Overview
This lecture traces the history of vaccines from ancient practices through major scientific breakthroughs to the rollout of modern vaccines, highlighting key events, figures, and innovations.
Early Inoculation and Smallpox Control
- Variolation, an early form of inoculation, was practiced before Edward Jenner's vaccine.
- In 1721, Boston's smallpox epidemic led to the first variolation in the Americas by Zabdiel Boylston.
- George Washington ordered mandatory inoculation of the Continental Army against smallpox in 1777.
Jenner and the Birth of Vaccination
- In 1796, Edward Jenner used cowpox to protect against smallpox, founding modern vaccination.
- Jenner's method involved inoculating an eight-year-old with cowpox, who then resisted smallpox infection.
Pasteur and Germ Theory
- Louis Pasteur pioneered germ theory, leading to the first laboratory vaccine (rabies) in 1885.
- Pasteur successfully treated Joseph Meister for rabies post-exposure.
Antitoxins and Vaccine Quality Control
- Diphtheria and tetanus antitoxins were developed in the late 1800s.
- The 1902 Biologics Control Act established federal regulation over vaccine quality in the US.
- Early vaccine trials, like Haffkine's cholera vaccine, introduced the use of control groups.
Major 20th Century Vaccine Developments
- March of Dimes (1938) funded polio research, leading to Salk’s and Sabin’s vaccines.
- Combination MMR vaccine (measles, mumps, rubella) licensed in 1971, simplifying immunization.
- Massive vaccination campaigns, like New York’s 1947 smallpox drive, controlled outbreaks.
Eradication and New Vaccines (Post-1975)
- The last wild cases of smallpox occurred in the 1970s; smallpox was declared eradicated in 1980.
- Polio was eliminated from the Americas in 1994; measles eliminated in the US by 2000.
- New vaccines for Hib, rotavirus, and acellular whooping cough were introduced.
The Modern Era and mRNA Revolution
- HPV vaccine was licensed in 2006, offering protection against cancer-causing viruses.
- First COVID-19 mRNA vaccines administered in the US in December 2020.
- Malaria vaccine recommended by the WHO in 2021.
- 2023 Nobel Prize awarded for mRNA vaccine technology.
Key Terms & Definitions
- Variolation — Early method of inducing smallpox immunity by exposing people to live virus material.
- Vaccination — Administration of weakened or inactive pathogens to stimulate immune protection.
- Antitoxin — Antibody-containing serum used to neutralize bacterial toxins.
- mRNA Vaccine — Vaccine using messenger RNA to instruct cells to make a viral protein, triggering immunity.
Action Items / Next Steps
- Review the key events and figures in the vaccine timeline for exam preparation.
- Study the differences between variolation, vaccination, and antitoxin therapies.
- Familiarize yourself with the modern vaccine schedule and recent vaccine breakthroughs.