History of Vaccination in Timeline

By Popular Timelines Editorial Team · Updated: July 13, 2026

Vaccination is a critical public health intervention designed to provide immunity against infectious diseases. By introducing a harmless component of a pathogen—such as an inactivated virus, protein, or mRNA—into the body, vaccines stimulate the immune system to recognize and remember specific threats without causing the disease itself. This process triggers the production of antibodies and the activation of memory cells, ensuring a rapid and effective response if the individual is exposed to the actual pathogen in the future. Beyond individual protection, high vaccination coverage achieves 'herd immunity,' which reduces the transmission of diseases within a population, protecting vulnerable individuals who cannot be vaccinated. Vaccines have been instrumental in the global eradication of smallpox, the near-elimination of polio, and the drastic reduction of mortality rates associated with illnesses like measles and influenza. By preventing outbreaks and long-term health complications, vaccination remains one of the most effective and cost-efficient medical tools for enhancing life expectancy and global health security.

1905: Jacobson v. Massachusetts

In 1905, the U.S. Supreme Court ruled in the case of Jacobson v. Massachusetts that states have the authority to enforce compulsory vaccination laws to safeguard the public against communicable diseases.

1959: WHO Call for Smallpox Eradication

In 1959, the World Health Organization (WHO) launched a global initiative to eradicate smallpox, noting that the disease remained endemic in 33 countries at that time.

1963: Introduction of the Measles Vaccine

The measles vaccine was introduced in 1963, leading to a significant and dramatic decline in the number of measles cases across wealthy nations following its implementation.

1966: Smallpox Global Statistics

According to World Health Organization records from 1966, there were approximately 100 million cases of smallpox reported globally, resulting in an estimated two million fatalities.

1974: Containment of Smallpox

By 1974, the World Health Organization's vaccination efforts had successfully confined the smallpox virus to limited regions within Pakistan, India, Bangladesh, Ethiopia, and Somalia.

1974: WHO Goal for Universal Vaccination

In 1974, the World Health Organization established a global objective to achieve universal vaccination by 1990, aiming to protect children from six specific infectious diseases: measles, poliomyelitis, diphtheria, whooping cough, tetanus, and tuberculosis.

1974: Start of a 50-year Period for Vaccination Impact Study

Starting in 1974, a 50-year period was analyzed in a World Health Organization-funded study published in The Lancet, which estimated that vaccination efforts saved 154 million lives, with 146 million of those being children under the age of 5.

1977: Last Natural Smallpox Case

In 1977, the World Health Organization documented the final naturally acquired smallpox infection, which occurred in Somalia.

1979: Global Eradication of Smallpox

In 1979, smallpox was officially declared eradicated, marking the end of a disease that had claimed the lives of an estimated 300 to 500 million people during the 20th century alone.

1980: Official Eradication of Smallpox

The World Health Organization officially declared the world free of smallpox in 1980, marking a major milestone in medical history.

1990: Deadline for Universal Vaccination Goal

By 1990, the target year set in 1974, the WHO evaluated progress toward its goal of universal childhood vaccination against six major preventable infectious diseases.

1998: Publication of Wakefield MMR Study

In 1998, physician Andrew Wakefield published a paper suggesting a potential link between the MMR vaccine and the development of autism in children, a study that was later proven to be based on falsified data.

2000: Establishment of the Global Alliance for Vaccines and Immunization

In 2000, the Global Alliance for Vaccines and Immunization was formed with the primary objective of improving routine vaccination efforts and facilitating the introduction of underutilized vaccines specifically within nations that maintained a per capita GDP of less than US$1,000.

2001: Removal of Thimerosal from U.S. Childhood Vaccines

In 2001, thimerosal was officially removed from childhood vaccines in the United States as a precautionary measure, despite scientific evidence confirming that the preservative was safe and effective for preventing bacterial and fungal contamination in multi-dose vaccine vials.

2004: Partial Retraction of Wakefield Study

During 2004, ten of the twelve original co-authors of the 1998 study published a retraction, clarifying that no causal link between the MMR vaccine and autism had been established due to insufficient data.

2006: Polio Eradication Strategy Update

In 2006, global health experts concluded that the eradication of polio could not rely on vaccination alone and required essential improvements to drinking water and sanitation infrastructure in high-risk slum areas.

2007: Vaccine Effectiveness Research Study

In 2007, research investigating the impact of vaccines on disease outcomes revealed that vaccination contributed to nearly a 100% reduction in mortality rates and approximately a 90% decrease in exposure rates for various infectious diseases.

2009: H1N1 Pandemic Vaccination and Safety Investigation

During the 2009 H1N1 pandemic, the vaccine Pandemrix was administered to approximately 31 million people, but it was later linked to higher rates of adverse events and subsequent legal action. In response to concerns regarding narcolepsy, the CDC conducted a study in 2009 and concluded that FDA-approved 2009 H1N1 flu shots did not increase the risk of the neurological disorder.

2009: Public Health Law Research Assessment of Vaccine Mandates

In 2009, Public Health Law Research published findings regarding vaccine mandates, noting that while there was sufficient evidence to support mandatory vaccinations for childcare and school attendance and strong evidence for the use of standing orders by healthcare workers, there remained insufficient evidence in 2009 to conclude that requiring vaccinations for specific jobs effectively reduces disease incidence among vulnerable groups.

2010: Official Retraction by The Lancet

In 2010, the medical journal The Lancet officially retracted the 1998 study in its entirety, citing falsified data and incorrect protocols as the primary reasons for the decision.

2011: Andrew Wakefield Discredited and Stripped of License

In 2011, Andrew Wakefield, a prominent advocate for the theory linking the MMR vaccine to autism, was investigated and found to have falsified research data for financial gain. As a result of this misconduct, his medical license was revoked in 2011.

2013: WHO assessment of vaccine-preventable child mortality

In 2013, the World Health Organization estimated that approximately 29% of deaths among children under the age of five were caused by diseases that could have been prevented through vaccination.

2015: MMR Vaccine and Autism Correlation Study

In 2015, a definitive study was published that examined the health outcomes of infants receiving the MMR vaccine. By tracking children until they reached the age of five, researchers confirmed there is no link between the MMR vaccine and the development of autism, even among children with siblings who were already diagnosed with the condition.

2017: Suspension of Philippines Dengue Vaccination Program

In 2017, the mass vaccination program for Dengue fever in the Philippines was suspended after findings revealed that the vaccine Dengvaxia significantly increased the risk of severe hospitalization by 1.58 times in children aged 9 and younger.

2020: Disruption of vaccination due to COVID-19

Beginning in 2020, the COVID-19 pandemic caused significant global disruptions to childhood immunization programs, leading to a period where many children missed their scheduled vaccinations.

2022: Baseline for Unvaccinated Children

In 2022, the count of children who did not receive a single dose of the DTP vaccine was recorded at 13.9 million, serving as a comparative figure for rising trends in 2023.

2023: Vaccination program recovery

By the summer of 2023, UNICEF reported that global vaccination programs were successfully returning to their regular schedules and getting back on track following the setbacks caused by the pandemic.

2023: Stagnation of DTP Vaccine Coverage

During 2023, global vaccination coverage for the DTP vaccine stalled at 84%, affecting 108 million children, while the number of children missing all vaccine doses rose to 14.5 million.

2024: WHO/UNICEF Immunization Coverage Report

In 2024, a report released by the WHO and UNICEF highlighted the current state of global immunization coverage, noting the trends in vaccine accessibility for children.