Table 1.
Efficacy of the COVID-19 vaccines in protecting against infection and severe disease caused by VOCs. Despite impaired protection against infection, protection against severe disease is maintained. This might be underpinned by preservation of T-cell responses against the VOCs.
| Efficacy of the First-Generation Vaccines against VOCs. | |||
|---|---|---|---|
| Vaccine | Strain | Protection against Infection | Protection against Severe Disease (%, 95% CI) |
| Pfizer-BioNTech (BNT162b2) | SARS-CoV-2 (Wuhan-Hu-1) | 95% [36] | 96.7% (73.9–99.9) [37] |
| Delta (B.1.617.2) | Decreased neutralization titers by 2.2-fold compared to Wuhan-Hu-1 [38] | 93% (84–96) [39] | |
| Omicron (B.1.1.529) | Decrease in neutralization of 44-fold compared to Wuhan-Hu-1 [40] | 70% (62–76) [41] | |
| Moderna (mRNA-1273) | SARS-CoV-2 (Wuhan-Hu-1) | 93.2% (91.0–94.8) vs. symptomatic disease [42] | 100% (CI could not be estimated) [43] |
| Delta (B.1.617.2) | Only modestly decreased [44] | 95.9%unadj (86.9–98.7) [45] | |
| Omicron (B.1.1.529) | Decrease in neutralization of 33-fold compared to Wuhan-Hu-1 [40] | 81.1%unadj (29.8–94.9) [45] | |
| AstraZeneca (ChAdOx1) | SARS-CoV-2 (Wuhan-Hu-1) | 93% (at 83 IU/mL) [46] | 89.9% (83.5–93.8) [47] |
| Delta (B.1.617.2) | Eight-fold reduction in neutralizing titers compared to Wuhan-Hu-1 [48] | 92% (75–97) [49] | |
| Omicron (B.1.1.529) | Decrease in neutralization of 36-fold compared to Wuhan-Hu-1 [40] | Approximately 56% [50] | |
| J&J Janssen (Ad26.COV2.S) | SARS-CoV-2 (Wuhan-Hu-1) | 100% [51] | 57.7% (−2.6–82.5) [47] |
| Delta (B.1.617.2) | 1.6-fold reduction in neutralization sensitivity compared to Wuhan-Hu-1 [52] | 81% (75–86) [53] | |
| Omicron (B.1.1.529) | Majority of samples did not reveal neutralizing activity [27] | 74% (57–84) [41] | |