History of Vaccines: From Jenner's Smallpox Vaccine to mRNA
In short: Vaccines began with Edward Jenner's cowpox experiment in 1796 and now include mRNA technology. Immunisation prevents an estimated 3.5–5 million deaths every year worldwide.
Jenner and variolation
Before vaccines, people in Asia, Africa and the Ottoman Empire practised variolation — deliberate exposure to mild smallpox material. In 1796 Edward Jenner showed that cowpox protected against smallpox. The word 'vaccine' comes from vacca, Latin for cow.
The vaccine century
The 20th century produced vaccines for diphtheria, tetanus, pertussis, polio (Salk 1955, Sabin oral vaccine 1961), measles (1963), mumps, rubella and hepatitis B. WHO launched the Expanded Programme on Immunization (EPI) in 1974.
Immunisation in Nepal
Nepal began its national immunisation programme in 1979. It has since added vaccines such as hepatitis B, Hib, PCV, rotavirus, measles-rubella, Japanese encephalitis and HPV. Nepal was certified polio-free with the WHO South-East Asia Region in 2014 and was verified as having eliminated maternal and neonatal tetanus.
The mRNA era
COVID-19 mRNA vaccines, authorised in late 2020, were developed in under a year thanks to decades of earlier research. The 2023 Nobel Prize in Medicine went to Katalin Karikó and Drew Weissman for the discoveries that made them possible.
Key takeaways
- Jenner's 1796 work began the vaccine era.
- Nepal's national immunisation programme started in 1979.
- mRNA platforms allow much faster vaccine development.
Common questions
Are vaccines safe?
Licensed vaccines undergo clinical trials and continuous safety monitoring. Serious side effects are rare and the benefits far outweigh the risks.
How many deaths do vaccines prevent?
WHO estimates 3.5–5 million deaths are prevented every year.
References
Educational content by PHC-Nepal. It does not replace advice from a qualified health professional.