False Claims Link COVID-19 Vaccines to Cancer, Despite Scientific Evidence
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Despite evidence demonstrating the life-saving benefits of COVID-19 vaccines – preventing an estimated 1.4 million deaths in Europe alone, according to the World Health Organization – unsubstantiated claims linking the vaccines to an increased risk of cancer are resurfacing. As France prepares its winter vaccination campaign, a recent wave of misinformation, amplified by controversial scientist Didier Raoult, is being debunked by medical professionals and fact-checkers.
Raoult Revives Discredited Claims
Didier Raoult, a Marseille-based scientist previously known for his promotion of unproven COVID-19 treatments like hydroxychloroquine and his skepticism towards vaccines, recently shared two studies on X (formerly Twitter) that he claimed demonstrated a link between COVID-19 vaccination and cancer. He alleged a 37% increase in cancers overall among vaccinated individuals, and a particularly alarming 157% increase in pancreatic cancers among those who received two vaccine doses.
However, these claims are demonstrably false. Experts emphasize that the authors of the cited studies do not draw these conclusions, and the research itself is riddled with methodological flaws. AFP Fact Check has previously addressed similar misinformation on this topic here and here.
Methodological Weaknesses Undermine Study Validity
One study cited by Raoult, published in the journal Excli Journal in July 2025, examined data from nearly 300,000 people in Italy. While the study observed a higher risk of mortality in all causes combined among vaccinated individuals, the authors themselves acknowledge the findings are preliminary and potentially influenced by selection bias.
“Vaccinated people were, on average, older and had more pre-existing health conditions – such as hypertension and diabetes – than unvaccinated individuals,” explains cancerologist Jérôme Barrière. “This means the vaccinated group was inherently more vulnerable, and therefore more likely to experience serious health outcomes, including cancer, regardless of the vaccine’s impact.” Furthermore, the study revealed a significantly higher prevalence of existing cancer diagnoses within the vaccinated group (4.2% vs. 2.3% in the unvaccinated group), further confounding the results. “This creates a confusion effect,” Barrière states, “observing more cancer hospitalizations in the vaccinated group doesn’t necessarily mean the vaccine caused the cancer.”
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Korean Study Faces Similar Scrutiny
Raoult also referenced a South Korean study published in Biomarker Research in September 2025, which reported “associations” between COVID-19 vaccination and an increased risk of six cancer types. However, the study’s authors explicitly state that their findings do not establish a causal relationship. They emphasize the need for further research to “elucidate potential causal relationships.”
Barrière points out several critical limitations. Firstly, a one-year follow-up period is insufficient to detect vaccine-induced cancers, as cancer development typically takes much longer. Secondly, the study’s findings may be attributed to detection bias – vaccinated individuals are more likely to be in contact with the healthcare system and therefore more likely to receive a cancer diagnosis. Researchers commenting on the study on Pubber, a scientific article discussion site, also highlighted that the six cancer types identified in the study are those routinely screened for in South Korea, suggesting a detection explanation is more plausible than a causal one.
Raoult’s History and Recent Sanctions
This latest episode of misinformation comes after Raoult was prohibited from practicing medicine for two years, beginning February 1, 2025, due to violations of public health code, specifically for promoting hydroxychloroquine as a COVID-19 treatment without reliable scientific evidence. His previous research, including a foundational study published in the Journal of Antimicrobial Agents in March 2020, was invalidated in December 2024 by the journal’s publisher due to non-compliance with research standards and problematic interpretation of results.
The spread of Raoult’s claims was further amplified when they were repeated on the French television show “All beautiful all n9uf” on October 7, 2025, without presenting opposing viewpoints.
Experts Condemn Misinformation
The resurgence of these claims has drawn swift condemnation from health professionals. Professor Mathieu Molimard, President of the French Society of Pharmacology and Therapeutics, labeled the information “Fake News” and warned that such disinformation is “dangerous” and can deter people from essential vaccinations. He tagged the audiovisual regulator, the Arch, in his X post.
Barrière similarly refuted any link between COVID-19 vaccines and cancer, stating that the studies “do not show any correlation” and have a “fairly weak” level of evidence. Raoult did not respond to requests for comment from AFP.
A collective of fifty cancerologists, including Barrière, previously refuted similar claims in March 2023, stating that no epidemiological data supports a link between COVID-19 vaccination and cancer risk. They reiterate that there has been no “statistical burst” in cancer cases observed in epidemiological studies.
Upcoming Vaccination Campaign
France’s new COVID-19 vaccination campaign is scheduled to begin on October 14, 2025, alongside the annual flu vaccination drive. Approximately 19 million individuals deemed at high risk of severe illness from respiratory infections – including those over 65, individuals with chronic conditions, and pregnant women – are eligible for free influenza vaccines. The COVID-19 vaccine remains fully reimbursed for all French citizens.
