Which scientist confirmed the germ theory of disease?

The germ theory of disease, which posits that microorganisms are the cause of many diseases, was significantly advanced by Louis Pasteur. He conducted critical experiments that demonstrated how germs could lead to spoilage and disease, notably with his studies on fermentation and spoilage of beverages. Pasteur's work laid the foundation for understanding how diseases are transmitted, including the development of methods for sterilization and vaccination.

His notable experiments with swan-neck flasks showed that microorganisms from the air were responsible for contamination, challenging the then-prevailing ideas about spontaneous generation. Pasteur's contributions were paramount to establishing that specific pathogens are linked to specific diseases, thus confirming the germ theory.

While Robert Koch also played a significant role by developing a systematic method for identifying the bacteria that caused specific diseases, it was Pasteur's foundational work that led to the acceptance of germ theory in the scientific community. Other notable figures like Edward Jenner focused primarily on vaccination and the immune response, while Joseph Lister is celebrated for his advancements in surgical hygiene, which stemmed from germ theory principles, but it was Pasteur who primarily confirmed and popularized the germ theory itself.