Asked for evidence of his claim, a spokesperson for Johnson sent a tweet from Aaron Siri, an attorney advising Kennedy. Siri shared a chart from the vaccine-skeptical group Informed Consent Action Network showing 17 vaccines that they allege were not licensed by the U.S. Food and Drug Administration "based on a long-term placebo-controlled trial," including vaccines for whooping cough; measles, mumps and rubella; HPV; COVID-19 and influenza.