IL2 and infection: Proliferative responses, as well as IFN-γ, IL-2 and IL-4 ELISpot responses were not boosted after challenge in the vaccinated monkeys (Fig. S1 E–H), although it is worth noting that in the acute, post-acute and early chronic phases of infection (weeks 4, 8–22) some macaques exhibited T cell responses, in particular IL-2 and IL-4, resembling an anamnestic response to viral infection.