Supplementary Table 1.
Waning 2- and 3-Dose Immunity During the Delta and Omicron Waves∗
| Characteristic | Vaccine Effectiveness Against Hospitalization % (95% CI) |
|
|---|---|---|
| Delta | Omicron | |
| Any mRNA vaccine, 2 doses | 85 (84–85) | 55 (50–60) |
| <2 mo | 94 (92-96) | 71 (51-83) |
| 2-3 mo | 91 (89-92) | 65 (53-74) |
| 4 mo | 90 (89-92) | 58 (38-71) |
| ≥5 mo | 82 (82-83) | 54 (48-59) |
| Any mRNA vaccine, 3 doses | 95 (95-96) | 88 (86-90) |
| <2 mo | 96 (95-97) | 91 (88-93) |
| 2-3 mo | 93 (91-95) | 88 (85-90) |
| ≥4 mo | 76 (14-93) | 78 (67-85) |
∗
Findings from a test-negative case control study conducted by Ferdinands et al (2022)15 using data from 8 VISION Network sites, United States. Overall, vaccine effectiveness against hospitalization was lower during the Omicron than during the Delta wave, and administration of a third dose significantly increased protection against hospital admission.