Paul Offit, a vaccine expert at Children’s Hospital of Philadelphia and one of the FDA’s commissioners, expressed concern that Pfizer’s vaccine could be underdosed. Moderna’s drug could be predicted to prevent serious disease, “but I’m not sure you can predict the same with the Pfizer vaccine.” Pfizer officials, on the other hand, emphasized that the data show that the vaccine’s effectiveness increases over time: “It’s not like there’s no effectiveness at all,” said Pfizer vice president William C. Gruber.
While the Biontech/Pfizer vaccination schedule includes three doses of 3 micrograms of mRNA each, Moderna has two doses of 25 micrograms of mRNA each.
There were no concerns on the part of the expert panel when it came to security. None of the vaccines raised serious safety concerns, side effects were mostly very mild, Moderna had a slightly higher percentage of children who developed short-term fevers than Biontech/Pfizer.
It is also unclear how widely the vaccines will be accepted. In a survey by the Kaiser Family Foundation, only 18% of parents surveyed said they would vaccinate their children immediately. 27 percent said they “definitely don’t” vaccinate their children.