Since the beginning of human existence, diseases, varying in severity from mild to deadly, have been a threat to life. Humans, from time immemorial, have developed ways to prevent and treat diseases – a field we call medicine. While medicine offers different solutions, the most efficient, unarguably, is vaccination. This is because vaccines prevent diseases from occurring in the first place. According to the World Health Organization (WHO), vaccines prevent about 3.5 to 5 million deaths annually from diseases, such as diphtheria, tetanus, pertussis, measles, influenza, polio, among others. Yet, despite this revolution, vaccines continue to be misunderstood and resisted. Forces on the opposite sides of the debate have come to be known as pro-vaxxers and anti-vaxxers. But since we cannot reduce the argument to whether vaccines are good or bad, we must scrutinize the misconceptions and unravel the truth.
Origin
The 1300s to 1700s
As early as the 14th century, the Chinese attempted to prevent smallpox by blowing powdered smallpox particles into the noses of healthy people – a practice they called variolation (after the French word for smallpox, ‘la variole’). Upon observing variolation in the Ottoman Empire, Mary Wortley took the practice to Europe and inoculated her two daughters against smallpox. In 1774, Benjamin Jesty informally tested his hypothesis that infection with cowpox could prevent smallpox. In May 1796, Edward Jenner – known as the Father of Vaccines – scientifically tested Jesty’s hypothesis by inoculating 8-year-old James Phipps with fluid from a cowpox sore. Phipps fell sick for several days before he fully recovered. Two months later, Jenner infected Phipps with fluid from a smallpox sore to test his resistance. Phipps remained healthy, becoming the first person to be vaccinated against smallpox. After that, Jener vaccinated his own children. In 1798, he published his findings in An Inquiry into the Causes and Effects of the Variolae Vaccinae. The smallpox vaccine was adopted for public use, and the term ‘vaccine’ was later coined from the Latin word for cow, ‘vacca’.
The 1800s to 1900s
In 1872, Louis Pasteur developed the fowl cholera vaccine. In 1881, he discovered the anthrax vaccine, and then the rabies vaccine in 1885. Pasteur’s discoveries triggered intensive research for more vaccines. In 1894, Anna Wessels isolated a bacterial strain that led to the development of the diphtheria vaccine. In 1921, the tuberculosis vaccine, known as Bacillus Calmette-Guérin (BCG), was developed by Albert Calmette and Camille Guérin. Later, in 1924, Pierre Descombey developed the tetanus vaccine. From 1918 to 1919, the Spanish Flu epidemic killed an estimated 20-50 million people, spurring the development of the influenza vaccine in 1938, with approval by the FDA in 1945. Around the same time, in 1937, the yellow fever vaccine was developed, with approval in 1938. Later milestones include the pertussis vaccine by Pearl Kendrick and Grace Eldering in 1939; the polio vaccine by Jonas Salk in 1955, with Albert Sabin creating the oral version in 1960; the hepatitis B vaccine by Baruch Blumberg and Irving Millman in 1969; the combined measle-mumps-rubella (MMR) vaccine by Maurice Hilleman in 1971; and the Haemophilus influenza type b vaccine by David Hamilton in 1985. By 1980, smallpox had been eradicated and polio cases had declined by 99% since 1988.
The 21st Century
Following the discovery in 1995 that the human papillomavirus (HPV) is responsible for cervical cancer, the HPV vaccine was developed and later approved in 2006. In response to the 2024 Ebola virus outbreak in West Africa, the FDA approved the first Ebola vaccine in 2019. In July 2022, the first malaria vaccine, RTS,S/AS01, was prequalified by the WHO, while the second vaccine, R21/Matrix-M, was prequalified in December 2023. In a swift response to the COVID-19 pandemic, two COVID-19 vaccines – Moderna and Pfizer – were developed in record-breaking time of approximately 11 months. The FDA granted both vaccines Emergency Use Authorization (EUA) in December 2020 before fully approving Pfizer in August 2021 and Moderna in January 2022. In 2022, the FDA also approved a third-generation smallpox vaccine for the prevention of monkeypox. Research and clinical trials for more vaccines are ongoing, with HIV being the most studied.
Misconceptions And The Truth about Vaccines
Misconceptions often arise from incomplete or inaccurate information, myths, rumours, religious and traditional beliefs, misinterpretation of scientific data, or outright ignorance. Misconceptions create fear and mistrust, leading to vaccine hesitancy – the delay or complete refusal to take vaccines despite their availability. The line chart below reveals the alarming increase in vaccine hesitancy in selected countries. Nigeria’s seemingly low 11% rate means a staggering 25.3 million people are hesitant to vaccines despite the unavailability of data in some regions.
Vaccine hesitancy has existed for as long as vaccines have existed; it has only worsened over time, with the recorded highest rates during the COVID-19 pandemic, majorly against the COVID-19 vaccine. As far back as the late 18th century, Edward Jenner’s smallpox vaccine faced resistance because people believed that being injecting animal‑derived material could harm them. Through the 19th and 20th centuries, many people resisted pertussis vaccine, their claims driven by assumptions rather than evidence. By the late 20th century, the resistance shifted to the combined measles, mumps, and rubella (MMR) vaccine, culminating in the controversial but now-discredited claims linking vaccines to autism
The false belief that MMR vaccine causes autism originated from a 1998 Lancet study by Andrew Wakefield, a British surgeon. The study suggested that MMR vaccine increases the risk of autism among children. However, upon review by the General Medical Council (GMC) of the United Kingdom, Wakefield’s findings were discredited for procedural breach and ethical misconduct. Several studies that followed found no link between the MMR vaccine and autism. The publication was retracted in February 2010 and Wakefield lost his medical license. Despite this evidence, many continue to uphold the false claim that MMR vaccine caused autism, with Donald Trump recklessly saying it at a press conference on September 22, 2025.
Similarly, in 1974, pertussis vaccine was wrongly linked to neurological complications by two retrospective case reports published in Great Britain by Kulenkampff and Stewart. Their claims triggered a surge in vaccine hesitancy, with many parents refusing to vaccinate their children against pertussis. As a result, vaccination coverage fell drastically from over 80% in 1974 to 31% in 1978. This led to pertussis outbreak from 1977 to 1979, resulting in 102,500 cases and 36 deaths. In England and Wales alone, an estimated 5,000 children were hospitalized. In response, a Joint Committee on Vaccination and Immunization designed a prospective study to evaluate the risk of brain damage from pertussis vaccine. Comparing vaccinated cases and controls, the risk was found to be one in 110,000, thus disproving the claim that pertussis vaccine causes brain damage.
A lot of misconceptions about vaccines are propagated by religious and traditional beliefs. These misconceptions are often spearheaded by the religious and traditional leaders. One notable incidence occurred in July 2003 when religious leaders in five northern Nigerian states boycotted polio vaccination because they suspected that the vaccines were contaminated with infertility and HIV causing agents. They claimed it was a Western plot to sterilize Muslims and infect them with AIDS. Datti Ahmed, a physician and leader of the Sharia Court at the time was quoted saying, “We believe that modern-day Hitlers have deliberately adulterated the oral polio vaccines with anti-fertility drugs and certain viruses which are known to cause HIV and AIDS”. Sule Ya’u Sule, speaking for the Kano governor, also said, “Since September 11, the Muslim world is beginning to be suspicious of any move from the Western world.” Consequently, an outbreak of measles erupted, spreading to other parts of Nigeria and resulting in over 20,000 cases and 600 deaths from January to March 2005.
In today’s Nigeria, religious and traditional leaders continue to propagate false claims about vaccines. This is particularly disturbing as these leaders have followers in the millions who believe whatever they say. In fact, a study by Afrobarometer shows that 60% of Nigerians trust their religious leaders more than any public institution. Yet, these same religious leaders encourage their followers to refuse vaccination and feed them with false information about vaccines and diseases. For example, Pastor Chris Oyakhilome, a televangelist with a global influence, made one of the most outrageous claims when he said COVID-19 resulted from 5G technology. He went further to assert that the COVID-19 vaccine is dangerous and alters the DNA, claiming that the Pope died from taking the vaccine. Discouraging his church members from taking the vaccine, Bishop David Oyedepo, said during a sermon in May 2021, “…They wanted Africa dead. I heard them say it. When we are not dying, they now said how can we kill them faster…be careful of that deadly thing called vaccine…” In recent times, one of the most prevalent misconceptions is that vaccines are a plot to depopulate the world. Obviously, these false claims propel vaccine hesitancy.
The COVID-19 vaccine faced huge resistance because its development process was fast-tracked. Many believed this made the vaccine unsafe because it skipped rigorous safety and efficacy checks. Contrary to these claims, the mRNA technology, which was used to develop the COVID-19 vaccine, has been in existence since the 1990s. The technology was adopted by the scientific community when it was found to be the most effective technique. As such, the method used was not entirely new. Moreover, not all stages of clinical trials were fast-tracked. As Dr Andrew Badley, a member of the COVID-19 Research Task Force, clarified, “the fast-tracked parts were regulatory approvals, funding, data analysis, and submission to the FDA. What was not fast-tracked was enrollment of patients, clinical follow-up of these patients, capturing the events which occurred...” These stages that were not fast-tracked involve safety and efficacy evaluation, and having successfully passed them, the vaccine is considered safe and effective.
Fear of side effects is another reason for hesitancy. Some even think they are being infected with the virus. Contrary to these claims, side effects were anticipated because they occur due to the body’s response to the spike protein produced by the vaccine. Now, it is important to understand that mRNA is the blueprint for making proteins. When the vaccine is administered, it passes through the cell membrane into the cytoplasm and then instructs the cell to produce a spike protein, which is very similar to that of the corona virus. The mRNA cannot enter the nucleus, so there is no way it can alter the DNA. Once the body’s immune system identifies this foreign protein, it launches an attack against it by creating antibodies. This results in the symptoms we call side effects. The vast majority of side effects are mild and temporary, and more serious or long-lasting effects are extremely rare.
Another misconception about vaccines is the belief that natural immunity is better than vaccine-derived immunity, a belief widely propagated among those who think they have a naturally strong immunity. Contrary to these beliefs, whether a person has strong immunity against a disease can only be ascertained if the person is not eventually infected. This means the person would be infected if otherwise, which is a dangerous gamble. It is safer to take a vaccine that is not needed than to become infected with a disease that the vaccine can no longer help prevent. Natural immunity is no different from vaccine-derived immunity because the body produces antibodies using the same mechanism. For immunity to be natural, the body must be exposed to the disease; if lucky, antibodies are formed without the person becoming sick. Otherwise, the person falls ill and recovers, during which antibodies would have formed to protect against future infections. Unfortunately, some diseases – such as pertussis, influenza, and COVID-19 – do not produce reliable natural immunity, while some are so severe that they could lead to death, dashing all hopes of natural immunity. Vaccines prevent both the disease and the harmful consequences of this false belief.
People also believe that there is no need for the vaccines if the disease prevalence is low. It is important to understand that vaccination is what made the disease prevalence low in the first place and refusing vaccines for this reason only poses the risk of a resurgence. Similar to this claim is the belief that vaccines are unnecessary if many people around have been vaccinated. This claim hinges on herd immunity. Herd immunity occurs when a large proportion of a population gets vaccinated, making disease transmission unlikely. People who benefit from herd immunity include children too young to be vaccinated, pregnant women, the elderly with weaker immune systems, those who cannot develop immunity with the vaccine, and surgery or organ transplant patients. Contrary to this claim, it is still necessary to get vaccinated, at least to protect those who cannot.
Another widespread misconception about vaccines is that vaccines end up infecting people with the disease they are trying to prevent. As loud as this claim seems, vaccines do not infect people with the disease they are trying to prevent. The only documented case of an infection caused by vaccines is oral polio vaccine which has a very low incidence of 0.42 times per million doses of the oral polio vaccine (a live attenuated vaccine). Of course, this risk is far smaller than the enormous benefit we have had from polio vaccines. Vaccines are highly unlikely to infect people with the disease they are preventing because they contain a weaker form of the disease-causing agent (e.g., virus or bacteria) that cannot harm the body aside from side effects which may occur due to the body’s immune response. Most vaccines are inactivated (where the virus or bacteria is killed), and there are relatively few live attenuated vaccines. Inactivated vaccines cannot cause the disease they are trying to prevent.
In 2019, the WHO declared vaccine hesitancy as one of the top ten global health threats. Vaccine hesitancy has lowered vaccination coverage globally, resulting in outbreaks and reemergence of vaccine-preventable disease such as measles, meningitis, yellow fever, and diphtheria. According to the WHO, an estimated 14.5 million children missed all of their routine vaccine doses in 2023, an increase from 13.9 million in 2022 and 12.9 million in 2019. That same year, measles cases reached an estimated 10.3 million, a 20% increase from 2022. Since December 2022, Nigeria has been facing an outbreak of diphtheria, with a total of 40,060 confirmed cases, of which only 5974 (14.3%) were fully vaccinated against diphtheria. These outbreaks result from low vaccine coverage, which, among other systemic issues, is caused by vaccine hesitancy, which stems from misconceptions about vaccines.
Unarguably, vaccines have tremendously benefited humanity, from the eradication of smallpox to the decline in polio cases by 99%, the reduction in tetanus cases by over 97%, and the prevention of nearly 59 million measles-related deaths. In the words of the WHO Director-General, Dr Tedros Adhanom Ghebreyesus, “Vaccines have saved more than 150 million lives over the past five decades.” Be it as it may, misconceptions about vaccines never cease to circulate, but we must continue to scrutinize them while unravelling the truth.
