In 1879, Pasteur’s aged bacteria showed that weakened microbes could protect against disease
TIMESOFINDIA.COM / Jun 07, 2026, 17:55 (IST)
Louis Pasteur's 1879 chicken cholera experiments, though often simplified, revealed a crucial principle: weakened pathogens can train the immune system. This scientific breakthrough, not a mere accident, revolutionized vaccine development, shifting it from natural observation to deliberate laboratory science. His work laid the foundation for modern vaccines, proving pathogens could be attenuated to induce immunity.