Table 4.

Comparison among positive responses in the 538 healthcare workers (HCWs) to anti-N IgG, anti-RBD IgG, anti-S1 IgG, and anti-S2 IgG.

Variable	Positive % (n)	Multi-comparison Cochran’s Q Test p-Value
(1) anti-N IgG	34.6 (186)	p < 0.001 * (Q)
(2) anti-RBD IgG	99.6 (536)
(3) anti-S1 IgG	99.8 (537)	1 < 2, p < 0.05 *, MRD
(4) anti-S2 IgG	86.6 (466)	1 < 3, p < 0.05 *, MRD
		1 < 4, p < 0.05 *, MRD
		4 < 2, p < 0.05 *, MRD
		4 < 3, p < 0.05 *, MRD

* = significant test; Q = Cochran’s Q test; MRD = minimum required differences method with Bonferroni p-value corrected for multiple comparisons.