Per-protocol VE was 16.1 % ( 95 % CI : -1.1 % , 30.4 % ; one-sided p = 0.032 ) against clinically confirmed AOM , 67.1 % ( 95 % CI : 17.0 % , 86.9 % ) against vaccine serotype clinically confirmed AOM , 100 % ( 95 % CI : 74.3 % , 100 % ) against vaccine serotype IPD , and 65.0 % ( 95 % CI : 11.1 % , 86.2 % ) against any IPD .