Table 1. Vaccine Effectiveness against Symptomatic Covid-19 with the Delta Variant among Persons in England Who Received Two Doses of the ChAdOx1-S or BNT162b2 Vaccine, According to Weeks since Receipt of the Second Dose.*.
| Vaccine and Age Group | Vaccine Effectiveness (95% CI) | |||||
|---|---|---|---|---|---|---|
| 1 Wk | 2–9 Wk | 10–14 Wk | 15–19 Wk | ≥20 Wk† | ≥25 Wk | |
| percent | ||||||
| ChAdOx1-S | ||||||
| ≥16 Yr | 64.8 (63.8–65.8) | 67.6 (67.3–67.9) | 57.9 (57.5–58.4) | 50.5 (49.8–51.1) | 44.3 (43.2–45.4) | — |
| ≥65 Yr | 62.0 (45.1–73.7) | 59.1 (55.4–62.6) | 50.1 (46.1–53.8) | 43.8 (39.3–47.9) | 38.0 (32.7–42.8) | 27.8 (16.3–37.8) |
| 40–64 Yr | 55.6 (54.0–57.1) | 62.0 (61.3–62.6) | 57.4 (56.6–58.2) | 55.4 (54.4–56.3) | 56.7 (55.0–58.4) | — |
| BNT162b2 | ||||||
| ≥16 Yr | 92.3 (92.0–92.6) | 89.7 (89.5–89.8) | 80.7 (80.3–81.0) | 72.8 (72.4–73.2) | 66.3 (65.7–66.9) | — |
| ≥65 Yr | 60.0 (25.4–78.6) | 79.6 (77.0–81.8) | 69.4 (66.7–71.8) | 63.1 (60.2–65.9) | 54.9 (51.1–58.5) | 51.8 (45.4–57.4) |
| 40–64 Yr | 87.7 (86.0–89.2) | 84.3 (83.7–84.8) | 77.3 (76.6–78.0) | 72.1 (71.2–72.9) | 69.2 (67.7–70.6) | — |
| 16–39 Yr | 92.4 (92.1–92.7) | 89.5 (89.3–89.7) | 72.9 (71.5–74.1) | 69.8 (52.4–80.8) | — | — |
*
CI denotes confidence interval, and Covid-19 coronavirus disease 2019.
†
Results in this column for persons 65 years of age or older are only for the period of 20 to 24 weeks after receipt of the second vaccine dose.