Table 4.

Patients characteristics in different serology-based groups

	negative serology	low titer	high titer	Pv
	(n = 20)	(n = 16)	(n = 18)
Age (years)	73.21 (66.13–77.98)	65.28 (54.71–75.45)	66.00 (48.74–76.51)	0.220
Male	13 (65%)	9 (56.3%)	10 (55.6%)	0.804
Lymphoma	16 (80%)	7 (43.8%)	10 (55.6%)	0.084
Myeloma	4 (20%)	8 (50%)	8 (44.4%)
CLL	0 (0%)	1 (6.3%)	0 (0%)
VAHL on PET-CT	2 (10%)	5 (31.3%)	13 (72.2%)	<0.001 b,c
VAHL on PET-CT after Vac-1	1/4 (25%)	1/6 (16.7%)	3/6 (50%)	0.358
VAHL on PET-CT after Vac-2	1/16 (6.3%)	4/10 (40%)	10/12 (83.3%)	<0.001 a,b,c

Categorical variables are reported as frequency and percentage; Continuous variables are reported as median and IQR. Vac-1, first vaccine dose; Vac-2, booster vaccine dose

^a: a statistically significant difference found between negative serology and low titer groups

^b: a statistically significant difference found between negative serology and high titer groups

^c: a statistically significant difference found between low titer and high titer groups