FactCheckRadar Fact-check archive

Published fact-check

RFK Jr. Faces Backlash Over Claims That Polio Vaccines Killed More People Than the Disease

Contradicted

Claim checked

“RFK Jr: The polio vaccine “killed many, many more people” than polio ever did. Fact check : Weapons grade horse”

Published

How it works

This report was created by FactCheckRadar chrome extension. Click here to get early access.

Verdict

Contradicted

The claim that the polio vaccine "killed many, many more people" than polio ever did is contradicted by historical health data and decades of medical surveillance.

While Robert F. Kennedy Jr. has specifically pointed to the presence of the SV40 virus in early vaccine batches as a source of mass cancer deaths, extensive global studies have found no evidence of increased cancer rates among recipients. In contrast, polio was a devastating disease that paralyzed tens of thousands and killed thousands of Americans annually before the vaccine led to its near-elimination.

7 reviewed sources behind this verdict.

Reasoning

The verdict is based on a comparison between the documented impact of the polio virus and the safety record of the vaccine.

  • Impact of Polio: Before the vaccine, polio was a major public health crisis. In 1952 alone, a single outbreak in the U.S. killed 3,000 people and paralyzed 20,000.
  • The SV40 Controversy: RFK Jr.'s claim relies on the fact that early polio vaccines (late 1950s to early 1960s) were contaminated with Simian Virus 40 (SV40). While SV40 was found to cause tumors in lab hamsters, multiple long-term studies involving millions of people in the U.S., U.K., Germany, and Sweden found no difference in cancer rates between those who received the contaminated vaccines and those who did not.
  • Vaccine Success: Since the introduction of the vaccine, polio cases in the U.S. dropped from thousands per year to zero by 1979.

RFK Jr. has a documented history of making these claims, notably during a 2023 appearance on Lex Fridman's podcast, where he alleged an "explosion" of soft tissue cancers. However, medical experts like Dr. Paul Offit note that these claims are based on a "scare that didn't pan out" and are not supported by the 15-year and 35-year follow-up studies conducted by public health officials.

Source quality: The evidence includes detailed historical data on polio mortality, specific scientific explanations of the SV40 contamination from medical experts (Dr. Paul Offit), and reporting from reputable outlets like The Atlantic and Al Jazeera regarding the current political and medical consensus.

Key checks

  • Comparison of Polio Deaths vs. Vaccine Risks: Historical data shows polio killed 1,500 to 3,000 people annually in the U.S. during peak years. In contrast, long-term studies of the SV40-contaminated vaccines showed no statistically significant increase in cancer deaths among the 98 million recipients.

  • Scientific Consensus on SV40 and Cancer: While SV40 is carcinogenic in hamsters, more than a dozen studies have confirmed it did not cause cancer in humans who received the early Salk or Sabin vaccines.

  • RFK Jr.'s Public Statements: RFK Jr. explicitly claimed on the Lex Fridman podcast in July 2023 that the vaccine caused an 'explosion' in cancers that killed 'many, many, many' more than polio.

Confidence

High

Was this useful?

Your vote helps us see which fact-checks deserve more attention.