USA, experts undecided on the need for the third dose for those vaccinated with Moderna and Johnson & Johnson

Americans vaccinated with Pfizer are already rolling up their sleeves for the third dose, always to be done with Pfizer. Less clear at the moment is what to do for those who have had Johnson & Johnson or Moderna. The speech applies to the United States, where the Food and Drug Administration (Fda), the regulatory authority that approves drugs and vaccines, is called to decide this week on the so-called booster dose.