Table 2.
Positivity rates for Omicron and Delta among PCR tests performed between December 12 and 26, 2021. Rates shown in parentheses as means with 95% confidence intervals.
| Variant | All (vaccinated & unvaccinated, n = 33,416) | 0 dose: unvaccinated (n = 17914) | Vaccinated, 1 dose (n = 1,405) | Vaccinated, 2 doses ≥5 months before test (n = 1,186) | Vaccinated, 2 doses <5 months before test (n = 10,322) | Vaccinated, 3 doses (n = 2,589) |
|---|---|---|---|---|---|---|
| Delta (Ct ≤ 30) | 1,374 (0.041: 0.039, 0.043) | 954 (0.053: 0.05, 0.057) | 57 (0.041: 0.03, 0.051) | 32 (0.027: 0.018, 0.036) | 306 (0.03: 0.026, 0.033) | 25 (0.01: 0.006, 0.013) |
| Omicron (Ct ≤ 30) | 1,387 (0.042: 0.039, 0.044) | 793 (0.044: 0.041, 0.047) | 52 (0.037: 0.027, 0.047) | 58 (0.049: 0.037, 0.061) | 433 (0.042: 0.038, 0.046) | 51 (0.02: 0.014, 0.025) |
| Negative or Ct > 30 | 30,655 (0.917: 0.914, 0.92) | 16,167 (0.902: 0.898, 0.907) | 1,296 (0.922: 0.908, 0.936) | 1,096 (0.924: 0.909, 0.939) | 9,583 (0.928: 0.923, 0.933) | 2,513 (0.971: 0.964, 0.977) |
| Combined (Delta and Omicron) | 2,761 (0.083: 0.08, 0.086) | 1747 (0.098: 0.093, 0.102) | 109 (0.078: 0.064, 0.092) | 90 (0.076: 0.061, 0.091) | 739 (0.072: 0.067, 0.077) | 76 (0.029: 0.023, 0.036) |