CD4 and tuberculosis: In auto-HSCT recipients, CD4 T-cell responses displayed polyfunctional profiles similar to those in adults ≥50 YOA,39 and polyfunctional responses after vaccines against tuberculosis, malaria, melanoma, or HIV have been shown to correlate with protection.45–48 While data for RZV-elicited CD8 T-cell responses are not available for IC populations,8,10,13–15 using the same CMI assessment methods, only scarce CD8 T-cell responses were detected in older adults, which did not increase upon vaccination with RZV.40,42