Fig. 1.

Anti-MV antibody levels and seroconversion rates. Serum levels of anti-MV antibodies were measured prior to or after injection of MV1-F4, Rouvax or saline. Antibody levels were expressed as the ratio between the optical density (OD) at 490 and at 620 nm. Animals were considered to be responders if the absorbance exceeded the cut-off value, for a serum dilution of 1:500. Each line represents one monkey. Plain and open symbols represent male and female monkeys, respectively. a Young animals (N = 6/group) were immunized at day 1 and sacrificed at day 11 (groups 1, 2 and 3). Blood samples were taken at days 0 and 11. b Young animals (N = 6/group) were immunized at days 1, 29 and 57, and sacrificed at day 85 (groups 4, 5 and 6). Blood samples were taken at days 0, 11, 29, 56, 67 and 85. c Sexually mature animals (N = 3/group) were immunized at days 1, 29 and 57 (groups 7 and 8). Blood samples were taken at days 0, 11, 29, 56, 67 and 85