Claim: The COVID-19 vaccine weakens the p53 gene, also known as the tumor suppressor gene, increasing the risk of cancer.
Rating: FALSE
Why we fact-checked this: The claim was made in a Facebook reel with 7,100 plays, 305 reactions, and 26 comments as of writing. The video, which bears the text, “Expose natin kung san nanggaling ang cancer ni Doc Willie Ong” (Let’s reveal where Doc Willie Ong’s cancer came from), claims a causal link between cancer and the COVID-19 vaccine.
The video was posted a few days after Ong, a cardiologist and online health personality, revealed he was diagnosed with cancer.
The facts: There is no evidence that COVID-19 vaccines cause cancer. Similar posts, which circulated as early as 2022, have been debunked multiple times by AFP Fact Check in 2022, 2023, and 2024 and by Science Feedback in 2024.
According to the New York City-based Memorial Sloan Kettering Cancer Center, the COVID-19 vaccine cannot cause cancer or “inactivate the genes that suppress tumors.”
This is also supported by the US National Cancer Institute (NCI), which states that there is no evidence that the vaccine “causes cancer, leads to recurrence, or leads to disease progression.”
COVID-19 vaccines and the p53 gene: These claims are based on a study conducted by Shengliang Zhang and Wafik S. El-Deiry, oncologists from Brown University. The study found that spike proteins in COVID-19 vaccines affect the p53 gene. The p53 gene “helps regulate normal cell growth and multiplication,” and changes in this gene may “cause cancer cells to grow and spread in the body,” according to the NCI.
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The Facebook reel claims that the COVID-19 vaccine could promote tumor growth because it weakens the p53 gene and consequently the body’s ability to suppress cancerous mutations. However, the study does not say this.
In a post on X (formerly Twitter) page, El-Deiry stated that the study does not provide proof that the COVID-19 vaccine causes cancer, and that such a conclusion is “overinterpreting preliminary data and is misinformed.”
“Cancer is a complex disease that takes time to develop and cancer causing viruses take years to “cause” cancer. The proof of causality takes much more work and different types of evidence,” El-Deiry said, adding that more research is needed to provide insights in developing better vaccines in the future. – Katarina Ruflo/Rappler.com
Katarina Ruflo is a graduate of Rappler’s fact-checking mentorship program. This fact check was reviewed by a member of Rappler’s research team and a senior editor. Learn more about Rappler’s fact-checking mentorship program here.
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