Associations Between Demographic Variables and Multiple Measles-Specific Innate and Cell-Mediated Immune Responses After Measles Vaccination

Measles remains a public health concern due to a lack of vaccine use and vaccine failure. A better understanding of the factors that influence variations in immune responses, including innate/inflammatory and adaptive cellular immune responses, following measles-mumps-rubella (MMR) vaccination could increase our knowledge of measles vaccine-induced immunity and potentially lead to better vaccines. Measles-specific innate/ inflammatory and adaptive cell-mediated immune (CMI) responses were characterized using enzyme-linked immunosorbent assays to quantify the levels of secreted IL-2, IL-6, IL-10, IFN-alpha, IFN-gamma, IFN-lambda 1, and TNF-alpha in PBMC cultures following in vitro stimulation with measles virus (MV) in a cohort of 764 school-aged children. IFN-gamma ELISPOT assays were performed to ascertain the number of measles-specific IFN-gamma-secreting cells. Cytokine responses were then tested for associations with self-declared demographic data, including gender, race, and ethnicity. Females secreted significantly more TNF-alpha, IL-6, and IFN-alpha (p<0.001, p<0.002, p<0.04, respectively) compared to males. Caucasians secreted significantly more IFN-a, IL-10, IL-2, TNF-a, IL-6, and IFN-a (p<0.001, p<0.001, p<0.001, p<0.003, p<0.01, and p<0.02, respectively) compared to the other racial groups combined. Additionally, Caucasians had a greater number of IFN-gamma-secreting cells compared to other racial groups (p< 0.001). Ethnicity was not significantly correlated with variations in measles-specific CMI measures. Our data suggest that innate/inflammatory and CMI cytokine responses to measles vaccine vary significantly by gender and race. These data further advance our understanding regarding inter-individual and subgroup variations in immune responses to measles vaccination.