Table 3. Multivariable linear regression analysis for IgG antibody against the SARS-CoV-2 spike protein titers and neutralizing activity.

	IgG antibody				Neutralizing activity
	β	SE	Adjusted β	p value	β	SE	Adjusted β	p value
Age	−12.6	3.3	−0.241	<0.001	−3.2	0.8	−0.244	<0.001
Female sex	42.8	95.0	0.027	0.65	55.8	24.5	0.142	0.024
First dose
Local pain, swelling, and redness	−253.8	110.3	−0.175	0.022	−23.5	28.4	−0.065	0.41
Fever over 37.5°C	−170.5	259.4	−0.042	0.51	37.8	66.8	0.037	0.57
Muscle pain, joint pain	42.3	127.9	0.023	0.74	−3.1	32.9	−0.007	0.93
Fatigue	29.4	117.9	0.018	0.80	−7.2	30.3	−0.017	0.81
Headache	−77.7	146.9	−0.036	0.60	−43.8	37.8	−0.080	0.25
Second dose
Local pain, swelling, and redness	57.7	110.2	0.040	0.60	4.2	28.4	0.012	0.88
Fever over 37.5°C	473.7	112.3	0.294	<0.001	49.4	28.9	0.122	0.089
Muscle pain, joint pain	223.8	108.9	0.154	0.041	69.3	28.0	0.190	0.014
Fatigue	−7.6	101.5	−0.005	0.94	15.1	26.1	0.043	0.56
Headache	44.3	102.1	0.031	0.67	5.7	26.3	0.016	0.83
Daily medication
Immunosuppressive drug	−1352.4	451.6	−0.179	0.003	−440.8	116.2	−0.233	<0.001
Antiallergic drug	−38.4	248.4	−0.009	0.88	−17.1	64.0	−0.017	0.79
Analgesic and antipyretic drug	−400.9	184.8	−0.137	0.031	−134.2	47.6	−0.183	0.005
Drug for harmful aftereffects	−64.7	112.6	−0.039	0.57	−22.6	29.0	−0.054	0.44

β, coefficient; SE, standard error