I was wondering the same thing. I did read something last week that said they were still doing research to see if 2 doses were really going to be needed and would know more in a few weeks...but when Nathan got his at the end of October they said 2 doses. And I also read something about they were afraid of running out and something like they'd rather give more kids one dose than some kids no doses...which makes no sense b/c why give them any if it's not enough to do anything?