Healthy children aged @-@ months were randomised ( @:@:@ ratio , by computer-generated randomisation list , with block size seven ) to receive @ days apart ( @ ) two doses of MMRV ( MMRV group ) , or ( @ ) MMR at dose one and monovalent varicella vaccine at dose two ( MMR+V group ) , or ( @ ) two doses of MMR ( MMR group ; control ) .