RFK Jr.’s rejection of germ theory debunked in Senate hearing - Ars Technica

In a Congressional hearing on Wednesday, Sen. Bernie Sanders (I-Vt.) directly confronted anti-vaccine Health Secretary Robert F. Kennedy Jr. on his rejection of germ theory—the unquestionable scientific idea that specific pathogenic microbes cause specific diseases. After Kennedy defended his fringe view, Senator Bill Cassidy fact-checked and debunked Kennedy’s denialist arguments in real time.

The exchanges mark a rare instance in which Kennedy’s dismissal of germ theory has been raised in such a high-profile public setting, in this case, a hearing of the Senate Committee on Health, Education, Labor, and Pensions. Kennedy, who has no background in science, medicine, or public health, is well known as an ardent anti-vaccine activist and peddler of conspiracy theories. But his startling rejection of a cornerstone theory in biomedical science has mostly been underreported.

As Ars Technica reported last year, Kennedy wrote about his germ theory denialism explicitly in his 2021 book The Real Anthony Fauci. In it, Kennedy maligns germ theory as a tool of pharmaceutical companies, scientists, and doctors to promote the use of modern medicines. Instead of accepting germ theory, Kennedy promotes a concept akin to the discarded terrain theory, in which diseases stem not from germs, but from imbalances in the body’s inner “terrain.” Those imbalances are claimed to be caused by poor nutrition and exposure to environmental toxins and stressors. (In his book, Kennedy erroneously labels this as “miasma theory,” but that is a different theory that suggests diseases derive from breathing bad air, vapors, or mists from decaying or corrupting matter. The idea was supplanted by germ theory, while terrain theory was never widely accepted.)

Kennedy’s embrace of terrain theory over germ theory is foundational to the priorities of his Make America Healthy Again (MAHA) movement, which promotes notions of healthy diets and lifestyles and clean living. As health secretary, Kennedy has focused on revamping federal dietary guidance, focusing on whole foods (and concerning amounts of saturated fat) while vilifying artificial ingredients and additives. He has regularly posted videos of himself working out on social media. And, with his previous career as an environmental lawyer, he has a long history of fighting against environmental contamination. Kennedy and his MAHA movement have strongly lobbied against chemical pollutants and pesticides, particularly glyphosate (though Kennedy notably shifted on this issue recently, and now supports increasing production of the weed killer, in line with Trump’s policies).

As Kennedy describes in his book, his preferred theory “emphasizes preventing disease by fortifying the immune system through nutrition and by reducing exposures to environmental toxins and stresses,”—not using vaccines or advanced medicines to fight off specific pathogens as suggested by germ theory.

While no respected health expert would argue against the benefits of a healthy diet and an environment free of toxic substances, this does not negate the reality that obligate pathogens, with evolved and specialized molecular weaponry to invade and ravage their victims, cause specific diseases. Still, Kennedy disparages germ theory and attempts to undermine it with shaky arguments.

In the hearing on Wednesday, Sanders called attention to Kennedy’s denial of germ theory while raising one of Kennedy’s shaky arguments for debunking. In opening statements, Sanders warned Kennedy that he wanted to question the “things that you have written which call in doubt the very existence of the germ theory.”

During his questioning, Sanders referenced a passage in Kennedy’s book that reads:

A doctrinal canon of the germ theory credits vaccines for the dramatic declines of infectious disease mortalities in North America and Europe during the twentieth century. … Most Americans accept this claim as dogma. It will therefore come as a surprise to learn that it is simply untrue.

Sanders pointed out a 2024 study led by the World Health Organization and published in The Lancet that found that since 1974, vaccines had saved an estimated 154 million lives, including 146 million children under the age of 5—or, as WHO put it, vaccines saved the equivalent of six lives every minute of every year over the past 50 years.