Figure 5.

The effect of the timing of antibody administration on humoral immunity. Antibody dosing and immunization schedule are indicated above the graph. Mice received 0·4 mg 2F8 either during the primary immunization or during the antigen challenge. Anti-haemagglutinin (HA) titres were determined by enzyme-linked immunosorbent assay on day 21. Titres of mice treated with 2F8 on days − 1, 0 and 1 versus mice treated on days 13, 14 and 15 are shown. Mice treated with a mixture of incomplete Freund’s adjuvant (IFA) and HA are included for comparison. Results represent at least two independent experiments with three to five mice per group. **P < 0·01, *P < 0·05.