by Edward Chen

Historical evidence shows that developing safe vaccines is necessary to protect the world from deadly diseases. But that’s only one part of the solution. After all, what’s the benefit of having vaccines that people don’t want to use? Enter vaccine hesitancy.

Defined by a World Health Organization (WHO) working group as a “delay in acceptance or refusal of vaccination despite availability of vaccination services,” vaccine hesitancy has increasingly entered the news alongside discussions of the COVID-19 pandemic. Despite the quick development of a COVID-19 vaccine, its widespread acceptance is still a concern. In May of this year, Gallup reported that 32% of adults worldwide would not be willing to receive a free COVID-19 vaccine. This is equivalent to 1.3 billion people globally and represents a barrier to achieving herd immunity, where a disease will be unlikely to spread because many in a population have gained immunity from either being vaccinated or surviving the disease. Within the US, a Kaiser Family Foundation survey this May found that 32% of adults are either taking a “wait and see” approach to vaccinations or already plan to not get vaccinated. Vaccinations have slowed since early April and 55% of Americans are worried about those around them not getting vaccinated.

The concept of vaccine hesitancy predates COVID-19 and has existed for as long as there have been vaccines. In 2019, the WHO listed vaccine hesitancy among the top 10 threats to global health because it “threatens to reverse progress made in tackling vaccine-preventable diseases.” When vaccinations slow down, rare diseases can flare up again. For example, the COVID-19 pandemic has interrupted mass immunization operations against many diseases worldwide, and this has caused a rise in cases of diseases like polio, even in countries where these diseases are no longer common. Even before COVID-19, the California Disneyland measles outbreak that started in late 2014 led to over 300 cases. Many who were infected were not vaccinated or didn’t know whether they were vaccinated, and at least 12 of those infected were infants under a year old who were too young to have received the measles vaccines yet. (This also illustrates the importance of herd immunity: some people are medically unable to be vaccinated.)

There are varied reasons for vaccine hesitancy. The WHO working group has cited the degree of trust in vaccines, healthcare systems, and policy makers (confidence),a perception of low risks from disease (complacency, which paradoxically arises because effective vaccines lead to low disease risk in the first place), and access challenges (convenience) as reasons for vaccine hesitancy. A survey conducted by Carnegie Mellon University and the University of Maryland in a collaboration with Facebook collected 18 million responses and found that 70% of vaccine-hesitant adults are worried about potential side effects of COVID-19 vaccines. Surveys from the Centers for Disease Control and Prevention (CDC) have identified other factors beyond safety, such as reliance on a “wait and see” approach, a lack of trust in the government, and concerns about the speed at which COVID-19 vaccines were developed.

In the US, vaccine hesitancy has often been attributed as the reason for lower vaccination rates in communities of color. The Tuskegee syphilis study, a racist experiment that denied African Americans effective medication for syphilis, is often cited as the cause of vaccine hesitancy and a general mistrust of the health system among African Americans. But this mistrust is also fostered by ongoing discrimination against people of color in the health care system and other barriers that limit their access, like the relative lack of medical clinics in non-white communities. Racial disparities in health care have been further highlighted and exacerbated by COVID-19: American Indian, African American, and Hispanic or Latino individuals have died of COVID-19 at twice the rate of white people. Vaccination coverage disparities have been observed between different ethnic groups and between communities with different socioeconomic statuses.

New policies have tried to address vaccine hesitancy by making vaccination a condition for other services. In 2015, after the measles outbreak at Disneyland, California eliminated vaccine exemptions based on personal, religious, or philosophical beliefs for children entering school. The result was an approximately 4% increase in vaccination rates among kindergarteners. According to a 2020 research article published in the Journal of the American Medical Association (JAMA), 51% of pediatric practices turn away families who refuse CDC-recommended vaccines for their children, citing the possibility that unvaccinated children may spread infectious diseases to other patients who haven’t yet been vaccinated. While this successfully persuades some parents, some physicians disagree with this policy because it can harm children by denying primary care and prevent physicians from further engaging with vaccine-hesitant parents. During the COVID-19 pandemic, various companies and states have been offering incentives such as gift cards and raffles. The CDC’s updated guidelines, which allow those who have been fully vaccinated to participate in many activities without masks or physical distancing, have also been described as an incentive for getting vaccinated.

As COVID-19 vaccination rates slow, some health care providers are taking on vaccine hesitancy face-to-face. Dr. Joseph Betancourt is a physician and the Senior Vice President of Equity and Community Health at Massachusetts General Hospital. He says that it’s a “big mistake” to only consider vaccine hesitancy when many more factors influence vaccination rates: lack of supply, misinformation, barriers to culturally competent care. In response to these obstacles, he personally visits communities to talk to people about vaccines as part of an institutional outreach effort involving 140 caregivers (mostly doctors and nurses of color). It’s their hope that engaging with healthcare workers who speak the same languages as and look like the populations they serve will help increase people’s confidence in the vaccines.


For more about how the COVID-19 vaccines were developed, watch our interview with a scientist working on the Johnson & Johnson vaccine.

This interview with Dr. Joseph Betancourt, a physician and the Senior Vice President of Equity and Community Health at Massachusetts General Hospital, was conducted on April 13, 2021.

Edward Chen is a first-year Immunology MMSc student at Harvard Medical School. He’d like to share that wearing masks in public is not a new concept either; during the 1918 influenza pandemic, the Red Cross called those who avoided masks “dangerous slackers.”

Cover image by Arek Socha from Pixabay.

One thought on “Vaccine hesitancy: More than a pandemic

  1. There is so much natural herd immunity already. Natural immunity is not only the the strongest but also the safest for everyone not in that over 60-65 bracket with preexisting conditions. VEARS stats are obviously not representing real stats if 7 elderly near me have passed since the mRNA jab and many injured. If my senario is usual, then that alludes to possibly much less then 5% is reflected.

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