Demographic and clinical characteristics of patients with post-vaccination flare
| IJD n=206 | CTD n=38 | Vasculitis n=22 | OIRMD n=6 | All patients n=272 | |
| Age, years, mean (SD) | 56.2 (13.4) | 50.8 (13.1) | 66.6 (18.9) | 53.7 (17.7) | 56.2 (14.3) |
| Sex | |||||
| Female | 156 (75.7) | 32 (84.2) | 14 (63.6) | 2 (33.3) | 204 (75) |
| Male | 50 (24.3) | 6 (15.8) | 8 (36.4) | 4 (66.7) | 68 (25) |
| Disease activity | |||||
| Remission | 69 (33.5) | 15 (39.5) | 13 (59.1) | 1 (16.7) | 98 (36) |
| Low disease activity | 86 (41.7) | 10 (26.3) | 5 (22.7) | 2 (33.3) | 103 (37.9) |
| Moderate disease activity | 36 (17.5) | 8 (21.1) | 4 (18.2) | 3 (50) | 51 (18.8) |
| High disease activity | 4 (1.9) | 0 | 0 | 0 | 4 (1.5) |
| Missing/unknown | 11 (5.4) | 5 (13.1) | 0 | 0 | 16 (5.9) |
| Vaccine dose before flare | |||||
| First | 80 (38.8) | 13 (34.2) | 8 (36.4) | 4 (66.7) | 105 (38.6) |
| Second | 73 (35.4) | 15 (39.5) | 9 (40.9) | 1 (16.7) | 98 (36) |
| Unknown/missing | 53 (25.7) | 10 (26.3) | 5 (22.7) | 1 (16.7) | 69 (25) |
| Vaccine type before flare | |||||
| Pfizer | 140 (68) | 29 (76.3) | 18 (81.8) | 4 (66.7) | 191 (70.2) |
| Moderna | 20 (9.7) | 3 (7.9) | 0 | 1 (16.7) | 24 (8.8) |
| AstraZeneca | 43 (20.9) | 6 (15.8) | 4 (18.2) | 0 | 53 (19.5) |
| CoronaVac/Sinovac | 0 | 0 | 0 | 1 (16.7) | 1 (0.4) |
| Unknown/missing | 3 (1.5) | 0 | 0 | 0 | 3 (1.1) |
| Time between vaccine and flare, days, mean (SD) | 6.8 (7.9) (n=141) | 7.8 (7.5) (n=27) | 11.1 (11.4) (n=16) | 1 (1) (n=3) | 7.2 (8.2) (n=187) |
| Type of flare | |||||
| Fever | 15 (7.3) | 4 (10.5) | 2 (9.1) | 1 (16.7) | 22 (8.1) |
| Weight loss | 0 | 0 | 0 | 1 (16.7) | 1 (0.4) |
| Increase in fatigue | 16 (7.8) | 10 (26.3) | 4 (18.2) | 3 (50) | 33 (12.1) |
| Increase in dryness | 0 | 3 (7.9) | 0 | 1 (16.7) | 4 (1.5) |
| Enlarged lymph nodes | 2 (1) | 3 (7.9) | 0 | 0 | 5 (1.8) |
| Polyarthralgia | 77 (37.4) | 14 (36.8) | 9 (40.9) | 3 (50) | 103 (37.9) |
| Arthritis flare | 118 (57.3) | 9 (23.7) | 7 (31.8) | 1 (16.7) | 135 (49.6) |
| Cutaneous flare | 9 (4.4) | 6 (15.8) | 2 (9.1) | 3 (50) | 20 (7.4) |
| Pulmonary flare | 1 (0.5) | 1 (2.6) | 2 (9.1) | 0 | 4 (1.5) |
| Renal flare | 0 | 0 | 2 (9.1) | 0 | 2 (0.7) |
| Neurological flare | 0 | 2 (5.3) | 1 (4.5) | 0 | 3 (1.1) |
| Muscular flare | 6 (2.9) | 4 (10.5) | 3 (13.6) | 1 (16.7) | 14 (5.1) |
| Cardiac flare | 1 (0.5) | 1 (2.6) | 1 (4.5) | 0 | 3 (1.1) |
| Gastrointestinal flare | 1 (0.5) | 0 | 0 | 0 | 1 (0.4) |
| Haematological flare | 0 | 3 (7.9) | 0 | 0 | 3 (1.1) |
| Other | 16 (7.8) | 3 (7.9) | 1 (4.5) | 2 (33.3) | 22 (8.1) |
| Severity of flare | |||||
| Mild | 69 (33.5) | 17 (44.7) | 6 (27.3) | 1 (16.7) | 93 (34.2) |
| Moderate | 101 (49) | 12 (31.6) | 10 (45.5) | 1 (16.7) | 124 (45.6) |
| Severe without hospitalisation | 19 (9.2) | 2 (5.3) | 3 (13.6) | 1 (16.7) | 25 (9.2) |
| Severe with hospitalisation | 2 (1) | 4 (10.5) | 3 (13.6) | 3 (50) | 12 (4.4) |
| Unknown | 8 (3.9) | 2 (5.3) | 0 | 0 | 10 (3.7) |
| New medication or dosage increase due to flare | |||||
| Yes | 86 (41.7) | 19 (50) | 13 (59.1) | 3 (50) | 121 (44.5) |
| No | 110 (53.4) | 15 (39.5) | 8 (36.4) | 3 (50) | 136 (50) |
| Unknown | 10 (4.9) | 4 (10.5) | 1 (4.5) | 0 | 15 (5.5) |
CTD, connective tissue disease; IJD, inflammatory joint disease; OIRMD, other inflammatory rheumatic and musculoskeletal disease.