Ladapo, who rose to national prominence during the pandemic for spreading misinformation about the virus and promoting vaccination hesitancy, is asking the Food and Drug Administration (FDA) and the U.S. Centers for Disease Control and Prevention (CDC) to answer questions about his concerns regarding DNA integration in mRNA vaccines.
In a December 6 letter, Ladapo said he believed the drug delivery system used by mRNA vaccines could be an "efficient vehicle for delivering contaminant DNA into human cells." He said that because DNA integration could theoretically affect oncogenes—the genes that have the ability to "transform a healthy cell into a cancerous cell"—that DNA contaminant could cause cancer in vaccine recipients.