TABLE 5.

Multiplicative effects with 95% confidence intervals of disease severity categories and age on median salivary antibody responses to SARS-CoV-2 proteins from generalized additive models, adjusted for a spline function of interval from the onset

Parameter	Spike protein EPA_S		Nucleocapsid protein AB_N		Spike stalk subunit PS_S2i		Receptor binding domain EPA_RBD
	Multiplicative effect	P value	Multiplicative effect	P value	Multiplicative effect	P value	Multiplicative effect	P value
Severity of symptoms
Asymptomatic	Reference		Reference		Reference		Reference
Mild	3.28 (1.43–7.53)	0.005	2.79 (1.10–7.10)	0.03	3.69 (1.58–8.61)	0.003	2.35 (1.01–5.47)	0.05
Moderate	5.32 (2.31–12.3)	<0.0001	4.68 (1.83–12.0)	0.001	5.94 (2.53–13.9)	<0.0001	4.09 (1.75–9.55)	0.001
Severe	8.03 (1.86–34.7)	0.01	8.28 (1.59–43.0)	0.01	11.6 (2.59–51.5)	0.001	5.66 (1.28–25.1)	0.02
Age, per 10-yr increase	1.05 (0.92–1.19)	0.5	1.30 (1.12–1.51)	0.0004	1.12 (0.98–1.28)	0.10	1.14 (1.00–1.31)	0.05
Spline of interval from onset	NAa	0.0004	NA	0.0005	NA	<0.0001	NA	0.15

^aNA, not applicable.