Table 1.
Effectiveness of COVID-19 vaccines against SARS-CoV-2 Omicron variant infection (infection (any type), symptomatic COVID-19, and severe COVID-19 (hospitalization, ICU admission, or death)).
| Vaccine(s) used for immunization | Range of adjusted vaccine effectiveness (95% CI)a,b,c | ||||
|---|---|---|---|---|---|
| ≈14 days d | >14 days up to 3 months | >3 months up to 6 months | >6 months | ||
| Infection (any type) | |||||
| Full primary immunization | mRNA-based (any) e | 16% (0–37) to 55.2% (23.5–73.7); (3–8) |
4.2% (-30.8–29.8) to 42.8% (33.8–50.7); (3, 4, 7) |
-76.5% (-95.3– -59.5) to 23% (15.8–29.6); (3, 4) |
8.6% (3.3–13.6); (4) |
| Vector-based (any) f | -4% (-97–43) to 11.4 (NR to NR); (6, 7) |
11.4% (NR to NR); (7) |
.. | .. | |
| Any vaccine h | -13% (-38–8) to 62% (58–66); (9–11) |
.. | -38% (-61– -18); (10) |
-16% (-62–17); (10) |
|
| Heterologous scheme g | .. | .. | .. | .. | |
| Booster immunization | mRNA-based (any) e | 34% (16–49) to 66% (36–81); (4–6, 8, 10, 12) i |
54.6% (30.4–70.4) i ; (3) | .. | .. |
| Vector-based (any) f | .. | .. | .. | .. | |
| Any vaccine h | 38% (29–46) to 76% (72–79); (6, 7, 9) i |
.. | .. | .. | |
| Heterologous scheme j | .. | .. | .. | .. | |
| Symptomatic COVID-19 | |||||
| Full primary immunization | mRNA-based (any) e | 41% (-57–77) to 76% (72–79); (13–15) |
44.8% (16–63.8) to 54% (49–58); (13, 14) |
13.3% (12.0–14.7) to 20.8% (13.7–27.4); (13, 14) |
-9.4% (-16.3–2.8) to 13% (3–22); (13, 14) |
| Vector-based (any) f | 6% (-103–56) to 49.8% (40.7–57.5); (13, 15) |
35.7% (27.7–42.8); (13) | 6.1% (4.1–8.1); (13) |
-1.0% (-2.4–0.3); (13) |
|
| Any vaccine h | 36% (24-45); (10) k |
12% (3-21); (10) k |
15% (8 – 22); (10) k |
2% (-17 – 17); (10) k |
|
| Heterologous scheme g | .. | .. | .. | .. | |
| Booster immunization | mRNA-based (any) e | 50.0% (41.2–57.4) to 73.9% (73.2–74.5); (12–14, 16) i |
43.7% (32.9–52.7) to 65.4% (63.9–66.9); (13, 14) |
.. | .. |
| Vector-based (any) f | 19% (-43–54); (15) |
.. | .. | .. | |
| Any vaccine h | 61% (56-65); (10) k |
.. | .. | .. | |
| Heterologous scheme j | 63.2% (62.6–63.8) to 70.7% (70.1–71.2); (13) |
54.0% (53.3–54.8) to 62.1% (61.1–63.1); (13) | .. | .. | |
| Severe COVID-19 (hospitalization, ICU admission, or death) | |||||
| Full primary immunization | mRNA-based (any) e | 3% (-114–56) to 81% (65–90); (4, 13, 14, 17–22) |
44% (-14–72) to 95% (57–99); (13, 22) |
57.3% (42.7–68.2) to 91% (31–99); (13, 22) |
34.9% (17.7–48.4) to 80.7% (71.3–87); (13, 14, 18, 20, 22) |
| Vector-based (any) f | 17% (-246–80) to 84% (-16–98); (19, 22) |
21% (-81–66) to 85% (54–95); (22, 24) |
-8% (-213–62) to 55.8% (34.1–70.3); (13, 22) |
32.7% (19.7–43.6); (13) | |
| Any vaccine h | 55% (-106–90) to 77% (-91–97); (6, 10, 23) |
37% (-71 – 77); (10) |
75% (51-87); (10) |
41 % (-22–72) to 86% (-12 – 98); (10, 23) |
|
| Heterologous scheme g | .. | .. | .. | .. | |
| Booster immunization | mRNA-based (any) e | 12% (-45–46) to 100% (71.4–100); (4, 10, 12–14, 18–22) i |
78% (76–80) to 93.7% (80.3–98); (13, 20, 22) |
.. | .. |
| Vector-based (any) f | 78% (76–80) to 84% (67–92); (22, 24) |
79% (76–81) to 84% (80–88); (22) |
.. | .. | |
| Any vaccine h | 60% (-163–90) to 956% (87-98); (6, 10, 23) |
.. | .. | .. | |
| Heterologous scheme j | 86.9% (82.8–90.1) to 91.4% (86.8–94.4); (13) |
85% (81.2–88) to 91.2% (82.8–95.5); (13) |
.. | .. | |
If not indicated otherwise, vaccine effectiveness (VE) estimates refer to the comparison of vaccinated (2 or 3 doses, respectively) vs. unvaccinated;
Provided VE estimates refer to the last reported time point per observation period (e.g. if studies reported VE after 2-4 and 5-9 weeks, the estimate of 5-9 weeks was included in the depicted effect range)
Several effect ranges are derived from single studies providing data for different vaccine types
time point closest to 14 days
Comirnaty or Spikevax
Vaxzevria or COVID-19-vaccine Janssen
1st dose with vector-based vaccine followed by prime booster dose of mRNA-based vaccine
Studies include recipients of different vaccine types, and data was not further stratified
Includes at least one study comparing booster vs. primary vaccination schedules (i.e., 3 vs. 2 doses)
1st dose with vector-based vaccine followed by prime booster dose, and 3rd dose of mRNA-based vaccine OR vector-based primary vaccination followed by one booster dose of mRNA-based vaccine
One study estimated VE against vaccinated individuals who received second dose before ≥25 weeks, because of insufficient unvaccinated individuals available for analysis (25). VE against symptomatic infection with Omicron and Delta was estimated for 16-49 and 50+ year old’s, respectively. Estimates are provided for all reported observation periods in Supplementary Material 2.