History of Vaccination in Timeline

Vaccination involves administering a vaccine to stimulate the immune system and develop immunity against a disease. Vaccines contain weakened, live, or killed microorganisms (or their components) that trigger the body's adaptive immunity, thus preventing illness. A high vaccination rate within a population leads to herd immunity, protecting vulnerable individuals who cannot receive vaccines themselves. This collective immunity helps curtail the spread of infectious diseases and safeguards public health by minimizing the risk of outbreaks.

1905: U.S. Supreme Court upheld compulsory vaccination laws

In 1905, the U.S. Supreme Court upheld compulsory vaccination laws in the landmark case Jacobson v. Massachusetts, ruling that laws could require vaccination to protect the public from dangerous communicable diseases.

1959: WHO called for the eradication of smallpox worldwide

In 1959, the WHO called for the eradication of smallpox worldwide, as smallpox was still endemic in 33 countries.

1963: Introduction of the measles vaccine

In wealthy nations the number of measles cases had dropped dramatically after the introduction of the measles vaccine in 1963.

1966: Smallpox cases worldwide

According to the WHO, in 1966 there were about 100 million cases of smallpox worldwide, causing an estimated two million deaths.

1974: WHO smallpox vaccination program confines smallpox

By 1974, the WHO smallpox vaccination program had confined smallpox to parts of Pakistan, India, Bangladesh, Ethiopia, and Somalia.

1974: WHO adopted the goal of universal vaccination by 1990

In 1974 the WHO adopted the goal of universal vaccination by 1990 to protect children against six preventable infectious diseases: measles, poliomyelitis, diphtheria, whooping cough, tetanus, and tuberculosis.

1974: Vaccination prevents millions of deaths

In 1974, a WHO-funded study by The Lancet estimated that vaccination prevented 154 million deaths during the 50-year period starting in 1974, including 146 million among children under age 5.

1977: Last case of smallpox infection acquired outside a laboratory

In 1977, the WHO recorded the last case of smallpox infection acquired outside a laboratory in Somalia.

1979: Smallpox eradicated

In 1979, smallpox was finally eradicated, after killing an estimated 300–500 million people in the 20th century.

1980: WHO declared the world free of smallpox

In 1980, the WHO officially declared the world free of smallpox.

1990: Vaccination rates in developing countries

In the 1980s, up to 1990, only 20 to 40% of children in developing countries were vaccinated against six diseases.

1998: Publication of Andrew Wakefield's paper

In 1998, the physician Andrew Wakefield published a paper that concluded that eight of the twelve patients, aged three years of age to 10 years of age, developed behavioral symptoms consistent with autism following the administration of the MMR vaccine. The article was widely criticized for lack of scientific rigor and it was proven that Wakefield falsified data in the article.

2000: Vaccinations prevented 50 million deaths from 2000 to 2019

According to a 2021 paper, vaccinations against haemophilus influenzae type b, hepatitis B, human papillomavirus, Japanese encephalitis, measles, neisseria meningitidis serogroup A, rotavirus, rubella, streptococcus pneumoniae, and yellow fever have prevented an estimated 50 million deaths from 2000 to 2019.

2000: Establishment of the Global Alliance for Vaccines and Immunization

In 2000, the Global Alliance for Vaccines and Immunization was established to strengthen routine vaccinations and introduce new and underused vaccines in countries with a per capita GDP of under US$1,000.

2001: Thimerosal removed from childhood vaccines in the United States

In 2001, thimerosal was removed from childhood vaccines in the United States as a precaution, even though evidence supported its safety and efficacy. Thimerosal had been used as a preservative to prevent the growth of bacteria and fungi in multi-dose vaccine vials.

2003: SARS outbreak cost $54 billion

In 2003, the SARS outbreak in East Asia cost $54 billion.

2004: Retraction by Wakefield's co-authors

In 2004, 10 of the original 12 co-authors (not including Wakefield) published a retraction of the article and stated the following: "We wish to make it clear that in this paper no causal link was established between MMR vaccine and autism as the data were insufficient."

2006: Eradication of polio requires improved sanitation

By 2006 global health experts concluded that the eradication of polio was only possible if the supply of drinking water and sanitation facilities were improved in slums.

2007: Studies on the effectiveness of vaccines

In 2007, studies regarding the effectiveness of vaccines on mortality or morbidity rates of those exposed to various diseases found almost 100% decreases in death rates, and about a 90% decrease in exposure rates.

2009: Pandemrix adverse events and CDC study

In 2009, Pandemrix, a vaccine for the H1N1 pandemic given to around 31 million people, was found to have a higher level of adverse events than alternative vaccines, resulting in legal action. In response to the narcolepsy reports following immunization with Pandemrix, the CDC carried out a population-based study and found the FDA-approved 2009 H1N1 flu shots were not associated with an increased risk for the neurological disorder.

2009: Public Health Law Research report on vaccination requirements

In 2009, Public Health Law Research reported that there is insufficient evidence to assess the effectiveness of requiring vaccinations as a condition for specified jobs, sufficient evidence supporting the effectiveness of requiring vaccinations for child care and schools, and strong evidence supporting the effectiveness of standing orders for vaccine administration.

2010: Retraction of Wakefield's paper by The Lancet

In 2010, The Lancet officially retracted Andrew Wakefield's article, stating that several elements of the article were incorrect, including falsified data and protocols. The article has sparked a much greater anti-vaccination movement, particularly in the United States, and even though the article was shown to be fraudulent and was heavily retracted, one in four parents still believe that vaccines can cause autism.

2011: Andrew Wakefield's medical license was revoked

In 2011, Andrew Wakefield, a leading proponent of the theory that MMR vaccine causes autism, was found to have been financially motivated to falsify research data and was subsequently stripped of his medical license.

2013: WHO estimates on vaccine-preventable deaths

In 2013, the World Health Organization (WHO) estimated that 29% of deaths of children under five-years-old were vaccine preventable.

2015: Study confirms no link between autism and the MMR vaccine

In 2015, a study was published confirming that there is no link between autism and the MMR vaccine. Infants were given a health plan, that included an MMR vaccine, and were continuously studied until they reached five years old. There was no link between the vaccine and children who had a normally developed sibling or a sibling that had autism making them a higher risk for developing autism themselves.

2017: Suspension of Dengvaxia program in the Philippines

In 2017, a mass vaccination program in the Philippines was suspended after Dengvaxia, the only approved vaccine for Dengue fever, was found to increase the risk of hospitalization for Dengue fever by 1.58 times in children of 9 years or younger.

2019: Vaccinations prevented 50 million deaths from 2000 to 2019

December 2020: COVID‑19 vaccinations prevented 14.4 to 19.8 million deaths

According to a June 2022 study, COVID‑19 vaccinations prevented an additional 14.4 to 19.8 million deaths in 185 countries and territories from 8 December 2020 to 8 December 2021.

2020: UNICEF reports children missed vaccinations due to the COVID-19 pandemic

UNICEF has reported on the extent to which children missed out on vaccinations from 2020 onwards due to the COVID-19 pandemic.

December 2021: COVID‑19 vaccinations prevented 14.4 to 19.8 million deaths

According to a June 2022 study, COVID‑19 vaccinations prevented an additional 14.4 to 19.8 million deaths in 185 countries and territories from 8 December 2020 to 8 December 2021.

2021: Vaccinations prevented 50 million deaths from 2000 to 2019

June 2022: COVID‑19 vaccinations prevented 14.4 to 19.8 million deaths

According to a June 2022 study, COVID‑19 vaccinations prevented an additional 14.4 to 19.8 million deaths in 185 countries and territories from 8 December 2020 to 8 December 2021.

2022: Increase in unvaccinated children

In 2022, the number of children who did not receive a single dose of the vaccine increased from 13.9 million in 2022 to 14.5 million in 2023.

2023: UNICEF reports vaccination programs are getting 'back on track'

By summer 2023, UNICEF described vaccination programs as getting "back on track" after the COVID-19 pandemic.

2023: DTP Vaccination coverage stalled at 84%

In 2023, a WHO/UNICEF report found that the number of children who received three doses of the vaccine against diphtheria, tetanus and pertussis (DTP) in 2023 stalled at 84% (108 million), a key marker for global immunization coverage. The number of children who did not receive a single dose of the vaccine increased from 13.9 million in 2022 to 14.5 million in 2023.

2024: WHO/UNICEF Report on Immunization Coverage

In 2024, a WHO/UNICEF report indicated that global immunization coverage with three doses of the DTP vaccine (diphtheria, tetanus, and pertussis) stalled at 84% (108 million) in 2023. The number of children who did not receive a single dose of the vaccine increased from 13.9 million in 2022 to 14.5 million in 2023.