Table 1 Baseline characteristics of encephalitis and meningitis cases after COVID-19 vaccination, stratified by exposure windows
Characteristic | Encephalitis | P-value | Meningitis | P-value | ||
|---|---|---|---|---|---|---|
Risk window (Days 1–28) | Control windowa (All other periods) | Risk window (Days 1–28) | Control windowa (All other periods) | |||
N (%) | N (%) | N (%) | N (%) | |||
Total | 251 (100.0) | 545 (100.0) | Â | 398 (100.0) | 964 (100.0) | Â |
Age, years (mean, SD) | 56.9 (18.0) | 56.3 (18.8) | 0.722 | 45.1 (18.8) | 44.7 (18.7) | 0.671 |
 18–29 | 33 (13.1) | 72 (13.2) | 0.342 | 109 (27.4) | 270 (28) | 0.747 |
 30–39 | 12 (4.8) | 40 (7.3) |  | 75 (18.8) | 181 (18.8) |  |
 40–49 | 30 (12.0) | 71 (13) |  | 57 (14.3) | 139 (14.4) |  |
 50–59 | 46 (18.3) | 92 (16.9) |  | 45 (11.3) | 128 (13.3) |  |
 60–69 | 67 (26.7) | 109 (20) |  | 64 (16.1) | 122 (12.7) |  |
 70–79 | 43 (17.1) | 110 (20.2) |  | 34 (8.5) | 87 (9) |  |
 80 +  | 20 (8.0) | 51 (9.4) |  | 14 (3.5) | 37 (3.8) |  |
Sex | Â | Â | 0.270 | Â | Â | 0.518 |
 Male | 145 (57.8) | 292 (53.6) |  | 200 (50.3) | 503 (52.2) |  |
 Female | 106 (42.2) | 253 (46.4) |  | 198 (49.7) | 461 (47.8) |  |
Health insurance type | Â | Â | 0.782 | Â | Â | 0.080 |
 NHI | 235 (93.6) | 513 (94.1) |  | 381 (95.7) | 940 (97.5) |  |
 Medical aid | 16 (6.4) | 32 (5.9) |  | 17 (4.3) | 24 (2.5) |  |
Region of residence | Â | Â | 0.314 | Â | Â | 0.268 |
 Metropolitan | 182 (72.5) | 376 (69) |  | 287 (72.1) | 666 (69.1) |  |
 Rural | 69 (27.5) | 169 (31) |  | 111 (27.9) | 298 (30.9) |  |
Comorbidities | ||||||
 CCI (mean, SD) | 2.0 (2.6) | 1.9 (2.3) | 0.771 | 1.3 (2.2) | 1.2 (2) | 0.345 |
  CCI < 5 | 219 (87.3) | 479 (87.9) | 0.799 | 357 (89.7) | 899 (93.3) | 0.026 |
  CCI ≥ 5 | 32 (12.7) | 66 (12.1) |  | 41 (10.3) | 65 (6.7) |  |
 Myocardial infarction | 5 (2.0) | 4 (0.7) | 0.119 | 4 (1) | 7 (0.7) | 0.601 |
 Congestive heart failure | 17 (6.8) | 36 (6.6) | 0.930 | 20 (5) | 22 (2.3) | 0.008 |
 Peripheral vascular disease | 36 (14.3) | 83 (15.2) | 0.744 | 31 (7.8) | 79 (8.2) | 0.803 |
 Cerebrovascular disease | 36 (14.3) | 64 (11.7) | 0.304 | 26 (6.5) | 58 (6) | 0.719 |
 Dementia | 22 (8.8) | 51 (9.4) | 0.788 | 19 (4.8) | 41 (4.3) | 0.670 |
 Chronic pulmonary disease | 50 (19.9) | 112 (20.6) | 0.837 | 64 (16.1) | 150 (15.6) | 0.810 |
 Rheumatic disease | 9 (3.6) | 32 (5.9) | 0.175 | 18 (4.5) | 26 (2.7) | 0.083 |
 Peptic ulcer disease | 40 (15.9) | 101 (18.5) | 0.373 | 70 (17.6) | 138 (14.3) | 0.127 |
 Hepatic disease | 63 (25.1) | 129 (23.7) | 0.661 | 73 (18.3) | 188 (19.5) | 0.621 |
 Diabetes mellitus | 57 (22.7) | 141 (25.9) | 0.338 | 59 (14.8) | 146 (15.1) | 0.880 |
 Renal disease | 8 (3.2) | 30 (5.5) | 0.154 | 9 (2.3) | 27 (2.8) | 0.572 |
 Cancer | 25 (10.0) | 35 (6.4) | 0.079 | 26 (6.5) | 43 (4.5) | 0.113 |
 HIV infection | 1 (0.4) | 0 (-) | 0.140 | 1 (0.3) | 3 (0.3) | 0.853 |