While peripheral CD4+, CD8+, and γδ T‐cell populations and their respective naïve/memory/effector subpopulations showed comparable frequencies between carriers and noncarriers, carriers exhibited significantly lower frequencies of IFN‐γ‐producing CD4+ and CD8+ T lymphocytes during early infection, indicating compromised cell‐mediated immune responses essential for viral clearance. The gene discussed is CD4; the disease is infection.