After the COVID-19 pandemic hit, the rapidly-developed vaccines were hailed as the best way to defeat the virus. Most people were keen to get vaccinated as soon as possible. However, some declined it or decided to wait. Medical News Today investigates the history of vaccine hesitancy and speaks to experts and individuals on both sides of the vaccine debate.

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Why are people hesitant about COVID-19 vaccines, and how can experts tackle this issue? Image credit: Bettmann/Getty Images.

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Vaccination is one of the greatest success stories of modern medicine. Smallpox is now a distant memory, wiped out by a comprehensive vaccination program, and polio is on the way to joining it in the realms of history.

But it was not always like this. Infancy used to be a time of peril, with many carried off by communicable diseases before their fifth birthday. In the United States, almost half of all babies born in 1800 would not reach the age of 5. By 2020, that figure had dropped to just 7 in 1,000. Thanks largely to vaccination, the risk of death from infections continues to decline.

According to the World Health Organization (WHO), before COVID-19, only two communicable diseases — lower respiratory tract infections and diarrheal diseases — were in the top 10 global causes of death. The other eight were noncommunicable, with ischemic heart disease at the top.

So why are some people reluctant to accept vaccinations? A look back in history may give us some answers.

Smallpox was a scourge of humankind for centuries, killing some 30% of those who caught it and disfiguring or blinding many who survived. Then, in 1796, a doctor in the United Kingdom, Edward Jenner, made a discovery.

People who had contracted cowpox, a milder disease, appeared immune to smallpox infection. From this observation came the first smallpox vaccine.

Dr. Jenner’s methods would certainly not pass modern medical regulators. He injected fluid from cowpox (“vacca” is the Latin word for cow) lesions into a neighbor’s 8-year-old son, giving him the disease. A few weeks later, he injected him with smallpox. The boy did not become ill.

Vaccination for smallpox was far more effective and safer than previous attempts at giving immunity by inoculating people with fluid from smallpox lesions. This practice, variolation, gave the inoculated person a milder illness. However, it also led to deaths and outbreaks of smallpox.

Vaccination was not without its problems. Poor hygiene practices at the time meant there was a very real risk of blood poisoning and cross-infection. Syphilis was passed on by vaccinating babies with congenital syphilis before vaccinating other children. And it has been claimed that the spread of syphilis during the American Civil War was partly a result of contamination during smallpox vaccination.

These risks, and the downplaying of them by some pro-vaccinationists, triggered mistrust in the vaccine in many individuals. Some modern-day opponents of vaccination cite the hiding of adverse effects as a reason for their opposition.

While acknowledging that negative results are less likely to be published, Dr. Danielle Ofri, clinical professor of medicine at New York University and editor-in-chief of the Bellevue Literary Review, told Medical News Today, “We’ve certainly seen reports about the side effects of vaccines (recent news about the AstraZeneca vaccine, ongoing issues with J&J).”

She added: The [COVID-19] vaccine studies have been carried out in an environment of unprecedented scrutiny. Every step of these trials is being watched — by the public, by the news media, by the scientific community — [so] it seems impossible to imagine a large-scale hiding of the results.”

Government efforts to mandate vaccination gave opponents more reason to mistrust the vaccine. The first anti-vaccination movements started in the U.K. in the mid-19th century. Others soon followed in the U.S.

And the anti-vaccination propaganda began. Punch, a popular satirical magazine in the U.K. at the time, published a cartoon depicting people being vaccinated then developing cow’s horns, heads, and tails.

Some doctors promoted these views and opposed the vaccine, not on grounds of safety, but because they were making a good living from dubious smallpox cures.

Despite the shaky start, as medical practice improved and vaccinations were developed against other diseases, acceptance of vaccines increased during the 20th century.

By the 1960s, vaccinations became routine against common diseases, such as diphtheria, polio, measles, mumps, and whooping cough. Many were given in infancy. Then, in 1974, a study linked neurological reactions to the whooping cough (pertussis) vaccination.

Parents worried about the safety of the vaccine for their children. Pertussis vaccination rates in England and Wales plummeted from 78.5% of children in 1971 to 37% in 1974, and the winter of 1978-’79 saw the worst whooping cough outbreak in the U.K. since the 1950s.

In the 1980s and 1990s, vaccine confidence recovered. Then, in 1998, Dr. Andrew Wakefield published a paper in The Lancet.

His study alleged that there was a link between the MMR (combined measles, mumps, and rubella) vaccine and autism. Worldwide media coverage followed, sometimes with panic-inducing headlines. Reports implied that the MMR vaccine caused autism, although the study had not actually stated this.

The story rumbled on for more than a decade, resurfacing again in the U.S. in 2006. Although the paper was retracted in 2010, rumors persisted. Dr. Wakefield was struck off the U.K. Medical Register soon after, but he stands by his claims. He is now a leading figure in the U.S. anti-vaccination movement.

The effect on vaccine confidence was profound. Although rates of MMR vaccination in the U.S. and U.K. dropped by only about 10%, questions arose about the safety of all vaccines. As recently as 2018, in a U.K. survey, 55% of respondents believed there might be a link between vaccines and autism.

As soon as SARS-CoV-2 was identified, researchers raced to develop a vaccine. Some depended on tried-and-tested technologies, such as Oxford AstraZeneca, which used an adenovirus. Others were more innovative: Pfizer/BioNTech developed a process to deliver mRNA into cells, which was used for their vaccine.

Governments poured huge amounts of money into the vaccine development program, enabling it to progress rapidly. The first vaccines were approved only a year after SARS-CoV-2 was sequenced.

“Modern science created vaccines that exceeded the expectations of scientists in their effectiveness, and one would have expected that when the vaccines were announced, lines would be stringing on down the street of people waiting to get vaccinated.”

Dr. William Schaffner, professor of infectious diseases at the Vanderbilt University Medical Center, Nashville, TN, speaking to MNT

Some were lining up to get their vaccines, but others were not so keen. The very speed of the vaccine development was a cause of concern for some. Surely, the developers had taken shortcuts? How could they be sure the vaccines were safe?

Rumors abounded about side effects, particularly on social media, with some claiming:

  • The vaccine was developed too fast to be safe.
  • Bill Gates was using the vaccine to insert microchips in everyone.
  • The vaccine made a person infertile.
  • It was dangerous for pregnant people long after being approved for use in them in the U.K.

Scientists countered these rumors with research findings. But research cannot always convince people.

“Information goes to the brain. Attitude is how you feel […] We have not been very good at addressing how people feel about things. Over time, we have made progress.”

– Dr. William Schaffner

Sometimes, vaccine hesitancy comes from unexpected quarters.

Speaking to MNT, Dr. Jon Rogers, a retired physician from the U.K., who has been a vocal opponent of the strict restrictions adopted in England at the start of the pandemic, expressed concerns about the COVID-19 vaccines.

“I think the public are confused. Some doctors are saying this is safe and effective. Others are saying: ‘Hang on, there are side effects,” he claimed.

He continued, expressing sentiments of mistrust: “What are the risks and benefits? That dialogue has not been allowed since April 2020. […] I’m not against vaccines, I’m just questioning the new mRNA vaccine.”

So perhaps more information is not the only key to vaccine acceptance. Many experts believe that trust in those advocating for vaccines is crucial, which has been a concern during the COVID-19 pandemic.

“It’s all about trust. Most people (including most health professionals!) can’t dig into the nitty-gritty of a scientific study to render a judgment on how valid the data are. We all have to rely on others to make a recommendation. That reliance is entirely dependent on trust.”

– Dr. Danielle Ofri

Dr. Ofri continued: “We in healthcare trust Dr. Fauci because we’ve known him for years. He led us through the AIDS crisis and was always a straight-arrow scientist and human being. At the same time, if the rumor-mill sows distrust about him, then average citizens will be less likely to believe what he says.”

People who question the benefits of vaccination often state that they are happy to take the risk of not being vaccinated.

Dr. Schaffner expressed his frustration with this view: “This [virus] is very contagious. Not being vaccinated […] is akin to coming to a red light and driving. You have exerted your own independence, you accept some risk, but you put people around you at risk.”

The WHO has called vaccine hesitancy one of the top 10 threats to global health. So how can this be countered?

Some countries are mandating the vaccine for people in some occupations, such as health and care workers. Others, such as Austria, are planning a national mandate. But mandates seldom persuade the hesitant.

As Prof. Heidi Larson notes in her book Stuck, mandates strike “libertarian nerves.” This is evidenced by Dr. Rogers: “I chose not to be vaccinated because of the coercion that’s been put on lots of other people to be vaccinated. It’s bloody mindedness, really.”

Dr. Schaffner believes that trust must be regained: “There seems to be an active mistrust of science and, over the past 20 or 30 years, just an erosion of trust in government generally. And, of course, much of this information comes via the government, as it should.”

While some will always oppose vaccination, for those who are hesitant, contact with trusted health professionals is likely to be the most effective route to acceptance.

“It seems to be most effective when patients are counseled by their own doctor rather than by national health authorities. While I have a few patients who are dead-set against the vaccine, for the in-between group who is just very unsure, our one-on-one conversations have been very helpful and many have gotten the vaccine.”

– Dr. Danielle Ofri.

So, perhaps we should focus on the messenger — not just the message — when communicating with those still hesitant about COVID-19 vaccines.

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