COVID-19 Vaccine Hesitancy: How Did We Get Here and What Do We Do Now?

Credit: SPH GH801 students.
COVID-19 Vaccine Hesitancy: How Did We Get Here and What Do We Do Now?
Last semester, SPH students in the course How to License a New Vaccine (GH801) explored the root causes of vaccine hesitancy in Africa. They present their findings, as well as strategies to increase vaccine uptake, in the paper below.
Authors: Christopher Gill, associate professor of global health, and GH801 students Madolyn Dauphinais, Michael Olaseni Bamgbose, Kelsey Flannery, Deena Afana, Josh Harvey, Andy Hui, Taylor Paiva, Elena Stratis, and Maria Tjilos. Special thanks to the entire Fall 2021 class of How to License a New Vaccine for their contributions.
Introduction
For the past nine years, I have taught an immersive course focused on vaccine development to my students at Boston University School of Public Health: How to License a New Vaccine (GH801). This course was based on my prior experience leading a vaccine clinical development team in industry, and the course touches on many of the fascinating aspects of vaccinology and clinical development that was my world during my three years at Novartis Vaccines and Diagnostics (now GSK).
Each year the course takes a new vaccine and/or a new focus. In 2021, our focus, naturally, was COVID vaccines—and, more specifically, how to better use existing licensed vaccines to increase supply, access, and utilization across the African continent. Within that larger course objective, I elected this year to have the students host a mini symposium focused on vaccine hesitancy. While hesitancy is distinct from the process of vaccine licensure, hesitancy was front and center in terms of its relevance to vaccine use post licensure. The four student working groups were given a topic to focus on, and some broad questions to get them started.
The four topics were:
1. The taxonomy of hesitancy.
2. The sources of hesitancy in Africa.
3. The role of social media in vaccine hesitancy.
4. Identifying the “anti-vaxxers” in Africa.
Each group presented a 15-minute overview of their topic, after which all groups combined in a brainstorming exercise to counter misinformation and reduce COVID vaccine hesitancy. I was so impressed with their creativity that I asked the students if they would be interested in disseminating this project to a larger audience. Their enthusiastic ‘yes’ is summarized in the four sections that each group provided below.
The taxonomy of vaccine hesitancy
Vaccine hesitancy is not a new phenomenon. Its origins can be traced back to 1796, when Edward Jenner’s smallpox vaccine was first developed. Although an impressive feat of modern medicine, it was initially met with protests and outrage. What most opponents did not recognize, however, was the beginning of one of the greatest public health achievements of all time—the eradication of smallpox. In the early 1900s, vaccines were brought back into the purview of skepticism with the case of Jacobson v. Massachusetts. In a question of personal liberty versus police power, the legal precedent to mandate vaccines in the United States was born. In the 1930s, polio outbreaks began to increase in frequency, and in 1954 Jonas Salk developed the long-awaited polio vaccine in the largest double-blind randomized control trial to date.
Between the 1950s-70s, vaccine acceptance became more favorable in the eyes of the public. This growing acceptance for vaccines took a turn with the release of the 1982 documentary DPT: Vaccine Roulette, a film where doctors and parents claimed that children developed permanent brain damage as a result of receiving the DPT vaccine despite no data supporting that claim. Unfounded fears and controversy continued to surround vaccines, albeit in mostly small groups, until a new, stronger wave of hesitancy was introduced following the publication of Andrew Wakefield’s illegitimate claims linking the MMR vaccine to autism in 1998. Its publication was accompanied by a significant drop in MMR vaccine coverage and can be considered the beginning of the modern anti-vaccination movement most of us are familiar with.
Key Definitions
Since the onset of the COVID-19 pandemic, terms such as vaccine acceptance, vaccine confidence, vaccine refusal, and vaccine hesitancy have been used colloquially and sometimes interchangeably. Breaking down the definitions of these terms will help contextualize attitudes towards vaccines at this crucial time when vaccination is one of our best tools to fight COVID-19.
● Vaccine acceptance is the decision to accept or refuse vaccination when presented with the choice to vaccinate. This is an umbrella term that ultimately includes vaccine hesitancy and refusal and is affected by the level of confidence individuals and groups have in vaccines.
● Vaccine Confidence—Combining definitions from the Centers for Disease and Prevention (CDC), US Department of Health and Human Services (HHS), and the World Health Organization (WHO), vaccine confidence is the overall trust in the efficacy of the vaccine, the systems in place to deliver and administer the vaccine such as health systems and providers, and the motivations of policymakers who recommend them.
● Vaccine refusal is the voluntary, conscious decision to decline an immunization. This choice can be driven by a variety of factors, such as the beliefs, concerns, or preferences that an individual or a particular group of individuals feels towards immunization. Sources of vaccine refusal include social groups and social media, along with other forms of media. It is important to note that not all those who refuse a vaccine have also experienced vaccine hesitancy, which demonstrates that one can refuse an immunization without expressing hesitancy.
● Vaccine hesitancy is the postponed decision to either receive or refuse an immunization, once immunization is readily available. Five aspects of vaccine hesitancy include confidence, complacency, convenience, calculation of risk, and collective responsibility, which are collectively referred to as “the five C’s.” Socioeconomic status, education, personal anecdotes, cultural background, and trust in the medical field and scientific community are factors that fuel vaccine hesitancy.

The above graphic shows how the terms vaccine acceptance, vaccine confidence, vaccine hesitancy, and vaccine refusal are related to each other. Attitudes towards vaccines can be visualized as a continuum, where refusal and acceptance sit at either end of the spectrum. The level of confidence an individual or group holds in a vaccine and the systems which develop and administer vaccines can affect overall attitudes towards vaccines.

In the Context of COVID-19
Since the start of the COVID-19 pandemic, the vaccines developed to tackle it have become a polarizing topic. A variety of factors have fueled an increase in COVID-19 vaccine hesitancy, including concerns about their effectiveness, potential side effects (immediate and long-term), and their rapid production and distribution. The use of social media greatly contributes to COVID-19 vaccine hesitancy, allowing for the increased propagation of misinformation and disinformation and conspiracy theories, leading to great mistrust in the scientific and medical communities. Additionally, confusion about how different COVID-19 vaccines work and the lack of consistent public health messaging have led many to feel hesitant about becoming vaccinated against COVID-19. This is not to mention other prominent factors that impact attitudes towards the COVID-19 vaccines, such as socioeconomic status, barriers to care, and structural racism, which continue to broadly perpetuate healthcare inequities.
What do we know about hesitancy in Africa?
Like many other countries, African nations were not immune to the skepticism of vaccines. The very same fears which began in Europe and the United States took root and spread throughout the continent. Fueled heavily by the MMR controversy, anti-vaccination sentiments carried on into the early 2000s, now spearheaded by Muslim clerics boycotting the oral polio vaccine in Nigeria. Decades later, these fears have never fully dissolved, and as such, their sentiments linger in the age of COVID-19.

Unfortunately, most research on vaccine hesitancy has only been conducted in high-income European and North American nations. Therefore, it would be irresponsible to extrapolate causes of vaccine hesitancy in Western nations to other countries and cultures around the world. Africa is a continent with historical precedent of vaccine hesitancy—hesitancy fueled by a lack of community involvement, adequate vaccine infrastructure, multisectoral collaboration, and routine immunization schedules acts as part of a robust one-health modality.
As such, we were interested in exploring causes of vaccine hesitancy across the African continent. We found that there is no standardized method of measuring the dynamics and complexities of vaccine hesitancy. Program managers in Africa tend to lack the guidance and tools to address quantitative and qualitative measures, a difficulty compounded by the lack of research on different social, cultural, and religious norms. Therefore, generalizations and assumptions cannot be made due to current gaps in information regarding the African continent.
When broadly discussing the needs of the African continent, it is paramount to remember that Africa consists of 54 unique countries and different cultural identities. Western perspectives of the continent may mistakenly regard Africa as a single region which can perpetuate harmful generalizations. Nations in Africa should be recognized for their vastly different environments, cultures, and backgrounds, all of which contribute to their views on vaccinations. As a result of historical and longstanding colonialism, Africa’s many different regional and national identities have been shaped from the languages spoken, foods eaten, religious and cultural practices, and mistrust of institutionalized and Western medicine.
The Role of Religion
Across the African continent, religious leaders hold great influence over their communities. Throughout recent history, there are many examples of religious leaders who have a significant impact on how their followers and communities view vaccines. In 2003, religious leaders in northern Nigeria boycotted the “Kick Polio Out of Africa” campaign launched by the World Health Organization (WHO). Recent studies in South Africa on vaccine hesitancy have found that a significant portion of those interviewed cite religious, cultural, and customary precedent as reasons not to get vaccinated, and they also believe prayer is a better defense against COVID-19. The Apostolic Christian community of Zimbabwe is vehemently against vaccines, Western medicine, and invasive medical care, instead opting for prayer, basic hygiene, and masks. This has resulted in some community members getting vaccinated in secret, out of fear of being publicly shamed and criticized, or even ostracized from their communities.
Overall, vaccine-hesitant religious leaders have expressed skepticism in orthodox healthcare and medicine, belief in government-sponsored population control, pure cynicism, belief that the vaccine contains antifertility agents, diseases such as HIV, and carcinogens, and an abundance of caution in the post-9/11 era for Western powers mingling in Muslim countries at a time when Western powers have fought against Muslim people in the Middle East. While these reasons listed are not exhaustive and not necessarily linked to religion, it represents a clear example of the influence religious leaders hold and shows the importance of their consideration as stakeholders.
Mistrust
Institutional trust plays an important role in gaining confidence in vaccines and their uptake. People are more likely to comply with vaccination programs when public trust exists in institutions such as the political system, healthcare system, and pharmaceutical industries. When trust in these institutions is low, vaccination rates decrease. In many parts of Africa, corruption has been cited as one of the main reasons for political distrust leading to boycotts of vaccination programs.
In addition, the colonial past and history of medical experimentation in Africa have increased the level of vaccine hesitancy. The unpleasant experience of the “Trovan trial” conducted by Pfizer in 1996 in Kano State, Nigeria during the meningococcal meningitis epidemic still lingers in the memory of community members and threatens to undermine COVID-19 vaccination in the region. More recently, the WHO’s handling of the 2014 Ebola outbreak has left a residual impact in those sub-Saharan African regions. The image of health workers in protective suits descending upon villages to isolate or remove the dead went against religious and cultural norms, resulting in broken trust and much disdain.
Safety & Side Effects
Concerns regarding vaccine safety, adverse events, and effectiveness are important determinants of vaccine hesitancy. Studies show a strong association between uptake of vaccine, and perceived vaccine safety and adverse events following vaccination. There were concerns regarding the safety and effectiveness of COVID-19 vaccines even amongst healthcare professionals across the continent. The initial suspension of AstraZeneca and Johnson & Johnson vaccine rollouts in South Africa, due to concern about variant effectiveness and blood clot development respectively, led to reduced confidence in these vaccines.
The role of social media in vaccine hesitancy
In the Era of COVID-19
In the last two years, we have learned that social media is a major driver of vaccine hesitancy. The COVID-19 pandemic intensified the use of social media, allowing us to remain connected while physically apart. The extended use of social media leads to increased exposure to misinformation and rumors about vaccination. Even brief exposure of 5-10 minutes can increase overall perception of vaccine risk. Moving forward, social media interventions are necessary to ensure uptake of new vaccines.
Misinformation & Disinformation
Vaccine disinformation and misinformation represent the main tools utilized to drive vaccine hesitancy across all platforms. Disinformation includes inaccurate information with malintent, while misinformation typically includes inaccurate information without deceitful intent. The sources of such information stem from North American and European networks building upon existing anti-vaccine messaging and pre-existing fears given historic unethical Western medical practices. These networks question Western financial and political motives, such as Bill Gates and World Health Organization, to reinforce conspiracy theories like the “New World Order” and targeted depopulation. Anti-vaccine supporters take advantage of the ability to simultaneously reach and influence large audiences through social media. A fifteen country study on vaccine perceptions investigated by the Africa CDC found individuals demonstrating higher levels of vaccine hesitancy and belief in disinformation are more inclined to seek online sources for information. Similarly, nearly half of the respondents reported seeing disinformation, and 59 percent note social media as the source. Anti-vaccine streams can capitalize on this widespread usage of social media to break down trust in actors and institutions involved with the COVID-19 vaccine and consequently push their agenda forward.
Social media plays an important role in the dissemination of health information. Individuals use various online platforms to seek health information and make decisions regarding their health. These online platforms also contributed to the rise in fringe opinions that harm public health. Vaccines are known to be very effective against several infectious diseases. However, conspiracy theories and misinformation about the effectiveness and safety of vaccines are being spread online. For years, MMR vaccines were reported across social media to have caused autism. However, this claim has been discredited.
The COVID-19 pandemic also witnessed various misinformation spreading across social media. These include the linkage of the virus to 5G technology, the COVID-19 vaccines being regarded as a depopulation plan, and the belief that COVID-19 vaccines contain antifertility agents. Many anti-vaccination websites are sponsored by organizations that have financial interests in discrediting vaccines. These websites often claim vaccines are ineffective while advertising/selling products that are not scientifically proven to be effective as alternatives to vaccines. The exposure to vaccine misinformation has impacted attitudes and perceptions towards vaccines resulting in the decline in vaccination rates.
Identifying the ‘anti-vaxxers’ in Africa
Although groups perpetuating vaccine misinformation may be few, they hold the unique ability to influence millions. Several political figureheads with massive followings have spread vaccine misinformation throughout the African continent, including presidents, governors, and supreme court justices. Their views can be particularly damaging, especially for concerned citizens seeking guidance during times of uncertainty. Healthcare workers, scorned by a lack of protection at the start of the pandemic, hold similar feelings of uncertainty. A lack of government action when it was most needed has left many wondering why they should be trusted now. Although there are many self-proclaimed “anti-vaxxers,” the number of originators of vaccine information is surprisingly small. Researchers at the Center for Countering Digital Hate (CCDH) traced anti-vaccine media back to its sources, finding nearly two-thirds of COVID vaccine disinformation beginning with 12 individuals. Although their anti-vaccine devotion may seem based on their own fears, there is likely more to the story. Considering that several of these individuals promote their own products in favor of the vaccines, they may have more to gain than originally thought.
The leaders of the vaccine hesitancy movement have various, but collective motivating factors, ranging from personal gains to religious, political, or moral beliefs. Religion in Africa is an important aspect of daily life for many. The Apostolic Church has cited doctors, medicines, and drugs as “anti-God.” Furthermore, Dr. Karanja, an influential leader in Kenya, has allied with religious leaders and opposed previous vaccines. Influential political leaders have stressed their vaccine hesitancy messages to the public to further their own agenda too. The former president of Tanzania, John Magufuli, might have been known for battling corruption, but was against the Western Nations and their vaccine pressure. All his efforts may have been for personal gain and to keep his image of being non-corruptive. Lastly, populism in politics has encouraged an “us” vs “them” society where leaders can identify with those against the vaccine; thus furthering their political stance too. The motivations facing the movement lie primarily in fear and mistrust in the structural system of the healthcare system, despite what the government may speak or act.
Acknowledging present conflicts of interest is a step towards understanding why hesitancy towards COVID-19 vaccines exists. Universally, healthcare workers strive to provide quality patient care. The more patients and hospital staff who are vaccinated, the less of a burden placed on the healthcare system. However, many healthcare workers may distrust the system and question the safety of the vaccines available to them. For political leaders, many previous COVID-19 conflicts of interest related to measures aimed at controlling the spread of the virus. Closing borders meant international trade would be harmed. Mask-wearing led to pushback from constituents and lockdowns injured businesses and income for many. In countries such as South Africa, populism is common. Data show that voters of the populism party had high rates of vaccine hesitancy. Members of religious groups, such as the Apostolic Church of Zimbabwe, believe many modern medicines are an insult to their faith. They seek to advance their religious messages, which may speak against the use of vaccines, instead promoting the use of alternative medicine.
Strategies to Counter Vaccine Hesitancy
Perhaps the greatest barrier to increasing vaccination rates is encouraging vaccine acceptance among the population. One major question we sought to answer was, is it better to incentivize vaccination or mandate it? A study conducted in Sweden, consisting of over 8,000 subjects, suggested that monetary incentives, even as low as $24 USD did increase vaccine uptake. However, although these results are promising, one study in the U.S. found monetary rewards to be ineffective in increasing vaccination rates. Other vaccine-encouraging tactics include employers offering paid-time off for vaccine appointments and recovery aligned with the American Rescue Plan tax credit incentive for employers. At least eighteen states offered unique incentives through contests or other financially-driven avenues to encourage people to get vaccinated. While incentives worked to increase vaccination intent, incentives do not act as a final policy solution that influences vaccination rates and addresses access issues. Other incentives have included vaccine passports, which have received major pushback in the U.S. given barriers to uptake and vaccine politicization. However, contrary to findings in the U.S., polling suggests that most European countries support this. In Italy, France, and Germany, proof of vaccination is needed to enter most public spaces such as restaurants, stadiums, and gyms.
On the other hand, many major companies in the U.S. are requiring employees to be vaccinated. These mandates vary by company, with some requiring the vaccine only for those working in person, while others are mandating it regardless of remote working status. To, including Austria, Ecuador, Indonesia, Micronesia, Tajikistan, and Turkmenistan. In many other countries, such as Canada, Croatia, and Egypt, these mandates are in place for federal employees. In the U.S., as mandates were ushered into hospitals, some healthcare workers protested, prompting walkouts.
Reluctance & Mandates
There are a few ideas concerning the primary reason people appear so reluctant to opt in to receiving COVID-19 vaccines. The cultural cognition theory states that individuals will gravitate to news and information sources supporting their current beliefs to fit their narrative. The vaccine-hesitant have the ability to consult a vast community of online support groups for reaffirmation when faced with information that falsifies their reality. The social identity theory supports the power of belonging as it relates to the self. In this theory, members of the “in-group” will seek to find negative aspects of the “out group” to strengthen their self-image. The choice to get vaccinated turns more into an issue of betraying one’s own group (such as the anti-vaccine community) rather than whether they are effective and beneficial to individual health. Using the COVID-19 vaccines as a case study, it becomes apparent that willingness to get vaccinated has become a partisan issue. This is highlighted by the individuals who have chosen to get vaccinated. Those who identify as Republican or Republican-leaning independents represent 41% of adults, yet these same individuals make up 60% of the adult unvaccinated population. This shows the power of the in-group out-group theory in influencing the decision to get vaccinated to remain “in” the group with your people.
Physician-Patient Relationship
When looking at effective strategies to combat vaccine hesitancy, it is essential to look at parental vaccine hesitancy and physician-parent relationships. Research shows that a physician recommendation is one of the most influential factors affecting vaccine uptake. This is because doctors are viewed as a trusted source of information, especially primary care providers (PCPs), who often have long standing relationships with patients. It is important to focus on children and individuals that are “under-immunized” instead of those who refuse all vaccines, as there is a greater likelihood of success in changing behaviors. To confidently change the minds of those that are vaccine hesitant, physicians need to build trust with parents, as facts alone may be insufficient. They must address all concerns thoroughly and be honest about side effects. Telling relevant stories is effective in reaching parents and it is important to focus on the benefits of protection.
Other strategies to target parental hesitancy include tailored messaging, such as materials specific to parents’ cultures, addressing specific vaccine-related concerns, and culturally competent information. Another strategy to employ could include consistent communication, with reminders from physicians via letters, postcards, and phone calls. Lastly, introducing greater parental empowerment, encouraging them to be vaccine advocates, educating their communities, and changing the social norms that surround them.
Tailoring Immunization Programmes (TIP)
The WHO Tailoring Immunization Programmes (TIP) offers guidance to design interventions which combat low vaccination rates. The main goal of TIP is to identify and characterize populations with low vaccine uptake and identify behavior barriers and motivators to receiving vaccinations in these situationally dependent contexts. It provides a social science approach that promotes the development of strategies tailored to both areas, focusing on how vaccine services are promoted and delivered. Community stakeholder engagement is crucial from the beginning to build relationships and trust. This can happen by conducting focus groups, key informant interviews, and community stakeholder interviews/workshops of those in a specific community to gain understanding of vaccine behaviors and reluctance. The strength of TIP includes its interdisciplinary approach and the ability of programmes to gain important understanding of community and individual perspectives.
Development of Digital Health Strategies
A commitment to structural changes is needed to counter anti-vaccine content on the world’s biggest social media platforms. Facebook uses algorithms to hide anti-vaxx pages, Instagram omits anti-vaxx hashtags, and Twitter links vaccine-related words to Vaccines.gov. Loss-frame messaging can be used to optimize behavior change by framing messages in terms of “losses” rather than “gains.” For example, loss-frame messages about HPV vaccination increased perceived severity and intent to change among college students. Leveraging social media platforms can allow for healthcare providers to utilize personal platforms to communicate directly with patients. Additionally, fostering social media and government agency relationships to spread information. Another avenue is the use of celebrity or influential figures to promote vaccine uptake. Politicians and celebrities have a massive influence on social media and this influence can be used to motivate the public in favor of COVID vaccination.
Is vaccine hesitancy irrational?
In the era of COVID-19, when vaccines are one of the major tools we must fight the pandemic, many question whether vaccine hesitancy is irrational. There have been a variety of events that have directly contributed to the fears, mistrust, and hesitancy surrounding immunization and the intentions of the medical system. For example, in the Tuskegee syphilis study, researchers left nearly 400 Black men untreated to understand the progression of syphilis. Not only was the experiment itself a tragic example where researchers failed to protect the Black community, but the wrongdoings committed by researchers fueled rumors of purposeful infection, which unfortunately still stand today. Events such as this, in addition to previous vaccine failures and the misrepresentation of data in the popular media, instilled mistrust in the scientific and medical communities.
Given the history of vaccine hesitancy and the previous failures of the medical community to provide equitable care across communities, a degree of vaccine hesitancy can be entirely rational. As we continue battling the COVID-19 pandemic, it is crucial to affirm the feelings and experiences of those who feel hesitant, rather than impose judgment. There are many reasons why individuals may be hesitant- our priority is not to judge, but to listen.
Community mobilization may be an effective strategy in rebuilding trust in healthcare institutions and promoting vaccine uptake. The participation of community influencers such as religious leaders and traditional rulers in vaccination campaign programs can promote trust and increase confidence in vaccines. Social media influencers can be employed to promote vaccines on their various platforms. Healthcare professionals should provide evidence-based information to the public. Access to adequate information regarding vaccine safety and side effects can help reduce vaccine hesitancy and increase vaccine trust which would eventually increase vaccine acceptance.
Discussion & Conclusion
Africa is a vast continent, and no sweeping generalizations or recommendations can be made that will fully address the needs of all its countries and republics. However, by tackling vaccine disinformation at its root, there is hope that pro-vaccine sentiments will be able to spread and promote public health knowledge for millions. While it may be shocking how common vaccine hesitancy is across Africa, it becomes less so when examining its dark history of colonialism and imperialism, and how these practices have destroyed African trust for Western countries. Although claims of forced sterilization and intentional harm may be unfounded, it is not unreasonable to see where their fears originated.
Rebuilding the trust in medicine that is needed to promote efficient vaccine uptake is a daunting task. If there were a clear answer, there would be no need for discussion. After a thorough analysis of vaccine hesitancy, we propose the following measures:
- Tailored social media use, which not only protects users from harmful mis- and disinformation, but also promotes accurate public health messagery.
- Encouraging community engagement and mobilization, lending itself to enhanced outreach and improved health literacy, all while satisfying the specific needs of the communities.
- Taking an anti-judgment stance to hesitancy, allowing for improved conversation and idea exchange without enforcing paternalism.
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