Table 1. Baseline Characteristics of the Participants Who Received at Least 1 Dose of the Assigned Treatment.
| Characteristic | No. (%) | |||
|---|---|---|---|---|
| Cohort 1 | Cohort 2 | |||
| Vaccine (n = 14 375) | Placebo (n = 3597) | Vaccine (n = 4790) | Placebo (n = 1197) | |
| Age, y | ||||
| Mean (SD) | 39.4 (11.9) | 39.1 (11.7) | 39.6 (12.1) | 39.9 (11.7) |
| ≤65 | 14 031 (97.6) | 3511 (97.6) | 4676 (97.6) | 1169 (97.7) |
| Sex | ||||
| Men | 8637 (60.1) | 2127 (59.1) | 2866 (59.8) | 717 (59.9) |
| Women | 5738 (39.9) | 1470 (40.9) | 1924 (40.2) | 480 (40.1) |
| Educational level | ||||
| Illiterate | 196 (1.4) | 42 (1.2) | 73 (1.5) | 17 (1.4) |
| High school | 1370 (9.5) | 355 (9.9) | 556 (11.6) | 139 (11.6) |
| Diploma or postdiploma | 4942 (34.4) | 1240 (34.5) | 1471 (30.7) | 356 (29.7) |
| Bachelor’s degree | 4825 (33.6) | 1225 (34.1) | 1644 (34.3) | 412 (34.4) |
| ≥Master’s degree | 3042 (21.2) | 735 (20.4) | 1046 (21.8) | 273 (22.8) |
| Underlying diseasesa | ||||
| Yes | 4253 (29.6) | 973 (27.1) | 1446 (30.2) | 352 (29.4) |
| BMI | ||||
| Mean (SD) | 26.6 (4.6) | 26.5 (4.6) | 27.2 (4.5) | 27.3 (4.6) |
| <25 | 5410 (37.6) | 1407 (39.1) | 1540 (32.2) | 373 (31.2) |
| 25-30 | 5887 (41.0) | 1457 (40.5) | 2113 (44.1) | 533 (44.5) |
| >30 | 3078 (21.4) | 733 (20.4) | 1137 (23.7) | 291 (24.3) |
| Anti–SARS-CoV-2 S1 IgG on day 0b | ||||
| Positive | 1684 (35.7) | 436 (36.7) | 538 (33.7) | 113 (29.7) |
| Negative | 3034 (64.3) | 751 (63.3) | 1057 (66.3) | 267 (70.3) |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); IgG, immunoglobulin G.
a
Underlying diseases: obesity (BMI >30), controlled hypertension, chronic kidney disease, chronic liver disease, type 2 diabetes, chronic obstructive pulmonary disease), controlled asthma, history of any malignancy or cancer, and ischemic heart disease. The details are provided in the protocol (Supplement 1).
b
IgG antibodies against the S1 subunit (S1 IgG).