliefs have risen in 12 of the 18 states where they are offered, and certain “hotspots” stand out in states with an unusually large number of exemptions.

Arizona offers vaccine exemptions for non-medical reasons and Maricopa County has allowed more than any other regional in the country. Texas also has several hotspots.

The study found that in states with higher overall vaccine exemptions, fewer children are vaccinated against mumps, measles and rubella. Of the 18 states that offer exemptions based on philosophical or religious beliefs, known as a non-medical exemption, 12 states had an overall upward trend since 2009 for the enrollment of kindergartners who haven’t been vaccinated against the common childhood diseases, according to the study.

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The states with the upward trend are:

• Arkansas
• Arizona
• Idaho
• Maine
• Minnesota
• Missouri
• North Dakota
• Ohio
• Oklahoma
• Oregon
• Texas
• Utah

In Maricopa County, 2,947 non-medical exemptions, or NMEs, were granted for vaccines in the 2016-2017 school year. For the sake of comparison, the lowest number of such waivers in the hotspot areas was Spokane, Washington, with 405.

“The high numbers of NMEs in these densely populated urban centers suggest that outbreaks of vaccine-preventable diseases could either originate from or spread rapidly throughout these populations of unimmunized, unprotected children,” the study says. “The fact that the largest count of vaccine-exempt pediatric populations originate in large cities with busy international airports may further contribute to this risk.”

NMEs weaken “herd immunity” — that is, immunity that occurs when large populations are vaccinated — and that leaves children who can’t be vaccinated for medical reasons especially vulnerable. According to the study, the target vaccination rate to achieve ideal herd immunity is 90 to 95 percent.

Despite the high number of exemptions in Maricopa County, the vaccination rate for MMR among the 83,627 kindergartners in our state in the 2016-2017 school year was 94 percent, which is above the target rate.

The authors said the study is limited in its ability to correlate outbreaks with communities where there are high NMEs, so subsequent studies will be critical.

The study notes that strict policy changes have led to decreases in rates of exemptions granted for non-medical reasons and points to California’s ban on NMEs after a measles outbreak started in Disneyland. After the ban, the number of non-medical exemptions in the 2016-17 school year dropped to the lowest level in California in a decade, according to the study.

“Although many states demonstrate rising exemption totals irrespective of the exemption policy, states that make it harder to obtain exemptions have demonstrated slower-growing opt-out rates over time,” the study says. “Therefore, it is critical to identify states at highest risk for an outbreak due to a rise in NMEs.”

The study recommends that policy changes should be accompanied with efforts to increase access to vaccines, educational programs and awareness campaigns. The study says an approach with a central emphasis on discontinuing NMEs will work to increase vaccination rates.

Rising NMEs linked to the anti-vaccine movement in the U.S. could stimulate other countries, especially low and middle-income countries, to follow a similar path, the authors write.

Photo via Shutterstock / New Africa