Tara Parker-Pope and former Senator (R-TN) Dr. Bill Frist, a physician, have called his criticism of the H1N1 flu vaccinations unscientific. Infectious diseases expert Paul Offit has written that misinformation about vaccines from celebrities like Maher has put children at unnecessary risk. Offit says that celebrities like Maher are seen as "less credible" and would still be considered just "great entertainment" if they weren't joined by the former Director of the National Institutes of Health, Dr. Bernadine Healy and influential pediatrician, Dr. Robert Sears.