Changes in
gelatin particle agglutination (PA), hemagglutination inhibition (HI), and neutralization (NT)
antibodies were compared using sera from 124 individuals collected between 3 weeks and 10 years after
measles vaccination, and the relationship between these changes and
IgG avidity was studied. PA, HI, and NT
antibodies peaked 4-5 months after vaccination. The rate of increase in mean antibody titer from 0-1 months after vaccination to peak levels was 1.7-fold for NT, 1.5-fold for HI, and 7.4-fold for PA
antibodies. Peak mean antibody titer was 2(11.8) for PA, 2(6.7) for NT and 2(6.7) for HI
antibodies. After peaking PA
antibodies changed in parallel with NT and HI antibody titers, and correlated strongly with both
antibodies (r = 0.801 and 0.840). In contrast, NT and HI
antibodies were consistent throughout the period.
IgG avidity increased for 4-5 months following vaccination, peaking at 45%, and remaining constant at 40-50% for the next 10 years. PA antibody is strongly influenced by
IgG avidity, unlike NT and HI
antibodies. Due to the effects of
IgG avidity, PA
antibodies increase more significantly than NT and HI
antibodies as
IgG antibodies mature following vaccination, resulting in a weak correlation between PA and NT or HI
antibodies. Following the increase in
IgG avidity to maturation, PA
antibodies correlated strongly with NT and HI
antibodies. PA assay detected
IgM antibodies against measles virus more efficiently than the NT test. The PA assay thus differs from conventional, commonly used NT and HI assays. PA assay is simple and rapid, making it very useful for detecting
measles antibodies provided that its unique features are taken into accounts.