FluoroSpot responses to recombinant subunit glycoprotein E zoster vaccine (A) and live attenuated zoster vaccine (B) by age and treatment group. Data were derived from 158 participants. Bars represent geometric mean spot-forming cells per 10⁶ peripheral blood mononuclear cells and 95% confidence interval at the time points indicated at the bottom of each graph. Analytes and stimulants are indicated in the title of each graph. Abbreviations: HZ/su, recombinant subunit glycoprotein E zoster vaccine; gE, glycoprotein E; IFN-γ, interferon gamma; IL-2, interleukin 2; PBMCs, peripheral blood mononuclear cells; SFC, spot-forming cell; VZV, varicella zoster virus; ZV, live attenuated zoster vaccine.