Key Terms You Must Know

📖 Key Terms You Must Know

Edward Jenner (1749-1823)

English country doctor who developed the world's first scientifically-tested vaccine in 1796. Noticed that milkmaids who caught cowpox did not contract smallpox. Tested his hypothesis by vaccinating 8-year-old James Phipps with cowpox material from milkmaid Sarah Nelmes, then attempting to infect him with smallpox — Phipps remained healthy. Published his findings in 1798 and named the procedure "vaccination" (from Latin vacca, meaning cow). Could not explain WHY vaccination worked — germ theory was not developed until 1861. Government gave him £30,000 to promote his discovery.

Vaccination

The deliberate introduction of a weakened or related pathogen into a person to stimulate immunity without causing the disease itself. Jenner's original vaccination used cowpox material to protect against smallpox. The word comes from the Latin vacca (cow). Jenner's vaccination was effective but limited: it only worked for smallpox, and he could not explain why. Pasteur extended the principle in the 1880s, developing vaccines for chicken cholera, anthrax, and rabies after germ theory provided the scientific explanation for how vaccination worked.

Variolation

The practice of deliberately infecting a person with material from a mild smallpox case to create immunity. Introduced to England from Turkey by Lady Mary Wortley Montagu in 1721. It worked — it did create immunity — but carried a death risk of approximately 1-2%. Jenner's vaccination replaced variolation by using the safer cowpox material. Inoculators (doctors who performed variolation) opposed Jenner because his safer method threatened their livelihood. Variolation is the important predecessor to vaccination — it established the principle of deliberate infection for immunity.

1853 Vaccination Act

An Act of Parliament making vaccination against smallpox compulsory for all infants in England and Wales. The first time any medical procedure had been made legally compulsory by the British government — a significant departure from the laissez-faire principle that individuals should make their own health decisions. It led directly to a dramatic fall in smallpox deaths. It also provoked fierce resistance: the National Anti-Vaccination League was formed, and many parents refused to comply. The Act represents a crucial moment in the history of government responsibility for public health.

Smallpox

A highly contagious viral disease causing a distinctive rash of fluid-filled blisters across the body. Before vaccination, it killed approximately 400,000 Europeans per year and blinded or scarred many survivors. It was one of the most feared diseases in the world. Jenner's vaccination progressively reduced its impact: it was eliminated from England by the late 19th century and declared globally eradicated by the World Health Organisation in 1980 — the first (and so far only) infectious disease to be completely eliminated from the world through human effort.