The Claim:
This myth about COVID vaccines keeps coming back to us, with one of the most circulated tweets of the year claiming that ivermectin is the cure. At their root, these myths claim that COVID mRNA vaccines cause cancer by altering the immune system, integrating synthetic DNA, or containing harmful contaminants that increase cancer risk over time.
The Facts:
These stories take advantage of people’s concerns about new medical technology, confusion about how the immune system and genetics work, and distrust of health officials. They use complicated scientific language, emotional stories, and personal experiences to seem believable, even though they don’t have strong scientific proof.
Some claims about COVID vaccines causing cancer are based on misunderstandings of vaccine components. For example, a segment of DNA, called a promoter, associated with the simian virus SV40, which was linked to early polio vaccine contamination, has been used in vaccine manufacturing to help produce the antigens found in the vaccines. Manufacturing processes ensure its removal, and no credible studies link COVID vaccines to cancer through SV40 DNA. Claims that vaccine vials contained unsafe levels of DNA come from expired, improperly stored samples, making the results unreliable. Importantly, mRNA vaccines are not gene therapy and cannot alter human DNA.
The idea that COVID vaccines cause “turbo cancer” has no scientific backing. Even the most potent carcinogens take years to cause cancer, making claims of sudden cancer spikes implausible. Epidemiological data show no increase in cancer linked to the vaccines. Reports of rising early-onset cancers started in the 1990s, long before the COVID vaccines existed.
Misinterpretations of scientific studies also fuel vaccine-related cancer claims. For example, a German study on children’s immune responses after COVID vaccination found an increase in IgG4 antibodies, which some falsely linked to cancer. However, the study did not mention cancer or immune system damage. Its findings showed that vaccinated children had mild or no symptoms when infected with COVID, indicating the vaccine’s effectiveness. These claims reflect misinformation rather than scientific reality.
Read more of our posts debunking claims about COVID vaccines and cancer.
Disclaimer: Science is always evolving and our understanding of these topics may have evolved too since this was originally posted. Be sure to check out our most recent posts and browse the latest Just the Facts Topics for the latest.
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