News

RFK Jr. has suggested vaccines caused 1918 Spanish flu pandemic at least twice

Kennedy made the claim at least twice during his 2024 presidential election campaign.

by Caroline Wazer, Published April 1, 2025


Image courtesy of Getty Images/Snopes illustration


For years, internet users have shared a rumor about U.S. Health Secretary Robert F. Kennedy Jr. falsely claiming that vaccines caused the 1918-1919 influenza pandemic known as the Spanish flu.

One Facebook post (archived) with around 105,000 reactions at the time of this writing featured a photo of Kennedy with the caption:

This pathetic moron claims the 1918 flu pandemic was caused by flu vaccines. The first flu vaccine was introduced in the 1930s and they weren't widely available until the 50s.

This is the idiot the Orange Buffoon put in charge of our Department of Health and Human Services.

(Facebook page Occupy Democrats)

Examples of the claim also appeared in posts on social media platforms including X (archived), Threads (archived) and Reddit (archived), as well as in reporting by The New York Times and Rolling Stone.

Snopes readers searched our site and wrote messages to the newsroom asking if Kennedy really said vaccines, or vaccine research, caused the 1918 pandemic that killed an estimated 50-100 million people worldwide, according to a 2002 estimate (a more recent estimate in 2018 placed the death toll lower at around 17.4 million).

In short, on at least two occasions — in June 2023 and June 2024 — Kennedy said he had read what he described as "strong" and "good" evidence linking the 1918 influenza outbreak to vaccine research. However, he also noted he did not think the evidence was "definitive" and said that "we'll probably never know" if vaccine research caused the pandemic.

Kennedy did not specify what evidence he meant. However, based on a comment about "testing a new vaccine in Kansas" in one of the instances linking vaccines to the 1918 flu, it seemed likely he was referring to a debunked conspiracy theory about meningitis vaccines — not flu vaccines — supposedly causing the outbreak.

We've reached out to Kennedy to ask for details about the alleged "evidence" and will update this story if and when we hear back.

Here's what Kennedy said

First, on June 27, 2023, Kennedy brought up what he described as "very, very strong articles" linking the 1918 pandemic to vaccine research during a health policy-focused Zoom roundtable organized by his 2024 presidential campaign.

Kennedy made the comment around the 31:48 mark in the video embedded below, just after he outlined how, as president, he would prioritize funding research into chronic rather than infectious diseases and end gain-of-function research (research that involves altering how organisms, including disease-causing microbes like viruses, function).

After describing those goals, Kennedy said (emphasis ours):

Everything from Lyme disease to COVID, and many many other diseases, like RSV, which is now one of the biggest killers of children, came out of, you know, a vaccine lab, and we can go down the whole list of diseases. There's good evidence that even Spanish flu came from vaccine research, and you know, we don't know, and we'll probably never know, but, you know, there are very, very strong articles suggesting that now.

Around a year later, Kennedy repeated the notion during a June 15, 2024, appearance on Joe Rogan's podcast. Kennedy's remarks about the alleged "evidence" linking vaccine research to the 1918 pandemic began around the 1:53 mark in the video embedded below, just after he and Rogan discussed their shared belief in the inefficacy of vaccines.

Kennedy said (emphasis ours):

There's good evidence that the Spanish Flu — there's, you know, not definitive but very very strong evidence the Spanish Flu was vaccine-induced flu, the deaths were vaccine-induced. Originally they said it was a flu but when they've gone back and actually they have all the samples from thousands of people, they died from bacteriological (sic) pneumonia.

Kennedy then brought up a 2008 article that Anthony Fauci, who served as U.S. President Donald Trump's chief medical adviser in 2021 and 2022, cowrote. That article, which we'll discuss in further detail below, examined the prevalence of secondary bacterial infections among victims of the 1918 pandemic.

Kennedy returned to the false notion that vaccines caused the pandemic around the 1:54:54 mark in the video above, saying, "The article that I read made a very strong case that the illness came from testing a new vaccine at a military base in Kansas, and again I'm a little hazy on the detail …"

Rogan and Kennedy then went back to discussing the 2008 article by Fauci and his coauthors, which did not mention any theory about vaccines supposedly causing the pandemic.

A debunked conspiracy theory

In his comments both in the podcast episode and Zoom webinar, Kennedy did not elaborate on the alleged "evidence" supposedly connecting the 1918 flu pandemic to vaccine research. 

In other words, it was not clear what type of vaccine he believed may have been responsible for the outbreak. Some internet users assumed he meant a flu vaccine — something that did not exist until decades after the 1918 pandemic, as some social media posts linked above correctly pointed out.

In the Rogan interview, Kennedy's mention of a Kansas military base suggested he was referring to a debunked conspiracy theory involving a vaccine to prevent bacterial meningitis. According to that theory, the 1918 pandemic was the result of a meningitis vaccine that medical officers distributed to soldiers at Camp Funston, a Kansas military camp, in fall 1917.

That conspiracy theory spread in 2020 due to an article by chiropractor Sal Martingano. In that article, titled "The 1918 'Spanish Flu': Only The Vaccinated Died," Martingano claimed that "the 1918 flu was NOT a 'FLU' at all," but that the disease "was caused by random dosages of an experimental 'bacterial meningitis vaccine', which to this day, mimics flu-like symptoms.

It's unknown if Kennedy came across the theory about the 1918 pandemic origin via Martingano's article or another way, but as Reuters and History of Vaccines (a project of The College of Physicians of Philadelphia) have pointed out, Martingano's argument was full of misleading and outright incorrect information.

For example, to raise suspicions about the pandemic's origin, Martingano asserted that autopsies showed the pandemic's victims did not have influenza at all. That was false.

It's true, as Fauci and his coauthors noted in the 2008 article, that many of the people who lost their lives during the pandemic technically died from secondary bacterial infections — a common phenomenon in outbreaks of viral diseases. A press release about Fauci's article quoted him explaining:

"The weight of evidence we examined from both historical and modern analyses of the 1918 influenza pandemic favors a scenario in which viral damage followed by bacterial pneumonia led to the vast majority of deaths," says co-author NIAID Director Anthony S. Fauci, M.D. "In essence, the virus landed the first blow while bacteria delivered the knockout punch."

In other words, while many of the pandemic victims officially died from pneumonia, claims that these individuals did not have influenza were false. Over email, Michael Worobey, a professor in ecology and evolutionary biology at the University of Arizona, described Martingano's theory as "incorrect," writing:

We have remarkably clear evidence that the pandemic was caused by an influenza virus, specifically a subtype H1N1 influenza A virus. In fact genetic material from this virus has been recovered by scientists from numerous autopsy tissues from victims of the 1918 flu.

Researchers first extracted viral genetic material from the remains of a victim in 1997, and scientists have subsequently recovered additional samples of the virus from other victims. That evidence definitively proves the pathogen behind the pandemic was the H1N1 subtype of the influenza A virus.

Notably, Martingano falsely stated the 1918 pandemic was the result of soldiers at Kansas' Camp Funston receiving experimental vaccines for bacterial meningitis. 

It's true, according to a report from an Army medical officer published in the Journal of Experimental Medicine in 1918, that some soldiers at Camp Funston voluntarily took meningitis vaccines in October and November 1917, several months before records show people at the camp fell ill with the flu at the center of the 1918 pandemic (that happened in March 1918).

Although researchers continue to debate the outbreak's starting location, there's evidence that the strain of flu that caused the pandemic was already in circulation before the cases at Camp Funston — just not at a level that attracted significant attention at the time.

For example, in 2004, historian and pandemic researcher John M. Barry argued that the real origin site was not Camp Funston but around 270 miles southwest in Kansas' Haskell County, where people suffered from a severe type of influenza in January and February 1918.

Some researchers have suggested that the flu strain was present in the U.S. or other countries even earlier. In a 2019 article published in the peer-reviewed journal Evolution, Medicine, and Public Health, coauthors Worobey, Jim Cox and Douglas Gill cited a February 1918 flu outbreak in New York City that may have been caused by the same viral strain that led to the pandemic.

Other researchers have argued that outbreaks of flu-like respiratory diseases in China, France or other countries in as early as 1915 marked the true beginning of the pandemic. (The exact cause of those outbreaks remains uncertain.)

The rumor about Kennedy suggesting the 1918 pandemic was the result of vaccine research was not his first questionable statement about viruses that we've investigated. We previously looked into the claim that Kennedy said COVID-19 was targeted to "spare" Jewish and Chinese people.


By Caroline Wazer

Caroline Wazer is an assignments editor based in Central New York. She has a Ph.D in history.


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