Table 2.
Demographic characteristics of the cohort participants by epidemic wave
| Variable | Overall | B.1.1.33 | Zeta | Gamma | Delta | Omicron |
| Median (IQR) | Median (IQR) | Median (IQR) | Median (IQR) | Median (IQR) | Median (IQR) | |
| Days of follow-up | 222 (105–365) | 317 (196–522) | 265 (147–426) | 162 (68–256) | 137 (49–197) | 27 (14–93) |
| Age (years) | 16 (7–35) | 14 (5–36) | 19 (7–35) | 19 (8–38) | 15 (8–32) | 8 (4-24) |
| N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
| Sex | ||||||
| Male | 665/1760 (38) | 239/623 (38) | 131/343 (38) | 174/464 (37) | 106/287 (37) | 15/43 (35) |
| Female | 1095/1760 (62) | 384/623 (62) | 212/343 (62) | 290/464 (63) | 181/287 (63) | 28/43 (65) |
| Age groups | ||||||
| 0–12 | 758/1760 (43) | 289/623 (46) | 138/343 (40) | 173/464 (37) | 129/287 (45) | 29/43 (67) |
| 13–17 | 153/1760 (9) | 46/623 (8) | 28/343 (8) | 51/464 (11) | 28/287 (10) | 0 |
| >=18 | 849/1760 (48) | 288/623 (46) | 177/343 (52) | 240/464 (52) | 130/287 (45) | 14/43 (33) |
| Race* | ||||||
| White | 250/849 (29) | 81/288 (28) | 57/177 (32) | 71/240 (30) | 36/130 (28) | 5/14 (36) |
| Non-white | 571/849 (67) | 204/288 (71) | 113/177 (64) | 154/240 (64) | 91/130 (70) | 9/14 (64) |
| Missing | 28/849 (4) | 3/288 (1) | 7/177 (4) | 15/240 (6) | 3/130 (2) | 0 |
| Completed primary school* | ||||||
| Yes | 651/849 (77) | 219/288 (76) | 138/177 (78) | 179/240 (75) | 105/130 (81) | 10/14 (71) |
| No | 159/849 (19) | 65/288 (23) | 28/177 (16) | 43/240 (18) | 19/130 (15) | 4/14 (29) |
| Missing | 39/849 (4) | 4/288 (1) | 11/177 (6) | 18/240 (7) | 6/130 (4) | 0 |
| Smoking* | ||||||
| Yes | 73/849 (9) | 28/288 (9) | 10/177 (6) | 11/240 (5) | 16/130 (13) | 8/14 (57) |
| No | 752/849 (89) | 258/288 (90) | 160/177 (90) | 217/240 (90) | 111/130 (85) | 6/14 (43) |
| Missing | 24/849 (2) | 3/288 (1) | 7/177 (4) | 11/240 (5) | 3/130 (2) | 0 |
*Race, schooling and smoking were only collected for adults.