BCG vaccine
Calmette and Guérin publish early tuberculosis-vaccination research
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Original prompt & settings (JSON) ↗The year 1906 marks a paper and possibly the first ox-bile experiments. No child received BCG until 1921.
What 1906 actually produced
In 1906 Albert Calmette and Camille Guérin published early work titled "Sur la vaccination contre la tuberculose par les voies digestives" — on vaccination against tuberculosis by the digestive routes.
They were studying whether exposure to living bovine tubercle bacilli could protect cattle, and whether administration through the digestive tract could produce immunity.
Some modern histories also place the first treatment of Mycobacterium bovis with ox bile in 1906, describing the altered appearance of the cultured bacilli as the start of BCG development. Bile was initially useful because the bacteria clumped together.
Years of passage, not a year of discovery
No finished human BCG vaccine existed or was administered in 1906. The attenuated strain came out of repeated passage, with transfers to fresh culture roughly every three weeks, reaching 230 passages by 1920.
The first human use came in 1921.
Edmond Nocard had supplied Guérin with the bovine tuberculosis culture from which the BCG lineage ultimately descended.
Which year counts depends on the definition
"First developed" has no single defensible date. Sources variously identify early research in 1900, vaccination publications or bile experiments in 1906, continuous attenuation from 1908, an innocuous strain after years of passage, and first human use in 1921.
The Institut Pasteur and a major microbiological review date the decisive culture and continuous serial-attenuation programme to 1908, with derivation of the original BCG strain spanning 1908–1921.
The discrepancy reflects competing definitions of "development," not a one-day discovery.
Sources
Researched 23 Aug 2026 5 sources 2 audit passes Date disputed
How this was checked
Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →
Date disputed. Sources disagree about when this happened.
What the sources leave uncertain
- “First developed” has no single defensible date. Sources variously identify early research in 1900, vaccination publications or bile experiments in 1906, continuous attenuation beginning in 1908, an innocuous strain after years of passage, and first human use in 1921.
- The Institut Pasteur and ASM date the decisive M. bovis culture/passaging program to 1908, while a recent historical review and an older WHO milestone identify 1906. The discrepancy reflects different definitions of “development,” not a one-day discovery.
- Because only a year is supplied and no discrete event is defined, this should not be written as a conventional “on this day” article.