Determination of vaccine-induced and naturally acquired class-specific mumps antibodies by two indirect enzyme-linked immunosorbent assays.

Paired sera from 46 vaccinees and 22 patients with clinically typical or atypical parotitis were tested for class-specific mumps antibodies by two different indirect enzyme-linked immunosorbent assay (ELISA) procedures. Both ELISAs appeared suitable, specific and more sensitive than neutralization (NT) and complement-fixation (CF). However, the macro-ELISA (M-ELISA) method, using beads as antigen-coated solid phase, showed a higher sensitivity than micro-ELISA (m-ELISA), performed on microplates. Diagnostic rises in mumps IgG antibodies and mumps IgA antibodies were detected more frequently by M-ELISA, mostly in post-vaccination sera. In addition, higher mean OD values of mumps IgG, IgA and IgM antibodies were generally found by M-ELISA. Nevertheless, m-ELISA appeared more convenient for evaluating class-specific mumps antibodies in large-scale studies, since the procedure is simpler, more rapid and less expensive than that of M-ELISA. Conversely, M-ELISA may be considered the test of choice for detecting low class-specific antibody levels. However, the determination of class-specific mumps antibodies appeared as an essential tool for evaluating vaccine-induced or naturally acquired mumps immunity.