Table 4

SARS-CoV-2 IgG titre decay rates in IMID versus controls

	Days for SARS-CoV-2 Ab titre to reach 7.0 U/mL	Days for SARS-CoV-2 Ab titre to reach 0 U/mL	Change after 90 days (%)	Slope coefficient
	Days for SARS-CoV-2 Ab titre to reach 7.0 U/mL	Days for SARS-CoV-2 Ab titre to reach 0 U/mL	Change after 90 days (%)	95% CI	P value
AZ vaccine
csDMARD IgG titre=1.05–0.0034 (days after second vaccination) R∧2=2.8%	68.3	308.8	50.53	−0.010 to 0.003	0.313
bDMARD IgG titre=1.29–0.0062 (days after second vaccination) R∧2=9.0%	71.8	208.1	72.31	−0.012 to −0.00006	0.048
tsDMARD IgG titre=1.37–0.0082(days after second vaccination) R∧2=17.3%	64.0	167.1	81.70	−0.013 to −0.003	0.001
Pfizer vaccine
csDMARD IgG titre=1.55–0.0038(days after second vaccination) R∧2=9.2%	185.5	407.9	54.51	−0.0078 to 0.0001	0.061
bDMARD IgG titre=1.56–0.0052(days after second vaccination) R∧2=20.7%	137.5	300.0	65.96	−0.0078 to −0.0026	0.000
tsDMARD IgG titre=1.97–0.0097(days after second vaccination) R∧2=46.3%	116.0	203.1	86.61	−0.013 to −0.007	0.000
AZ vaccine control
IgG titre=1.51–0.0107(days after second vaccination) R∧2=30.9%	62.1	141.1	89.12	−0.0152 to −0.006	0.000
Pfizer vaccine control
IgG titre=1.60–0.0036(days after second vaccination) R∧2=13.2%	209.7	444.4	52.57	−0.006 to −0.0007	0.013

Bold values are significant with p-value <0.05.
DMARD, disease-modifying antirheumatic therapy; IMID, immune-mediated inflammatory diseases; tsDMARD, targeted synthetic DMARD.