"The development of effective vaccines is a crucial step in controlling infectious diseases."

"My only object has been to give the most complete description of the bacilli as they appear in the human body and in cultures."

"The time has come when we can look forward to the eradication of tuberculosis."

"I have always been fascinated by the invisible world of microbes."

"As long as we do not know the cause of a disease, we can do nothing for its prevention."