CD4 and infection: Together, the results presented in Fig. 3 and Supplementary Fig. 3 suggest that (a) both control and pregnant mice respond to challenge infection with a substantial increase in differentiation, proliferation and functional activation of CD4+T and CD8+T subpopulations, (b) pre-immunization with nano2/4 elicited significantly higher level of expansion and functional activation of CD4+Tem and CD4+Tcm subsets in infected pregnant (but not non-pregnant) mice, and (c) increase in functional activation of CD8+Tcm subsets was primarily noted in vaccinated/infected pregnant mice.