Table 2. Estimated Comparative Effectiveness of the BNT162b2 and mRNA-1273 Vaccines during a Period Marked by Alpha-Variant Predominance (January 4–July 1, 2021).*.
| Covid-19 Outcome | No. of Events | 24-Wk Risk (95% CI) | Risk Difference (95% CI) | Risk Ratio (95% CI) | ||
|---|---|---|---|---|---|---|
| BNT162b2 | mRNA-1273 | BNT162b2 | mRNA-1273 | |||
| events/1000 persons | events/1000 persons | |||||
| Documented infection | 1135 | 881 | 5.75 (5.39 to 6.23) | 4.52 (4.17 to 4.84) | 1.23 (0.72 to 1.81) | 1.27 (1.15 to 1.42) |
| Symptomatic Covid-19 | 327 | 232 | 1.57 (1.42 to 1.76) | 1.13 (0.96 to 1.27) | 0.44 (0.25 to 0.70) | 1.39 (1.21 to 1.70) |
| Hospitalization | 258 | 153 | 1.33 (1.16 to 1.57) | 0.78 (0.64 to 0.91) | 0.55 (0.36 to 0.83) | 1.70 (1.42 to 2.24) |
| ICU admission | 77 | 48 | 0.36 (0.30 to 0.47) | 0.26 (0.17 to 0.36) | 0.10 (0.00 to 0.26) | 1.38 (1.01 to 2.42) |
| Death | 43 | 38 | 0.22 (0.15 to 0.27) | 0.20 (0.12 to 0.26) | 0.02 (−0.06 to 0.12) | 1.11 (0.69 to 1.91) |
*
Persons newly vaccinated with BNT162b2 were matched in a 1:1 ratio to persons newly vaccinated with mRNA-1273 according to the following variables: calendar date, age, sex, race, urbanicity of residence, and geographic location coded as categories of Veterans Integrated Services Network. CI denotes confidence interval, Covid-19 coronavirus disease 2019, and ICU intensive care unit.