MRC1L-B expression on monocytes. Chickens were uninfected, or experimentally infected with ER on day 0, “naïve” and “vaccinated” groups. Blood samples were collected at the indicated days. In A expression is shown as median fluorescence intensity (MFI) in the monocyte gate as defined in Additional file 2, and results are shown as group mean values ± 95% CI where non-overlapping CI indicate statistically significant differences. On days –3 and 15 n = 13/group, on days 1, 5 and 8 n = 7/group and on days 3 and 11 n = 6/group. In B–D MRC1L-B expression on monocytes on B day 1, C day 3 and D day 5 after ER infection is shown as fluorescence intensity for one representative uninfected, “naïve” and “vaccinated” chicken, respectively. Histograms were compiled using the FlowJo™ software package. For details see “Materials and methods” section.