WHY DO YOU USE HALF DOSE OF MODERNA? On 25 October, the EMA decided to also recommend Moderna for the third dose, specifying to use half the dosage, so 50 micrograms in 0.25 liters instead of 100. In those same days (20 October), Moderna had also received the authorization to use the vaccine as a third dose in the United States, where the American FDA has also indicated half a dosage