From Ancient Precursors to Jenner’s Breakthrough
The earliest known evidence of smallpox dates back thousands of years, found in Egyptian mummies. Over centuries, the disease swept through populations in repeated outbreaks. In the New World, it arrived with European contact and devastated Native American communities. In Europe during the 1700s, smallpox was a leading cause of death and blindness, striking rich and poor alike. Several European monarchs died from the disease. Prevention measures emerged long before modern medicine. Inoculation — deliberately exposing a person to mild smallpox material to trigger immunity — appeared in China around the 1500s. That practice spread to Europe in the early 1700s. In 1796, English physician Edward Jenner took the next step. Using material from cowpox lesions, he inoculated an 8-year-old boy against smallpox, creating the first vaccine. That method was safer and more reliable than older inoculation techniques. Jenner’s work built upon earlier folk practices of variolation, documented across Asia and Africa. The global fight against smallpox culminated in the intensive eradication campaign of the 1960s. The last naturally occurring case was diagnosed in 1977, and the disease was declared eradicated in 1980.
A Century of Breakthroughs
Nearly a century after Jenner, in 1885, Louis Pasteur developed the first rabies vaccine, marking another turning point in the biological fight against infectious disease. The 20th century brought a cascade of breakthroughs. According to the medical literature, the diphtheria vaccine arrived in 1913, followed by the BCG vaccine for tuberculosis in 1921. Jonas Salk’s polio vaccine was introduced in 1955, with Albert Sabin’s oral version following in 1961. The measles vaccine came in 1963, the mumps vaccine in 1967, and the rubella vaccine in 1969. The World Health Organization launched its Expanded Programme on Immunization in 1974. By 2020, according to public health data, vaccines were preventing an estimated 2 to 3 million deaths annually from diphtheria, tetanus, pertussis, and measles alone. UNICEF figures indicate that vaccines have reduced child mortality by over 50 percent since 1990.
The COVID-19 Watershed
The COVID-19 pandemic fundamentally altered the timeline of vaccine development. The first authorized vaccine — the Pfizer-BioNTech product — received emergency use authorization in December 2020, just 11 months after the SARS-CoV-2 virus was sequenced. That pace was unprecedented in the history of medicine. As of 2023, the record shows that over 13 billion COVID-19 vaccine doses had been administered globally. The scale of that deployment represented the largest and fastest vaccination campaign ever conducted. The biological mechanism remains consistent across these efforts. Vaccines are biological preparations that provide active acquired immunity to particular infectious diseases. The science, refined over more than two centuries, continues to evolve. Consult your doctor for medical advice. For readers today, the story of smallpox shows how a single disease, once a constant threat, can be consigned to history through science and collective action — a lesson that has laid the foundation for all subsequent immunization efforts.
