Naturally acquired HPV-16 antibody levels of 371 ( 95 % confidence interval [ CI ] , 242-794 ) , 204 ( 95 % CI , 129-480 ) , and 480 ( 95 % CI , 250-5756 ) EU/mL were associated with 90 % reduction of incident infection , 6-month persistent infection , and ASCUS + , respectively .