Study Finds Disturbing Trends in Vaccination Exemptions

Rising Rates of Nonmedical Exemptions Could Hike Vulnerability to Disease Outbreaks

June 20, 2018, 02:34 pm Michael Devitt – (Editor's note: Following the publication of a correction to the first study cited in this story, Pittsburgh has been removed from a list of areas with large numbers of kindergarteners who have nonmedical vaccination exemptions.)

A new study shows that numerous states and large metropolitan centers have seen an uptick in the number of nonmedical exemptions (NMEs) from childhood vaccinations granted. The study, published in PLOS Medicine, found that in the past decade, the number of philosophical exemptions to vaccination has increased in two-thirds of the states that allow such exemptions. As a result, researchers suggest that these areas are becoming increasingly vulnerable to vaccine-preventable disease outbreaks.

Many State, County NME Rates on the Rise

The researchers found "an overall upward trend" in the number of kindergarteners with NMEs in 12 states that offer philosophical exemptions. Yearly analysis indicated that the average NME rate in each of these states increased the most between 2009 and 2014. Whereas NME rates reached a plateau in some states in the past three years, rates have continued to rise in others.

At the county level, Idaho had eight of the 10 highest NME rates of all states in the study group. Camas County, the second least populous county in the state, had the highest rate, with nearly 27 percent of kindergarteners having a documented NME. Utah's Morgan County was 10th, with a rate of almost 15 percent.

In addition to the states with higher NME rates, the researchers found a number of metropolitan areas with large numbers of kindergarteners with NMEs. Metropolitan areas with populations of more than 1 million people that had high NME numbers included

• Detroit;
  
• Houston;
  
• Kansas City, Mo.;
  
• Phoenix;
  
• Portland, Ore.;
  
• Salt Lake City; and
  
• Seattle.

"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 researchers wrote.

Complicating matters is the fact that each of these cities has at least one international airport, which the researchers suggested could increase the risk of a disease outbreak spreading beyond the United States.

Higher NME Rates = Lower Vaccination Rates

Evidence has repeatedly demonstrated the effectiveness of vaccines in reducing the incidence of infectious diseases such as measles. For example, a retrospective cohort study published in JAMA showed that a child who received the measles, mumps, and rubella (MMR) vaccine is about 35 times less likely to contract measles than a child with an NME for that vaccine.

Evidence also has shown that NMEs reduce herd immunity to such diseases. Although the vaccination coverage rate required to achieve herd immunity varies based on the infectious agent, it typically must be between 80 percent and 95 percent to be considered effective.

To determine the influence of NMEs on vaccine uptake, the researchers compared MMR vaccination rates and NME rates in states in which those data were available, using information from the 2016-2017 school year. They found "a significant inverse association" between the two. Overall, states with more students with NMEs had lower MMR vaccination rates, while the states that had no NMEs (California, Mississippi and West Virginia) demonstrated the highest MMR vaccine uptake and the lowest incidence of vaccine-preventable diseases.

Policy Changes Effective in Reducing Exemptions

In 2000, public health officials declared that measles had been officially "eliminated" in the United States. Yet recent high-profile measles outbreaks in California, Minnesota, Ohio and other states show the effect low vaccination rates can have on the resurgence of some vaccine-preventable diseases.

To address these issues at the state level, the study authors suggested that legislation that would prohibit philosophical NMEs or require parents to watch an educational module before obtaining an NME might serve as an effective intervention. They noted that California law allowed for philosophical exemptions to vaccines at the time of a well-publicized 2014 measles outbreak at Disneyland. In 2015, the state legislature enacted a law that banned both religious and philosophical exemptions. As a result, the state's kindergarten vaccination rates reached an all-time high during the 2016-2017 school year, and the number of kindergarteners with documented NMEs dropped to its lowest level in more than a decade.

"Given the effectiveness of closing the exemption policy, evidence suggests that other states should consider discontinuing the NME option and protect schoolchildren from vaccine-preventable diseases," the authors wrote.

Family Physicians Offer Their Perspectives

With 18 states allowing philosophical exemptions, and all but three states allowing NMEs for philosophical or religious reasons, family physicians are likely to encounter patients who object to being vaccinated themselves or to having their children vaccinated. How can FPs best educate patients who have concerns about vaccines or do not want to vaccinate their children, and how do they address patients who request an NME on religious or philosophical grounds?

AAFP News reached out to several family physicians for their answers to these questions. Jennifer Frost, M.D., medical director for the Academy's Health of the Public and Science Division, recounted similar experiences with parents who chose not to have their children vaccinated. "When addressing these families, it is important to remember that they are doing what they believe is best for their children," she said. "I was always open about my strong support for vaccination and shared the facts about safety and efficacy. But I did it in a nonjudgmental way, ultimately respecting their choice. This allowed me to keep the dialogue open so that we could continue to discuss the issue."

Parents who express concern about vaccines may have received false or misleading information, which can be difficult to counter. Frost's advice in these situations? "Keep it as simple and objective as possible. And remain respectful. When you feel passionately about the benefits of immunizations, it can be challenging to listen to parents deny their children protection based on inaccurate information. But if parents feel judged, they will not be open to information and may go elsewhere for care."

And, as Frost related to AAFP News, change does not occur overnight. It can take several appointments and discussions, and even then, there is no guarantee that patients will change their minds. "While most families did not change their stance, I did have a few successes," Frost said. "But these occurred only after multiple visits and conversations."

Douglas Campos-Outcalt, M.D., M.P.A, a clinical professor at the University of Arizona College of Medicine and a former voting member of the CDC's Advisory Committee on Immunization Practices (ACIP), told AAFP News that vaccines "have been one of the most effective public health interventions of all time." He said that if he encountered a patient who was hesitant about vaccines, "I would first ask what their concerns are and then address them head-on. I would tell them about the seriousness of the infections being prevented, assure them that vaccines are safe, tell them I vaccinate all of my family members, and refer them to trustworthy materials to read."

Like the others, AAFP liaison to the ACIP Pamela Rockwell, D.O., of Ann Arbor, Mich., has encountered her share of parents who do not want to vaccinate their children. "I approach these parents by acknowledging that I understand that they are trying to care for their children in the best way they know how with the information they have at hand," Rockwell told AAFP News. "I present them with accurate, evidence-based information that shows that vaccines are safe and prevent disease. I discuss the dangers of contracting some of the preventable diseases and potential bad outcomes that may ensue when these diseases that most parents today have no experience with or knowledge of affect a child. I also dispel the myth that there exists 'natural immunity' to vaccine-preventable diseases or that one can build a strong enough immune system by healthy eating and healthy living to stave off infection if one is exposed to a communicable disease."

To provide further assurance, Rockwell lets parents know that her own children have been vaccinated with all of the recommended vaccines. She explains that vaccines are constantly being re-evaluated and studied to ensure that they are as safe as possible. And she even repeats the oft-quoted statement from CNN medical correspondent Sanjay Gupta, M.D., that a person is 100 times more likely to be struck by lightning than to have a serious allergic reaction to the measles vaccine.

But Rockwell has also drawn a hard line when it comes to NMEs.

"A few years ago, if patients listened to my advice and still wanted an exemption, I told them that for ethical reasons, I could not in good conscience grant a vaccine exemption for nonmedical reasons and I did not sign these waivers," she said.

In December 2014, Michigan's Joint Committee on Administrative Rules adopted new requirements for parents who wanted to opt out of having their children vaccinated. As a result, parents/guardians seeking an NME for their children in Michigan now are required to contact their county health department to receive education on immunization waivers and to obtain a certified state immunization waiver form. A waiver form is considered certified if it displays the county health department stamp and the signatures of both the authorizing agent completing the immunization education and the parent/guardian.

Resources Available

Given the shifting landscape regarding NMEs and the number of outbreaks of measles and other vaccine-preventable diseases in recent years, it is important for family physicians to remain up-to-date about the immunization laws in their state. The Academy's Immunizations Registry is one resource FPs can use for this purpose. Among other things, the registry contains an interactive immunizations map, as well as links to the AAFP's policy on vaccine exemptions and research on the effect of NMEs on vaccination rates.

Other available resources include the Shots app, a tool developed by the AAFP and the Society of Teachers of Family Medicine, and American Family Physician's AFP by Topic collection on immunizations.  

Additional Resources
Nonmedical Exemptions From School Immunization Requirements: A Systematic Review