Dr. Paul Offit, a frequent critic of US Health and Human Services Secretary Robert F. Kennedy Jr., has been blocked from participating in a panel of independent experts who advise the US Food and Drug Administration on vaccines. An HHS spokesperson told CNN that Offit was among multiple advisers to FDA committees whose terms have expired, meaning they can’t participate in advisory committee work. Offit, who is director of the Vaccine Education Center at Children’s Hospital of Philadelphia, told