Table 3

Baseline characteristics of patients with rheumatoid arthritis who finished the study protocol with regard to IgG antibodies and NAb after two doses of the Sinovac-CoronaVac vaccine (n=92)

Positive IgG after two doses (n=59)Negative IgG after two doses (n=33)P valuePositive NAb after two doses (n=50)Negative NAb after two doses (n=42)P value
Demographics
 Current age, years55 (42.5–64.5)66 (59–69)0.00152.5 (40.5–67)62.5 (55.25–69)0.006
 Age >60 years20 (33.9)24 (72.7)<0.00118 (36.0)26 (61.9)0.013
 Female sex53 (89.8)31 (93.9)0.70747 (94.0)37 (88.1)0.462
 Caucasian race29 (49.2)15 (45.5)0.73323 (46.0)21 (50)0.702
Baseline disease activity
 CDAI5.0 (3.0–8.0)6.0 (4.0–8.0)0.4696.0 (3.0–8.0)6.0 (3.0–8.0)0.829
 SDAI6.1 (3.1–9.1)7.1 (4.1–9.3)0.3396.1 (3.2–9.4)7.0 (3.8–9.2)0.763
 DAS28-CRP2.43 (1.82–3.05)2.27 (2.11–2.90)0.8432.45 (1.83–3.10)2.33 (1.98–2.97)0.742
 CRP3.3 (1.0–9.2)8.9 (7.3–9.8)0.1541.6 (0.9–9.2)7.6 (3.8–9.8)0.161
 TJC1 (0–2)0 (0–1)0.0861 (0–2)0 (0–1)0.259
 SJC0 (0–1)1 (0–1)0.2971 (0–1)1 (0–1)0.727
 PGA3 (1–4)3 (2–4)0.4913 (1–4)3 (1–4)0.570
 EGA1 (1–2)1 (1–2)0.2231 (1–2)1 (1–2)0.766
Current therapy
 Prednisone25 (42.4)12 (36.4)0.57318 (38.0)19 (45.2)0.368
 Prednisone dose5 (2.5–5)5 (5–5)0.4065 (2.5–5)5 (5–5)0.278
 MTX-hold protocol29 (49.2)8 (24.2)0.01923 (46.0)14 (33.3)0.217
 MTX monotherapy20 (33.9)5 (15.2)0.05315 (30.0)10 (23.8)0.506
 Leflunomide8 (13.6)11 (33.3)0.0247 (14.0)12 (28.6)0.086
 Other sDMARD16 (27.1)6 (18.2)0.33515 (30.0)7 (16.7)0.135
 Abatacept6 (10.2)7 (21.2)0.1454 (8)9 (21.4)0.066
 Other bDMARD12 (20.3)8 (24.2)0.66313 (26.0)7 (16.7)0.280
  • Results are expressed in median (IQR) and n (%).

  • Continuous data were compared using Mann-Whitney U test and categorical variables with χ2 or Fisher’s exact test, as appropriate, as two-sided analyses.

  • Flare was defined as CDAI >10.

  • bDMARD, biologic disease-modifying antirheumatic drugs (tumour necrosis factor inhibitors and tocilizumab); CDAI, Clinical Disease Activity Index; CRP, C reactive protein; DAS28-CRP, Disease Activity Score with 28 joints and C reactive protein; EGA, evaluator global disease assessment; MTX, methotrexate; NAb, neutralising antibody; PGA, patient global disease assessment; SDAI, Simplified Disease Activity Index; sDMARD, synthetic disease-modifying antirheumatic drugs (sulfasalazine, hydroxychloroquine, tofacitinib); SJC, swollen joint count; TJC, total joint count.