Claims that Pfizer has admitted its COVID-19 vaccine causes cancer have been circulating online, but the evidence does not support that conclusion.
Pfizer states that no signs of vaccine-induced cancer have been reported and that there is no evidence supporting claims that its mRNA vaccine causes cancer. The National Cancer Institute likewise reports that there is currently no evidence that COVID-19 vaccines cause cancer, cancer recurrence, or cancer progression.
That does not mean vaccine safety should never be questioned. Researchers and regulators continue to monitor possible adverse events, and genuine safety signals are investigated carefully. However, a safety signal or theoretical concern is not the same as proof that a vaccine causes cancer.
Before sharing claims about COVID-19 vaccines, it is important to distinguish between preliminary findings, scientific hypotheses, individual reports, and conclusions supported by large-scale evidence.