Immunity & infection
The goal of our study was to investigate whether demographic variables contribute to inter-individual heterogeneity in immune responses to influenza, smallpox, and measles-mumps-rubella vaccines in a diverse population of heathy children and adults.
For the influenza vaccine (50-74y/o, 62% females, 99% Caucasian), we found a negative correlation between TREC and age (p=0.001). Memory B-cell-Elispot responses were higher in females (p=0.02). Females had higher TREC levels (p=0.0003), NK-cells (p=0.005), CD8+T-cells (p=0.005), and an increased CD4+/CD8+ ratio (p=0.04).
For the smallpox vaccine (18-40y/o, 26% females, 54% Caucasian), females had higher neutralizing antibodies (159 vs 124, p<0.0001) and higher secretion of IL2 (p<0.001)/IL10 (p=0.02). Males has higher IFNγ-Elispot responses compared to females (55 vs 41 SFU, p<0.001). Caucasians had higher CD8+IFNγ-Elispot (p<0.001), IL2 (p=0.003)/IFNa (p<0.001) responses compared to African-Americans.
For the measles vaccine (11-41y/o, 27% females, 77% Caucasian), no age/sex-based differences in adaptive immunity were observed, but significantly higher neutralizing antibody (p=1.4x10^11) and IFNγ-Elispot (p=0.001) responses were found in African-Americans compared to Caucasians.
For the mumps vaccine (12-18y/o, 47% females, 93% Caucasian), females demonstrated significantly higher antibodies than males (876 vs 677 IU/mL, p=0.003). Higher levels of CD4+T-cells were found in males than in females (p=0.03).
For the rubella vaccine (11-22y/o, 45% females, 85% Caucasian), African-Americans had significantly higher rubella-specific neutralizing antibodies compared to Caucasians (p=0.0007); females had higher IL6 (p=0.03)/IFNγ (p=0.08) secretion than males.
Our data illustrate that viral vaccine-induced immune responses are significantly influenced by age, sex, and race, which highlights the importance of these variables in inter-individual variations following vaccination.