Fact Check-A meningitis vaccine trial at a U.S. military camp did not cause the 1918 Spanish Flu

An article shared over 60,000 times on Facebook attributes the deadly 1918 pandemic known as the “Spanish Flu” to a “massive military vaccination experiment” in Fort Riley, Kansas. While a meningitis vaccine trial did take place, experts contacted by Reuters said a meningitis vaccine could not have caused a flu pandemic. The H1N1 virus that caused the 1918 flu has been identified and replicated by scientists. The meningitis vaccine was designed to tackle a specific bacteria (meningococcus) and a completely different disease.

An article entitled “The 1918 “Spanish Flu”: only the vaccinated died” (archived here ) has been shared over 61,119 times on Facebook since its publication May 29, 2020 (according to CrowdTangle data). It continues to be shared on social media as of April 9, 2021 ( here , here ). Some Facebook users have shared a screenshot of the headline of the article, as can be seen here .

It says the initial outbreak of the disease and subsequent deaths caused by the pandemic, which infected an estimated one third of the world’s population between 1918 and 1920 ( here ), were caused by a military experiment of a “bacterial meningitis vaccine” and not by a “flu at all”. This fact-check article aims to explain why this central claim is false; Other claims made in the article are out of scope of this article.

It is true that in early 1918, before the first cases of Spanish flu were reported at Camp Funston at Fort Riley in Kansas in March 1918 ( here ), a trial of a vaccine made with inactivated strains of the meningococcus bacteria ( here ) was conducted on military volunteers at the same location.

According to a report published in July 1918 by Frederick L. Gates, First Lieutenant of the Medical Corps, U.S. Army ( here ), the experimental vaccine created in the laboratory of The Rockefeller Institute was given to “about 3,700 volunteers” and the doses “rarely caused more than the mildest local and general reactions”, which included “headache, joint pains, and nausea” and in some cases, diarrhea.

However, “there would be no way that a meningitis vaccine could contribute to starting a flu epidemic,” Dr Donald Burke, epidemiologist and former dean of the University of Pittsburgh Graduate School of Public Health ( here ), told Reuters via phone.

“Meningitis is a different disease, caused by a type of bacteria. It is not genetically or closely related to influenza”, Burke explained. “Influenza is a virus, a much smaller microbe than a bacteria; they are entirely different kinds of microorganisms that cause entirely different kinds of diseases.”

Stephen Kissler, Postdoctoral Fellow of Immunology and Infectious Diseases at Harvard T.H. Chan School of Public Health ( here ) told Reuters via phone that the vaccine used at Camp Funston “was derived from existing meningitis strains” that were potentially inactivated with heat. He saw no reason to conclude a vaccine, which was made with existent, inactivated strains of meningitis bacteria from people who had previously been sick with meningitis, had "caused a major epidemic."

As explained here the Office of Medical History of the U.S. Army Medical Department, meningococcal meningitis, which causes inflammation around the surrounding tissues of the brain ( here ), "has always been one of the most serious and important of the various communicable diseases of man” among soldiers. “It becomes more common when young people are together in closed quarters like dormitories or barracks,” so “the military had a good reason to test a vaccine against meningitis,” Burke said.

It was also not rare to research and test vaccines at this time in history given it was an “early era of microbiology,” Burke added. “The Fort Riley meningococcal vaccine experiment was not an unusual scientific undertaking” and “Many [bacterial] vaccine trials were going on all over the U.S. around 1918.”

The article “The State of Science, Microbiology, and Vaccines Circa 1918” by John M. Eyler provides more context ( here ). For example, during the 1918 flu pandemic itself, experimental bacterial vaccines for influenza were used in army camps as well as on workers, including 275,000 employees of the U.S. Steel Company ( here , here , here ). The cause of the pandemic was unknown at the time, explaining why bacterial vaccines were being tested in the hopes they might work on this new deadly disease.

The claim made in the article shared on social media that “autopsies after the war proved that the 1918 flu was NOT a ‘flu’ at all” but was caused by the “bacterial meningitis vaccine” is also baseless.

It links to an article published in NewScientist entitled: “Bacteria were the real killers in 1918 flu pandemic” ( here ). As previously explained by a Reuters Fact Check here , evidence has shown that a vast majority of those who died during the 1918 pandemic did not die of influenza alone but of bacterial pneumonia contracted as a result of the influenza virus ( here ).

“The people generally would not have died from the bacterial infection if their lungs have not already been attacked by this virus,” Kissler explained. This secondary infection that follows “takes advantage of the damage that had been done by the virus.”

Finally, experts pointed out that evidence gathered over the decades since has conclusively proven that the 1918 pandemic was caused by an H1N1 virus. Further reading about the discovery and reconstruction of the H1N1 virus can be found here .

“The work done by Dr. Jeffrey Taubenberger and his team at NIH (National Institutes of Health) over the last several decades has conclusively proven that the 1918 pandemic was indeed caused by A/H1N1 influenza,” Alex Navarro, Assistant Director at the Center for the History of Medicine of the University of Michigan, told Reuters via email.

“They have obtained tissues samples from the period and have sequenced the genome. Full stop. It was A/H1N1 that caused the world’s deadliest pandemic in history,” Navarro added.

Finally, according to Kissler, the evidence is substantiable that the 1918 pandemic was caused by a flu strain. “I don’t see any component reason to believe it was anything else.”


False. According to experts, a 1918 meningitis vaccine trial in Kansas, where months later the first cases of the Spanish Flu were reported, could not have contributed to start the Spanish Flu pandemic. The H1N1 virus that caused the deadly pandemic has since been identified and replicated by scientists.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts here  .