Table 1 Characteristics of study population of COVID-19 index cases and close contacts in California prisons
From: Infectiousness of SARS-CoV-2 breakthrough infections and reinfections during the Omicron wave
Index cases (n = 1,226) (n (%) or mean (s.d.)) | Close contacts* (n = 1,226) (n (%) or mean (s.d.)) | |||
|---|---|---|---|---|
No COVID-19 vaccination (n = 273) | Any COVID-19 vaccination (n = 953) | No COVID-19 vaccination (n = 173) | Any COVID-19 vaccination (n = 1,053) | |
Sex | ||||
Female | 8 (3%) | 30 (3%) | 7 (4%) | 31 (3%) |
Male | 265 (97%) | 923 (97%) | 166 (96%) | 1,022 (97%) |
Age (years) | 36.3 (10) | 39 (10.7) | 35.9 (10.1) | 39.6 (11.1) |
Race/ethnicity | ||||
American Indian/Alaskan Native | 0 (0%) | 11 (1%) | 1 (1%) | 10 (1%) |
Asian or Pacific Islander | 4 (2%) | 12 (1%) | 0 (0%) | 10 (1%) |
Black | 89 (33%) | 221 (23%) | 56 (32%) | 244 (23%) |
Hispanic | 145 (53%) | 548 (58%) | 88 (51%) | 599 (57%) |
White | 28 (10%) | 136 (14%) | 23 (13%) | 155 (15%) |
Other** | 7 (3%) | 25 (3%) | 5 (3%) | 35 (3%) |
COVID-19 risk score (range 0–12)*** | 0.7 (1.3) | 1 (1.4) | 0.71 | 1.1 (1.5) |
Number of days of exposure between index case and close contact | 2.4 (1.2) | 2.2 (1.1) | 2.4 (1.2) | 2.3 (1.1) |
Prior infection | 84 (31%) | 356 (37%) | 59 (34%) | 448 (43%) |
Vaccination status | ||||
Unvaccinated | 273 (100%) | — | 173 (100%) | — |
Ad26.COV2 | — | 113 (12%) | — | 152 (15%) |
Completed only primary series | — | 58 (51%) | — | 70 (46%) |
Received booster or additional doses | — | 55 (49%) | — | 82 (54%) |
BNT162b2 | — | 188 (20%) | — | 193 (18%) |
Received one dose of primary series | — | 5 (3%) | — | 3 (2%) |
Completed only primary series | — | 55 (29%) | — | 43 (22%) |
Received booster or additional doses | — | 128 (68%) | — | 147 (76%) |
mRNA-1273 | — | 652 (68%) | — | 708 (67%) |
Received one dose of primary series | — | 13 (2%) | — | 25 (4%) |
Completed only primary series | — | 229 (35%) | — | 223 (31%) |
Received booster or additional doses | — | 412 (63%) | — | 462 (65%) |
