Comparison of CMV and EBV singly infected, co-infected, and uninfected infantsCMV status had no significant effect on measles antibody titerInfection with EBV reduced measles antibody response, except when there was co-infection with CMV (median log2 hemagglutinin antibody inhibition assay titer EBV+CMV− = 3.0, EBV+CMV+ = 5.0, p = 0.003)CMV status had no significant effect on anti-meningococcus IgM or IgG. Here, CD40LG is linked to coinfection.