FIG 2.

Mouse serum antibody titers as measured by HI. (A) Mice were immunized with inactivated purified viruses containing 3 μg of HA. On days 0, 21, 35, 49, and 63, serum anti-HA titers were measured by HI assays. (B) Same experiment as in panel A, showing the maximum titers achieved by individual mice at any time point during the course of study. Each symbol shows the titer of individual serum samples; the horizontal line indicates the group geometric mean. Statistical differences between groups are indicated by an asterisk (P < 0.05). Results from one representative experiment of 3 replicates are shown.