Numbers of measles virus-specific (MeV-specific) or total antibody-secreting cells (ASCs) present in inguinal lymph nodes (A), PBMCs (B–D), and BM (E and F) at the indicated days after infection were measured by ELISpot assays. Plates were coated with MeV lysate (MeV-specific ASCs) or anti–monkey IgG, IgA, IgM (total ASCs) and 5 × 106 cells were added to each well. All samples were run in duplicate and data plotted as number of ASCs for individual X group macaques (A, C, D, and F) or mean ASCs ± SD per 1 × 106 PBMCs (B) or BM mononuclear cells (E) for 5 Y group macaques.