Vaccines and the flu virus of 1918–1919

In 1918, with the world in the grippe’s grasp, researchers were desperate for a way to stem the pandemic. They turned to new vaccines, all of which mistakenly targeted bacteria instead of viruses, said John Eyler, Ph.D., a medical historian at the University of Minnesota who gave the George Rosen Memorial Lecture at the Beaumont Medical Club in February. Medical journals and the lay press touted the vaccines’ efficacy even though experts—including the American Public Health Association (APHA)—harbored doubts.

By 1919, “the tide of professional opinion began to change” about the accuracy of the results, said Eyler. In retrospect it became clear that the early trials were rife with problems: poor selection criteria leading to biased samples and “no concern about who was a proper subject,” Eyler said.

“American physicians certainly were inexperienced at conducting trials,” Eyler said. They conducted them when the nation was “desperate” for relief from the pandemic, but the profession had no standards for what constituted an adequate vaccine trial.

The APHA established stricter standards for vaccine trials in 1919, though randomized trials wouldn’t become common practice until decades later.