Fig 5.

Cross-reactivity of postvaccination human serum antibodies elicited by the B/Brisbane/60/2008 vaccine against various B/Victoria lineage viruses analyzed by HI test. GMTs of HI tests to egg-grown (black bars) and MDCK-grown (white bars) viruses are shown. The broken line indicates an HI GMT of 40. Numbers above the columns indicate percentages compared with the GMTs of the vaccine virus. Human serum samples were collected in 2009 from an adult group (n = 24; age range, 21 to 40 years; mean, 28.4 years) (A), a middle-aged group (n = 21; age range, 42 to 60 years; mean, 51.4 years) (B), and an elderly group (n = 24; age range, 69 to 103 years; mean, 87.3 years) (C).