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 value | Positive NAb after two doses (n=50) | Negative NAb after two doses (n=42) | P value | |
| Demographics | ||||||
| Current age, years | 55 (42.5–64.5) | 66 (59–69) | 0.001 | 52.5 (40.5–67) | 62.5 (55.25–69) | 0.006 |
| Age >60 years | 20 (33.9) | 24 (72.7) | <0.001 | 18 (36.0) | 26 (61.9) | 0.013 |
| Female sex | 53 (89.8) | 31 (93.9) | 0.707 | 47 (94.0) | 37 (88.1) | 0.462 |
| Caucasian race | 29 (49.2) | 15 (45.5) | 0.733 | 23 (46.0) | 21 (50) | 0.702 |
| Baseline disease activity | ||||||
| CDAI | 5.0 (3.0–8.0) | 6.0 (4.0–8.0) | 0.469 | 6.0 (3.0–8.0) | 6.0 (3.0–8.0) | 0.829 |
| SDAI | 6.1 (3.1–9.1) | 7.1 (4.1–9.3) | 0.339 | 6.1 (3.2–9.4) | 7.0 (3.8–9.2) | 0.763 |
| DAS28-CRP | 2.43 (1.82–3.05) | 2.27 (2.11–2.90) | 0.843 | 2.45 (1.83–3.10) | 2.33 (1.98–2.97) | 0.742 |
| CRP | 3.3 (1.0–9.2) | 8.9 (7.3–9.8) | 0.154 | 1.6 (0.9–9.2) | 7.6 (3.8–9.8) | 0.161 |
| TJC | 1 (0–2) | 0 (0–1) | 0.086 | 1 (0–2) | 0 (0–1) | 0.259 |
| SJC | 0 (0–1) | 1 (0–1) | 0.297 | 1 (0–1) | 1 (0–1) | 0.727 |
| PGA | 3 (1–4) | 3 (2–4) | 0.491 | 3 (1–4) | 3 (1–4) | 0.570 |
| EGA | 1 (1–2) | 1 (1–2) | 0.223 | 1 (1–2) | 1 (1–2) | 0.766 |
| Current therapy | ||||||
| Prednisone | 25 (42.4) | 12 (36.4) | 0.573 | 18 (38.0) | 19 (45.2) | 0.368 |
| Prednisone dose | 5 (2.5–5) | 5 (5–5) | 0.406 | 5 (2.5–5) | 5 (5–5) | 0.278 |
| MTX-hold protocol | 29 (49.2) | 8 (24.2) | 0.019 | 23 (46.0) | 14 (33.3) | 0.217 |
| MTX monotherapy | 20 (33.9) | 5 (15.2) | 0.053 | 15 (30.0) | 10 (23.8) | 0.506 |
| Leflunomide | 8 (13.6) | 11 (33.3) | 0.024 | 7 (14.0) | 12 (28.6) | 0.086 |
| Other sDMARD | 16 (27.1) | 6 (18.2) | 0.335 | 15 (30.0) | 7 (16.7) | 0.135 |
| Abatacept | 6 (10.2) | 7 (21.2) | 0.145 | 4 (8) | 9 (21.4) | 0.066 |
| Other bDMARD | 12 (20.3) | 8 (24.2) | 0.663 | 13 (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.