By FELICIA D. GOODRUM STERLING, PhD and HEIDI L. POTTINGER, DrPH, MPH, MA

The measles outbreak in Washington state this week has brought new attention to the anti-vaccine movement.  In fact, the World Health Organization recently identified “vaccine hesitancy” as one of top threats to global health. In the US, the number of unvaccinated children has quadrupled since 2001, enabling the resurgence of infectious diseases long-since controlled.  In fact, the WHO claims a staggering 1.5 million deaths could be prevented worldwide by improved vaccination rates.

Amidst the media and public health outcry, a mystery persists:  Why has vaccine hesitancy continued, despite years of vigorous debunking of shoddy science?  The answer may lie in a deeply-rooted distrust of doctors and science.

One of the authors of this article, Dr. Pottinger, surveyed hundreds of Arizona parents, from schools with exemption rates greater than 10%, about their perceptions on vaccines. Pottinger and colleagues found the vast majority of the parents surveyed who delayed or chose not to vaccinate their children did so because of true personal beliefs and not convenience.  Specifically, they tended to distrust physicians and information about vaccines or held misperceptions about health and disease, including the idea that immunity by natural infection is more effective or that vaccine-preventable diseases are not severe.

These beliefs, stoked by a fraudulent 2010 study, have proven almost impossible to shake—despite the fact that the debunked study, based on 12 children, was retracted due to serious ethical violations and scientific misrepresentation; authors cherry-picked and fabricated data, and the first author had undisclosed business interests in the vaccine industry.

The failure of many interventions to dispel misinformation demonstrates the power of a complex interaction of confirmation bias, cognitive dissonance, distrust in data sources, and personal experiences and narratives.  Taking them on requires that the healthcare community effectively spread the following messages.

1. Vaccine-preventable diseases are serious and life-threatening.

Before the first measles vaccine was introduced in 1963, 6,000 measles-related deaths were reported annually in the US. Furthermore, the vaccine protects against a rare but fatal degenerative disease (subacute sclerosing panencephalitis) that can occur 7-10 years after having measles. The incidence of measles fell precipitously after the vaccine was introduced and by 2000, was declared eliminated from the US. This is just one example. Currently, vaccines protect children against 14 different diseases that most people in the US can hardly remember.

2. “Natural” immunity from infection is not a solution

Natural infection carries a much greater risk than approved vaccines. Chicken pox is often considered a benign childhood infection; however, tens of thousands of people were hospitalized every year and hundreds of people died prior to the release of the chicken pox vaccine in 1995. Further, contracting chicken pox as a child creates the risk for shingles or zoster as an older adult. Flu, too, is often accepted as a normal part of winter, but in 2018, 900,000 hospitalizations and 80,000 deaths were attributed to influenza. The re-emergence of measles results in preventable illness and death even years after infection. Vaccines are more targeted – with immune loads just a fraction of those used decades ago. In fact, the antigen and adjuvant load in vaccines does not compare to what children encounter naturally every day.

3. Vaccines are effective

The measles vaccination program effectively eliminated measles from the U.S. Yet, vaccine hesitancy has allowed the re-emergence of measles and less protection against infections that are ever present. Less than half the population gets flu shots, but we know that it reduces risk by as much as 60 percent in the overall population.  Vaccine rates for human papilloma virus (HPV) are similarly low, despite the fact that vaccination could eliminate cervical cancer altogether if widely utilized.

4. Vaccines are safe and do not cause autism

While vaccines do carry a small risk of side effects—generally non-threatening inflammatory or allergic responses—vaccination is uneventful for the vast majority and clinical trials have shown these risks are far outweighed by the benefits. Millions have been safely vaccinated with the measles or MMR vaccine since the 1960s. Scores of subsequent rigorous, scientific studies conducted worldwide have definitively shown no causative link between vaccines and autism. Even the Chief Scientific Officer for Autism Speaks urges that “all children be fully vaccinated” – their facts and figures page clearly stating “Vaccines do not cause autism”.

5. Vaccines are more important than ever

With the widespread movement of people between countries and continents, vaccination is more important than ever, to protect vulnerable, unimmunized populations including immunocompromised individuals, infants, pregnant women, and the elderly – and to prevent outbreaks.

6. You have a role in ending vaccine hesitancy

With anti-vaccination misinformation so deeply entrenched, we cannot leave it only to health professionals to promote vaccines.  The first and most important thing you can do is vaccinate yourself and your children. Protect newborns or immune-compromised persons in your care from coming into contact with unvaccinated individuals. If your provider forgets to offer the flu (or any) vaccine, especially if you are pregnant – ask for it.

You can also help share the truth about vaccines. If you encounter vaccine-hesitant individuals, listen respectfully and share the scientific consensus on immunization. Rather than dismissing their concerns, try to acknowledge them and connect them with information and stories they may find persuasive to effectively communicate your concerns. Lastly, remind your friends and neighbors we are all in this together, and must each do our part to reach immunity thresholds that keep vaccine-preventable diseases under control, and stop diseases from impacting the most vulnerable in our communities.

Dr. Felicia Goodrum Sterling is a professor and scientist at the University of Arizona who has studied viruses for 27 years. Dr. Heidi L. Pottinger is a public health researcher at the University of Arizona who has studied vaccinology, vaccine exemption, and topics related to children with special health care needs for 16 years. Both are Fellows of The OpEd Project.