As reported by the Chicago Daily News, sister paper of the Chicago Sun-Times:
Modern doctors would applaud the “physicians who ha[d] made considerable use of anti-influenza bacterin (vaccine) in the treatment of influenza” in 1919, who believed “that the bacterin is a very effective preventative and also a valuable remedy for influenza,” the Daily News reported in its Jan. 21, 1919 edition.
Chicagoans of that era, however, were suspicious of the flu vaccine’s effectiveness, as the article notes. They had good reason to be — but not because vaccines are ineffective.
Physicians of 1919 believed the flu was caused by bacteria, not a virus. Their vaccines treated bacterial infections that produced pneumonia-like symptoms while not actually treating the flu virus.
Chicagoans were in the middle of a pandemic and would have been skeptical of so many vaccines that appeared to work. “We have been victimized so often, in medical life, by medical enthusiasts whose discoveries seem to epochal at first flush and peter out so discouragingly on more sober investigation,” the reporter lamented.
