Table 2.

Frequency of SARS-CoV-2-S-reactive T cells in pre- and post-vaccination peripheral-blood specimens from nursing-home residents and healthy controls

Study group	SARS-CoV-2 S IFN-γ-producing T cells in pre/post-vaccination peripheral blood specimens
	CD8+ median % (range)/no. of specimens analysed		CD4+ median % (range)/no. of specimens analysed
	Pre-vaccination	Post-vaccination	Pre-vaccination	Post-vaccination
Nursing home residents with no documented prior SARS-CoV-2 infection	0.08 (0–3.08)/49	0.14% (0–4.98)/43	0.50 (0–3.68)/49	0 (0–3.71)/43
Nursing home residents with prior SARS-CoV-2 infection	0.38 (0–3.96)/10	0.04 (0–0.79)/9	0.73 (0–4.69)/10	0 (0–0.15)/9
Healthy controls	0 (0–1.72)/18	1.09 (0–7.33)/18	0 (0–0.69)/18	0.73 (0.03–3.08)/18

SARS-CoV-2 S, severe acute respiratory syndrome coronavirus 2 S protein; IFN, interferon.