Characteristics of 74 adults with JIA from the EULAR COVAX registry, stratified by vaccination status
| All (N=74) | Fully vaccinated* (N=57) | Partially vaccinated† (N=17) | ||
| Sex | Female | 54 (73) | 43 (75) | 11 (65) |
| Male | 20 (27) | 14 (25) | 6 (35) | |
| Age (median (IQR)) | 26(23, 31) | 26(23, 31) | 27(22, 32) | |
| Primary RMD diagnosis | Juvenile idiopathic arthritis, not systemic | 63 (85) | 50 (88) | 13 (76) |
| Juvenile idiopathic arthritis, systemic | 11 (15) | 7 (12) | 4 (24) | |
| RMD disease activity | Remission | 33 (45) | 23 (40) | 10 (59) |
| Minimal | 21 (28) | 17 (30) | 4 (23) | |
| Moderate | 12 (16) | 12 (21) | ||
| Severe | 1 (1) | 1 (6) | ||
| Not applicable/missing | 7 (10) | 5 (9) | 2 (12) | |
| RMD medication | None | 3 (4) | 3 (5) | |
| Abatacept | 2 (3) | 1 (2) | 1 (6) | |
| Antimalarials (including hydroxycholoroquine, chloroquine and mepacrine/quinacrine) | 2 (3) | 2 (4) | ||
| Colchicine | 1 (2) | |||
| Glucocorticoids—systemic | 6 (8) | 6 (11) | ||
| IL-1 inhibitors (including anakinra, canakinumab, rilonacept) | 2 (3) | 1 (2) | 1 (6) | |
| IL-6 inhibitors (including tocilizumab, sarilumab) | 6 (8) | 5 (9) | 1 (6) | |
| Held after vaccination | 1 (1) | 1 (2) | ||
| JAK inhibitors (including tofacitinib, baricitinib, upadacitinib) | 2 (3) | 1 (2) | 1 (6) | |
| Leflunomide | 1 (1) | 1 (2) | ||
| Methotrexate | 19 (26) | 16 (28) | 3 (18) | |
| Held after vaccination | 3 (4) | 3 (5) | ||
| Mycophenolate mofetil/mycophenolic acid | 1 (1) | 1 (2) | ||
| Held before vaccination | 1 (1) | 1 (2) | ||
| Sulfasalazine | 3 (4) | 3 (5) | ||
| TNF inhibitors (including infliximab, etanercept, adalimumab, golimumab, certolizumab and biosimilars) | 40 (54) | 30 (53) | 10 (59) | |
| Held before vaccination | 1 (1) | 1 (2) | ||
| Held after vaccination | 6 (8) | 4 (7) | 2 (12) | |
| COVID-19 vaccine type | Pfizer-BioNTech | 50 (68) | 42 (74) | 8 (47) |
| Moderna | 10 (14) | 8 (14) | 2 (12) | |
| AstraZeneca/Oxford | 10 (14) | 5 (9) | 5 (29) | |
| Janssen | 1 (1) | 1 (6) | ||
| CoronaVac | 2 (3) | 1 (2) | 1 (6) | |
| UNK | 1 (1) | 1 (2) | ||
| COVID-19 vaccine doses | 1 | 8 (11) | 8 (47) | |
| 2 | 61 (82) | 52 (91) | 9 (53) | |
| 3 | 5 (7) | 5 (9) | ||
| RMD flare | Yes | 2 (3) | 2 (4) | |
| No | 67 (91) | 51 (89) | 16 (94) | |
| Unknown | 5 (7) | 4 (7) | 1 (6) | |
| Adverse event (AE) | Yes | 46 (62) | 39 (68) | 7 (41) |
| No | 28 (38) | 18 (32) | 10 (59) | |
| Early AE types | Pain at the site of injection | 16 (22) | 11 (19) | 5 (29) |
| Redness | 2 (3) | 2 (4) | ||
| Generalised muscle pain | 9 (12) | 7 (12) | 2 (12) | |
| Generalised joint pain | 3 (4) | 3 (6) | ||
| Headache | 10 (14) | 9 (16) | 1 (6) | |
| Fever | 26 (35) | 22 (39) | 4 (23) | |
| Chills | 5 (7) | 5 (9) | ||
| Fatigue | 13 (18) | 12 (21) | 1 (6) | |
| AE of special interest | Dizziness | 1 (1) | 1 (2) | |
| AE seriousness | Non-serious | 1 (1) | 1 (2) | |
| AE outcome | Recovered/resolved without sequelae | 1 (1) | 1 (2) | |
All data are N (%) of the column unless stated otherwise. Data were reported from Belgium, France, Greece, Italy, Latvia, Portugal, Romania, Slovakia, Spain, Turkey and the UK.
*Fully vaccinated: ≥14 days after dose 2/single dose of Janssen at time of reporting.
†Partially vaccinated: ≥14 days after dose 1 to <14 days after dose 2 at time of reporting.
EULAR, European Alliance of Associations for Rheumatology; IL-1 inhibitors, interleukin-1 inhibitors; JIA, juvenile idiopathic arthritis; RMD, rheumatic and musculoskeletal disease; TNF-inhibitors, tumour necrosis factor inhibitors.;