IL2 and Headache: Zika virus-infected subjects who reported headaches showed higher plasma levels of TNF-α, IL-17A, IL-2, IL-9, IL-12p70, MIP-1α, G-CSF, GM-CSF, and VEGF, and significantly higher levels of IL-5 (p = 0.0015; Figure 4B) compared to those without headache.