CD40LG and measles: Male participants had 15.8 times higher adjusted odds of testing positive for measles IgM antibodies compared with female participants (aOR: 15.8; 95% CI: 2.33-107.54; <i>p</i> = 0.005).<h4>Conclusions</h4>Our results indicate a low-but not negligible-proportion of IgG measles seronegativity among participants.