Extraordinary Ministers of Holy Communion 

 
In the distribution of Communion the Priest may be assisted by other Priests who happen to be present. If such Priests are not present and there is a truly large number of communicants, the Priest may call upon extraordinary ministers to assist him, that is, duly instituted acolytes or even other faithful who have been duly deputed for this purpose.
— General Instruction of the Roman Missal, 162