Table 1.
Study participant characteristics.a
| Characteristic | IBD subjects | IBD subjects | P value |
|---|---|---|---|
| Third dose (n = 85)b | Two-dose series (n = 139)c | ||
| Demographics | |||
| Age, years, median (IQR) | 48 (38–60) | 41 (34–52) | .003 |
| Male, n (%) | 38 (44.7) | 71 (51) | .35 |
| Type of IBD | |||
| Crohn’s disease, n (%) | 55 (64.7) | 96 (69.1) | .44 |
| Ulcerative colitis, n (%) | 30 (35.3) | 42 (32.2) | |
| IBD unclassified | - | 1 (0.7) | |
| Vaccine data | |||
| Two-dose series | |||
| Moderna, n (%) | 37 (43.5) | 67 (48.2) | .58 |
| Pfizer, n (%) | 48 (56.5) | 72 (51.8) | |
| Third dose | |||
| Moderna, n (%) | 35 (41.2) | - | |
| Pfizer, n (%) | 50 (58.8) | - | |
| Time between completion of 2-dose series and third dose, days, median (IQR) | 149 (132–167) | - | |
| IBD treatment | |||
| Nonsystemic immunosuppression,d n (%) | 24 (28.2) | 31 (22.3) | .34 |
| Aminosalicylate or no IBD therapy, n (%) | 3 (3.5) | 17 (12.2) | |
| Vedolizumab monotherapy, n (%) | 21 (24.7) | 14 (10.1) | |
| Duration of therapy,e months, median (IQR) | 36 (17–54) | 26 (16–47) | .41 |
| Systemic immunosuppression,f n (%) | 61 (71.8) | 108 (77.7) | .34 |
| Thiopurine monotherapy, n (%) | 6 (7.1) | 14 (10.1) | |
| Anti-TNF monotherapy, n (%) | 31 (36.5) | 59 (42.4) | |
| Anti-TNF combination therapy, n (%) | 12 (14.1) | 12 (8.6) | |
| Ustekinumab monotherapy or combination therapy, n (%) | 9 (10.6) | 15 (10.8) | |
| Tofacitinib monotherapy, n (%) | 2 (2.4) | 6 (4.3) | |
| Systemic corticosteroid therapy, n (%) | 1 (1.2) | 8 (5.8) | |
| Duration of therapy, months, median (IQR) | 42 (18–117) | 43 (14–85) | .76 |
| Serum antibody concentrations | |||
| Detectable antibody concentrations, n (%) | 85 (100) | 135 (97.1) | .12 |
| Serum antibody concentrations, mg/mL, median (IQR) | 68 (32–147) | 31 (16–6.1) | <.001 |
| Time between vaccine dose and antibody measurement, days, median (IQR) | 37 (32–47) | 32 (29–34) | <.001 |
Abbreviations: IBD, inflammatory bowel disease; IQR, interquartile range; TNF, tumor necrosis factor.
Completed the 2-dose series and had serum antibody concentrations measured 28–35 days thereafter.
Completed third dose and had serum antibody concentrations measured 28–65 days thereafter.
Absence of IBD therapy, mesalamine monotherapy, or vedolizumab monotherapy.
Subjects with an absence of IBD therapy were omitted from the calculation of the duration of therapy.
Thiopurine monotherapy (ie, azathioprine, mercaptopurine), anti-TNF monotherapy, anti-TNF combination therapy (ie, plus antimetabolite), ustekinumab monotherapy or combination therapy, tofacitinib, or systemic corticosteroid therapy (ie, any of the aforementioned groups plus systemic corticosteroid).