Effect of vaccination of humans with a live attenuated yellow fever vaccine on Treg frequency and characteristics.

Abstract

<p>At day 0, healthy adults were s.c. vaccinated with Stamaril^® or injected with a placebo. At day 1, 5, 7 and 14 post vaccination changes in Treg frequency and phenotype were determined. The delta Treg percentage per time point was determined per donor (= % Treg day_x—% Treg day₀). <b>(A)</b> Mean (± SEM) delta percentage of the frequency of rTreg (left) and aTreg (right) in the blood at the different time points after vaccination with Stamaril^® (n = 19) or placebo (n = 8). <b>(B)</b> Mean (± SEM) delta percentage of CD25 and CD31 expression on rTreg after vaccination. <b>(C)</b> Mean (± SEM) delta percentage of CD25, CD31 and HLA-DR expression on aTreg after vaccination. Means were statistically compared with an unpaired, two-tailed Mann-Whitney test (* p < 0.05 relative to placebo at the same time point).</p