Characterisation of the long term Zika virus-specific T-cell response

Memory T-cell responses to Zika virus (ZIKV) were assessed over a period of 8-42 months in people with monotypic ZIKV infection, or ZIKV infection with prior dengue virus (DENV) infection. INFy-ELISpot responses declined in four individuals for whom sequential samples were available. DENV cross-reactivity was identified in one individual with monotypic ZIKV infection between 8 and 22 months post onset (MPO). ZIKV-specific cross-reactivity was identified in (3 of 7) individuals with monotypic DENV 9-14 MPO. This study identified a decline in magnitude of ZIKV-specific T-cell responses over time, and demonstrated that cross-reactivity may occur many months after monotypic infection.