TABLE 3.
Two‐ and three‐dose vaccine effectiveness during SARS‐CoV‐2 Delta variant or Omicron variant associated symptomatic COVID‐19 illness among adults seeking outpatient medical care or SARS‐CoV‐2 clinical testing, US Flu VE Network, October 2021–February 2022
| SARS‐CoV‐2 positive | SARS‐CoV‐2 negative | Unadjusted VE | Adjusted a VE | |||||
|---|---|---|---|---|---|---|---|---|
| Vaccinated/Total | (%) | Vaccinated/Total | (%) | VE | (95% CI) | VE | (95% CI) | |
| Overall | ||||||||
| 2‐dose | 822/1289 | (64) | 1115/1446 | (77) | 48 | (38 to 56) | 48 | (37 to 57) |
| 3‐dose | 350/817 | (43) | 762/1093 | (70) | 67 | (61 to 73) | 78 | (72 to 83) |
| Delta b | ||||||||
| 2‐dose | 327/552 | (59) | 763/942 | (81) | 66 | (57 to 73) | 63 | (51 to 72) |
| 14–149 days | 14/239 | (6) | 106/285 | (37) | 89 | (81 to 94) | 89 | (78 to 94) |
| ≥150 days | 313/538 | (58) | 657/836 | (79) | 62 | (52 to 70) | 58 | (44 to 68) |
| 3‐dose | 22/247 | (9) | 259/438 | (59) | 93 | (89 to 96) | 96 | (93 to 98) |
| Omicron b | ||||||||
| 2‐dose | 464/684 | (68) | 257/380 | (68) | 0 | (−32 to 23) | 21 | (−6 to 41) |
| 14–149 days | 69/289 | (24) | 53/176 | (30) | 27 | (−11 to 52) | 45 | (14 to 66) |
| ≥150 days | 395/615 | (64) | 204/327 | (62) | −8 | (−43 to 18) | 11 | (−21 to 35) |
| 3‐dose | 322/542 | (59) | 408/531 | (77) | 56 | (43 to 66) | 62 | (48 to 72) |
a
Logistic regression model adjusted for age, site, illness onset week, and prior infection status.
b
Totals in variant‐specific periods may not add up to overall total as a transition period was included in the overall estimates but removed in the variant‐specific periods.