Vaccine hesitancy and the spread of information: How Michigan can prevent disease outbreaks

In March of 2019, after an unknowingly infected traveler stopped in Michigan, there was an outbreak of 44 measles cases, with 40 of these cases centralized in one Oakland County community. Patients ranged in age from eight months to 63 years, with the outbreak largely affecting one underimmunized, close-knit community. While thankfully, no one died, the outbreak represents a growing trend and threat to the public health of Michigan.

Studies show that when vaccines are properly administered, such outbreaks are almost entirely preventable. However, the majority of those affected were voluntarily unvaccinated, or what is referred to by health professionals as being ‘vaccine hesitant’; those that choose to remain unvaccinated despite access and availability. While vaccine hesitancy is a growing trend — with a growing range of opposing opinions — studies show that refusing to vaccinate presents a clear risk to public safety, here in Michigan and across the world.

Vaccine hesitancy, or a voluntary and nonmedical aversion to vaccines, can trace its history as far back as the earliest vaccines, but there is a renewed movement that continues to pose a risk to public health. The modern reasons for abstaining vary widely. For many vaccine-adverse, their reasons are simply and purely personal, philosophical, or religious. Many others argue against vaccines by citing debunked and discredited misconceptions surrounding exaggerated adverse effects, misconstrued details of vaccine ingredients, and a well-refuted link to autism

While there is a minute risk for an adverse reaction to any administered vaccine, all medicines carry with them a risk of reaction, and the risk of serious reaction is incredibly low, estimated by health officials to be a one-in-a-million chance. While the risks of vaccines are demonstrably low, health experts agree remaining unvaccinated creates a risk to public safety. Vaccines currently prevent between 2-3 million deaths a year, but as Mary Wisinski the Immunization Program Supervisor at the Kent County Health Department, says, “If we continue to refuse [vaccines], these diseases are making a come back.” Essentially, according to Wisinski and other medical health professionals, if vaccine hesitancy is not addressed properly, outbreaks like the one in Oakland County will become more common. 

Mary WisinskiWisinski is a registered nurse and Kent County health official who oversees the County’s efforts to maintain what is referred to as “herd immunity.” When dealing with highly contagious and preventable diseases, like measles, mumps, and whooping cough, vaccines are critical to maintaining this “herd” or community immunity. The level of vaccination coverage needed to achieve this immunity varies by disease, but typically requires majority coverage as high as 80 or 90 percent. Once achieved, this herd immunity protects those who cannot build immunity from vaccines by preventing transmission.

The more people that are vaccinated, the harder the disease is to spread to the unvaccinated. This creates a shared responsibility to help maintain the community immunity otherwise, as Wisinski says, “We are failing those who cannot be vaccinated.”

Eventually, when enough people are vaccinated, the transmission of the disease can be almost entirely prevented and a disease is considered “‘eliminated,” a status defined as the absence of continuous disease transmission for greater than 12 months. However, community immunity and the so called “elimination” of these diseases is not indefinite in a globalized world, as unvaccinated travelers moving between communities can reintroduce diseases where they had been thought to have been eliminated. And when a community that has not retained its herd immunity due to vaccine hesitancy is exposed, outbreaks are more likely. As vaccine uptake rates continue to fall and pockets of under-immunized communities develop, the risk of future outbreaks continues to grow. 

When discussing the effectiveness of vaccines and the current trend of vaccine hesitancy, Wisinski says we are “Victims of our own success.” Vaccines prevent and eliminate diseases so effectively that over time, many forget what vaccines do to protect the health of a community. Smallpox is a prime example of what makes vaccines so important. One of the world’s deadliest diseases, killing more than 300 million people in the 20th century alone, was eliminated globally in 1977, all because of vaccines.

Most people living today didn’t experience what it was like to live before vaccines for serious conditions, like Polio or Measles, which now seem easily preventable or even nonthreatening. But most of these diseases have not gone away and can, once again, become serious public health issues when herd immunity is compromised.

Vaccines are stored at the Kent County Health Department to be used to help protect the health of Kent County residents.Measles is a clear example of this risk, as global measles deaths may have decreased overall by 80 percent since 2000, but in 2017 there was a 30 percent spike in global cases. A spike that many, like the World Health Organization, consider to be caused in large part by under-vaccination and vaccine hesitancy. 

Health officials like Wisinski see the recent US outbreaks as wholly preventable given that we now have safe and effective vaccines. “There is no reason for it,” she says. According to leading health experts, the most consistent factor in the resurgence of vaccine preventable diseases, like measles or hepatitis A, is vaccine hesitancy. This hesitancy, according to health officials like Wisinski, most often grows out of misconceptions and misunderstandings that create fear for the vaccine, but fail to recognize the danger of the disease the vaccine prevents. Getting vaccinated, according to Wisinski, is a part of the “Responsibility to society beyond oneself.” It must be done to protect the health of the community. Yet the problem of vaccine hesitancy has grown so much that in 2019 the World Health Organization listed it as one of the top ten greatest risks to public health.

Dr. Joneigh KhaldunDr. Joneigh Khaldun is the Chief Medical Executive and Chief Deputy Director for Health at the Michigan Department of Health and Human Services, and agrees with the World Health Organization that vaccine hesitancy is a risk to public health. Dr. Khaldun, who gives cabinet-level medical guidance and direction to the governor of Michigan, expresses deep concern about the dropping vaccination uptake rates and the rise of vaccine hesitancy, saying, “Vaccines are one of the most important tools we have in our public health toolbox. They’re safe, effective, and protect the health of our citizens.”

However, according to the Michigan Department of Health and Human Services, despite the importance and demonstrated safety of vaccines, this year in Michigan only 59.1 percent of children ages 19 to 36 months were up to date on all recommended vaccinations. The most recent data ranks Michigan 29th in the nation for vaccination coverage. Thankfully, given Michigan’s population density, a major outbreak is less likely than in other places. However, the 2019 outbreak in Oakland County shows any under-vaccinated communities are potentially at risk. 

The Oakland County outbreak was the largest outbreak of measles in Michigan since 1991, and was part of a larger national outbreak affecting pockets of under-vaccinated communities across the country. This outbreak coincides with others reported in California, Illinois, Texas, Washington, and was tied to the major outbreak in New York that resulted in 934 cases. From January 1 through October 1, 2019, there were 22 measles outbreaks and a total of 1,249 measles cases, the highest number of reported cases in the US since 1992. Vaccine-hesitant and close-knit communities accounted for 85 percent of all of these US cases. Measles, which had been declared eliminated in this country in 2000, is now on the rise again in the US in large part due to vaccine hesitancy. The combined increased global measles activity and the growing existence of under-vaccinated communities place the US at continual risk for future outbreaks.
 
When speaking of the resurgence of vaccine-preventable diseases, Dr. Khaldun, says she is “Concerned about the possibility of an outbreak” for Michigan residents. This comes after the third year in a row in which Michigan has shown an increase in unvaccinated students. While the number of unvaccinated students dropped significantly after the state issued a new requirement for parents to receive health department education in order to submit vaccination waivers in 2014, it has increased every year since. From 3.1 percent in 2015 to 3.8 percent in 2018, Michigan has seen a steady increase in unvaccinated students for three years. According to data from the Michigan Department of Health and Human Services, in some schools more than 25 percent of the students checked were not vaccinated and half of the state’s private schools surveyed had unvaccinated rates of 5 percent or more. When considering that diseases like measles need a high vaccination rate to maintain herd immunity, the potential for outbreak is present. As communities begin to grow more vaccine-hesitant, the risk of outbreak grows, too. 
 
According to health experts like Dr. Khaldun, the most important thing a citizen can do to prevent the spread of communicable diseases, aside from being vaccinated themselves, is to spread the facts. “We can speak up when we see misinformation,” says Dr. Khaldun. Health officials like her reassure the public that vaccines are safe, effective, and remain a vital tool for maintaining public health.
 
As Mary Wisinski at the KCHD emphasizes, every citizen has a responsibility to maintain public health, to protect those who cannot be immunized by vaccines. It is up to the public at large, Khaldun says, “to separate people’s opinions and misinformation from science fact.”

Photos by Adam Bird of Bird + Bird Studio.

This article is part of a three-part series on vaccination and the public health in West Michigan sponsored by the Kent County Health Department. Articles and their content are journalistically independent of and not reviewed by the KCHD. For reliable and evidence-based scientific information on communicable diseases and immunization in Michigan, visit the Michigan Department of Health and Human Services.
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