Martin Makary, the commissioner of the Food and Drug Administration, and Vinay Prasad, the newly appointed head of the FDA's vaccine division, have unveiled a new policy in which the government will no longer recommend Covid booster shots for healthy Americans ages 64 and younger. In addition, as of today, Covid vaccine manufacturers like Moderna and Pfizer will have to conduct trials to prove that their updated vaccines offer clinical benefits such as fewer symptoms, hospitalizations, or deaths. Previously, pharmaceutical companies only had to show that their updated booster shots produced antibodies. That less rigorous standard will still apply for people 65 and older and the immunocompromised. It is well established that people 65 and older account for the vast majority of Covid deaths, while most children, in particular, show few effects from the virus. The move is one part of what is expected to be further changes in federal Covid vaccine policy. According to The Wall Street Journal, Health and Human Services Secretary Robert F. Kennedy Jr. plans to scrap guidelines recommending routine Covid vaccinations for pregnant women, teenagers, and children. Late last month, in an interview with Phil McGraw (popularly known as Dr. Phil), Kennedy advised parents to "do your own research" before vaccinating their newborns. Less than a quarter of Americans received boosters in recent years.