Antibody persistence and serological protection among seasonal 2007 influenza A(H1N1) infected subjects: Results from the FLUREC cohort study

Our results confirm the positive relationship between HI titer and probability of protection among naturally infected subjects, and provides evidence that protection associated with HI titer varies with age. This longitudinal analysis suggests the rise in HI titers following seasonal 2007 influenza A(H1N1) infection may persist into subsequent influenza seasons.