Co-infection elicited reduction in the number of CD11b or CD11c myeloid cells. Six groups of BALB/c mice were intranasally treated with 32 μl of normal saline (uninfected), RSV A2 (RSV(R)), Pr/H3N2 (IAV (I)) or co-treated simultaneously (I + R) or one after the other at 24 hours interval (IR and RI). On days 2, 4 and 7 splenic cells (n = 5) were processed for flow cytometric analysis. to determine the frequency of NK1.1 gated on CD3 negative cells. (A) Proportion of CD11b myeloid cells, which was significantly low in the I + R group on day 2 was increased by day 7. (B) Proportions of CD11c myeloid cells were lower in I + R group compared to other groups on days 2 and 7. Unless indicated by lines, a vs uninfected, b vs IAV (I), c vs RSV (R), d vs IR, e vs RI. No data was available for IR and RI as well as for IAV (I), RSV(R) and I + R groups on day 2 and day 4 respectively.