A total of @ children were randomly assigned at a ratio of @:@:@ to receive @ injections @ days apart of A/California/@ / @ ( H@N@ ) - AS@ vaccine at dose @ and saline placebo at dose @ , @ doses @ days apart of A/California/@ / @ ( H@N@ ) - AS@ vaccine ( the Ad@ group ) , or @ doses @ days apart of nonadjuvanted A/California/@ / @ ( H@N@ ) vaccine ( the NAd@ group ) .