Children and jabs, I have no idea, I am not a doctor or scientist, though I assume Prayut is being advised by those in the field, not by a nobody in the field like yourself.
But I do agree with mask wearing, I still use one in shops. There is absolutely no problem wearing a mask, whether kids or adults, who can breathe OK...
So, a simple yes or no is not relevant regarding jabs, if I were a doctor or scientist in the field I would probably be able to answer your question, but I am not....????