Table. Demographic and Clinical Characteristics of Study Participants, Stratified by Immune Response to the First Dose of SARS-CoV-2 Messenger RNA Vaccine, and Associations With Developing an Antibody Response (N = 436).
| Antibody, No. (%) | Bivariable IRR (95% CI) | P value | Adjusted multivariable IRR (95% CI)a | P value | ||
|---|---|---|---|---|---|---|
| Detectable (n = 76) | Undetectable (n = 360) | |||||
| Age group, y | ||||||
| 18-39 | 30 (39) | 69 (19) | 0.81 (0.71-0.93)b | .003 | 0.83 (0.73-0.93) | .002 |
| 40-59 | 18 (24) | 132 (37) | ||||
| ≥60 | 28 (37) | 159 (44) | ||||
| Sexc | ||||||
| Female | 48 (64) | 212 (59) | 1.12 (0.73-1.73)d | .60 | ||
| Male | 27 (36) | 138 (41) | ||||
| Racec,e | ||||||
| Non-Whitef | 8 (11) | 38 (11) | 0.99 (0.51-1.94)g | .99 | ||
| White | 67 (89) | 312 (89) | ||||
| Type of organ transplanth | ||||||
| Kidney | 31 (41) | 188 (53) | 0.68 (0.45-1.04)i | .07 | ||
| Liver | 28 (37) | 50 (14) | ||||
| Heart | 9 (12) | 57 (16) | ||||
| Lung | 4 (5) | 45 (13) | ||||
| Pancreas | 1 (1) | 4 (1) | ||||
| Other (multiorgan) | 2 (3) | 12 (3) | ||||
| Time since transplant, yj | ||||||
| <3 | 13 (17) | 106 (30) | 1.88 (1.21-2.93)k | .005 | 1.45 (0.96-2.20) | .08 |
| 3-6 | 12 (16) | 77 (22) | ||||
| 7-11 | 19 (25) | 82 (23) | ||||
| ≥12 | 31 (41) | 89 (25) | ||||
| Type of regimen | ||||||
| Includes anti–metabolite maintenance immunosuppressionl | 28 (37) | 292 (81) | 0.21 (0.14-0.32)m | <.001 | 0.22 (0.15-0.34) | <.001 |
| Does not include anti–metabolite maintenance immunosuppression | 48 (63) | 68 (19) | ||||
| Vaccinen | ||||||
| mRNA-1273 (Moderna) | 52 (69) | 152 (43) | 2.14 (1.24-3.69)o | .006 | 2.15 (1.29-3.57) | .003 |
| BNT162b2 (Pfizer-BioNTech) | 23 (31) | 200 (57) | ||||
| Enzyme immunoassay manufacturerp | ||||||
| Roche Elecsys | 64 (84) | 266 (74) | 1.71 (0.96-3.05)q | .07 | ||
| EUROIMMUN | 12 (16) | 94 (26) | ||||
Abbreviation: IRR, incidence rate ratio.
Model adjusted for age, years since transplant, antimetabolite maintenance immunosuppression, days since vaccination, and vaccine type.
Per 10-year increase in age.
Missing data for 11 participants (1 in detectable category and 10 in undetectable category).
Comparison of female vs male.
The options were defined by the investigators and classified by the participants. Race/ethnicity was assessed to evaluate potential race/ethnicity differences in immune response.
Includes Black or African American, Asian, American Indian or Alaska Native, Native Hawaiian or other Pacific Islander, Arab or Middle Eastern, and multiracial.
Comparison of non-White vs White.
Missing data for 5 participants (1 in detectable category and 4 in undetectable category).
Comparison of kidney transplant recipient vs non–kidney transplant recipient.
Missing data for 7 participants (1 in detectable category and 6 in undetectable category).
Comparison of 6 or more years since transplant vs less than 6 years since transplant. This was used as a cutoff since it was the median time since transplant.
Includes mycophenolate mofetil, mycophenolic acid, or azathioprine.
Comparison of other maintenance immunosuppression vs anti–metabolite maintenance immunosuppression.
Missing data for 9 participants (1 in detectable category and 8 in undetectable category).
Comparison of mRNA-1273 vs BNT162b2. Also adjusted for number of days between vaccination and antibody testing (median of 21 days for mRNA-1273 and 20 days for BNT162b2).
The antibody-positive cutoffs (determined by the manufacturer) were 0.80 U/mL or greater for Roche Elecsys and 1.1 or greater arbitrary units for EUROIMMUN.
Comparison of Roche Elecsys vs EUROIMMUN.