Quantification of a cell-mediated immune response against varicella zoster virus by assessing responder CD4 high memory cell proliferation in activated whole blood cultures.

•VZV responder CD4high memory cell proliferation was detected in whole blood culture.•These cells were mainly effector memory cells and had a cytotoxic attribute.•The proliferation of these cells was specific to people with history of varicella.•This proliferation was low in the elderly and increased after live VZV vaccine.•Quantifying responder CD4high memory cell proliferation to measure VZV-CMI is novel.