COVID-19 Vaccines May Be Causing Cancer, Experts Say

Doctors testified at a Senate hearing about their experiences.

Published: 6/4/2026, 2:45:01 PM EDT

COVID-19 Vaccines May Be Causing Cancer, Experts Say — A COVID-19 vaccine being administered in Illinois on Sept. 9, 2022. (Scott Olson/Getty Images)

COVID-19 vaccines may cause cancer in some people, doctors said June 3.

Dr. Angus Dalgleish, professor emeritus of oncology at the University of London, told a hearing in Washington that he witnessed patients unexpectedly develop cancer after receiving COVID-19 vaccines built with messenger ribonucleic acid (mRNA) technology.

“I have no doubt in my mind that the mRNA vaccine likely played a significant role in the development of these unexpected cancers,” he said.

Dr. Wafik El-Deiry, director of Brown University's Legorreta Cancer Center, said during the hearing that he has found the spike protein, found in both COVID-19 and COVID-19 vaccination, could reduce the ability to activate genes involved in suppressing cancer. El-Deiry and a colleague in a January paper listed dozens of publications describing different types of cancer appearing shortly after COVID-19 vaccination or infection, several months after they told a federal vaccine committee that safety issues with the vaccines could include cancer, with cancer mechanisms being one of the areas that needed further exploration.

That committee advised the Centers for Disease Control and Prevention to scale back recommendations for COVID-19 vaccination. The CDC did so, but that update was blocked in March by a federal judge. An appeal is pending.

"Looking at the totality of up-to-date evidence, and what you've heard from eminent witnesses today, in my view, millions of Americans, and millions more across the world, may be in clear and present danger of suffering premature cardiovascular disease and cancer,” Dr. Aseem Malhotra, a British cardiologist, said during the hearing on Wednesday.

Sen. Ron Johnson (R-Wis.), chairman of the Senate Permanent Subcommittee on Investigations, hosted the hearing.

Johnson, a frequent critic of COVID-19 vaccines, said it was important not to wait for definitive proof to warn the public about possible dangers associated with the vaccines.

Sen. Richard Blumenthal (D-Conn.), the top Democrat on the subcommittee, noted how the National Cancer Institute quotes Dr. Steven Pergam, with the Fred Hutchinson Cancer Research Center, as saying “there is no evidence that COVID-19 vaccines cause cancer, lead to recurrence, or lead to disease progression.”

Dr. Julie Gralow, chief medical officer of the American Society of Clinical Oncology, called by Blumenthal to testify during the hearing, said that “currently there is no clinical evidence proving mRNA COVID-19 vaccines cause cancer or accelerate cancer growth.”

Gralow said it was important to research the possibility but said that reports describing cancers being found shortly after COVID-19 vaccination did not mean vaccination caused the cancers, because it was unclear when the cancers developed.

Pfizer and Moderna, which manufacture mRNA COVID-19 vaccines, did not return requests for comment by time of publication.

From The Epoch Times