Table 2

The impact of demographics, comorbidities and vaccine type on neutralising capacity and anti-RBD-IgG levels in patients with AIRD (n=308)

Variable	Neutralising capacity (%)			Anti-RBD-IgG (S/CO)
Variable	Median (IQR)	Unadjusted p value	Adjusted p value	Median (IQR)	Unadjusted p value	Adjusted p value
Demographics
Age	–	<0.001	0.058	–	<0.001	0.001
Age ≥60 years, n=147	82.4 (41.3– 95.3)	0.001	–	4.8 (0.8– 6.2)	0.006	–
Female sex, n=209	92.7 (62.5– 96.1)	0.052	0.106	5.8 (2.4– 6.7)	0.092	0.151
BMI	–	0.491	0.954	–	0.530	0.558
Comorbidities
Cardiovascular disease, n=118	87.9 (38.5– 95.2)	0.176	0.518	5.3 (0.7– 6.4)	0.321	0.841
Type 2 diabetes, n=23	82.3 (16.7– 94.7)	0.425	0.691	4.4 (0.1– 6.2)	0.435	0.834
Respiratory disease, n=41	87.8 (34.5– 95.5)	0.422	0.385	5.4 (0.7– 6.4)	0.355	0.407
Vaccination
AZD1222, n=22	53.7 (18.2– 84.5)	(ref)	(ref)	2.0 (0.3– 4.9)	(ref)	(ref)
BNT162b2, n=233	90.7 (58.9– 95.9)	0.024	0.029	5.5 (2.3– 6.5)	0.006	<0.001
mRNA-1273, n=27	95.3 (74.2– 96.8)	0.007	0.043	6.0 (3.7– 6.9)	0.003	0.001
AZD1222+mRNA, n=26	94.4 (75.2– 96.3)	0.015	0.038	6.0 (3.0– 6.8)	0.004	0.026
Vaccine interval in days	–	0.400	0.269	–	0.251	0.002
BNT162b2: vaccine interval >28 days, n=165	93.4 (69.1– 96.3)	0.265	–	5.9 (3.6– 6.8)	0.048	–
Second vaccination to testing in days	–	0.032	0.289	–	0.021	0.357

P values were estimated by a Wald test as combined p value of the two-part model. Statistically significant results in bold.
Adjusted multivariable analysis includes the covariates age, sex, BMI, type of vaccination, vaccine interval in days, interval between second vaccination and antibody testing in days, rheumatic diagnosis, comorbidity, immunosuppressive therapy, additional intake of prednisolone and pausing of any immunosuppressive therapy.
AIRD, autoimmune rheumatic diseases; BMI, body mass index; RBD, receptor-binding domain; ref, reference; S/CO, signal/cut-off.