Vaccine Effectiveness against Omicron
Page last updated 19 October 2022
Key Points
Key Points are meant to be a scientific, factual summary of the available information that relates solely to the Pfizer-BioNTech COVID-19 Vaccine, as supported by referenced publications within this section. Conclusions should not be drawn from the inclusion or absence of information.
Omicron variant- lineage B1.1.529
- The Omicron variant (B.1.1.529) was initially reported in November 2021. Vaccine effectiveness (VE) against Omicron infection and other outcomes, such as severe disease, Emergency Department (ED)/ Urgent care (UC) visits, hospitalization, ICU admission, and death,1-9 has been observed to be lower than for other variants, such as Delta (B.1.617.2).1,2,5,7
| Outcome | VE% (95% CI) of 2 doses of BNT162b2, at listed times post last vaccine dose [Reference: Unvaccinated] | |||
|---|---|---|---|---|
| Adults ≥ 18 years | Children and adolescents, 5–18 years | |||
| Confirmed infection | ≥ 14 days: 41 (-17- 87) 10 | Ages 5–11 years | Ages 12–15 years | |
| 14–82 days: 31 (9–48) 2 | ≥ 14 days: 59 (22–79) 2 | |||
| Symptomatic infection | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology | Ages 5–11 years | Ages 12–15 years | |
| 14–30 days: 60 (55–65) 3 | 14–30 days: 60 (44–71) 3 | |||
| ED visits | ≥ 7 days: 47 (40–54) 1 ≥ 9 months: 31 (16–43) 1 |
Ages 5–11 years | Ages 12–15 years | Ages 16–17 years |
| 14–67 days: 51 (30–65) 4 | 14–149 days: 45 (30–57) 4 | 14–149 days: 34 (8–53) 4 | ||
| Hospitalization | ≥ 7 days: 62 (53–69) 1 ≥ 9 months: 41 (21–55) 1 |
Ages 5–11 years | Ages 12–18 years | |
| ≥ 14 days: 68 (42–82) 5 | ≥ 14 days: 40 (9–60) 5 | |||
| Death | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology | ||
- VE % (95% CI) against Omicron outcomes of interest has been reported in 1) recipients of 2 or 3 doses of BNT162b2 compared to unvaccinated individuals; 2) recipients of 3 doses compared to 2 doses of BNT162b2; 3) recipients of 4 doses compared to 3 doses of BNT162b2, at the listed times post last vaccine dose, are detailed below. The listed studies cannot be compared due to differences in study design and Methodology.
| Outcome | VE% (95% CI) range of 3 doses of BNT162b2, at listed times post last vaccine dose [Reference: Unvaccinated] | |
|---|---|---|
| Adults | Children and adolescents | |
| Confirmed infection | ≥ 7 days: 54 (23-73) 10 < 8 weeks : 75 (50-87) 10 16 weeks: 55 (5-69) 10 |
Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology |
| Symptomatic infection | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology | Ages 12–15 years |
| 2–6.5 weeks: 71 (66–76) 3 | ||
| ED visits | 14 days: 75 (70–79) 1 < 3 months : 77 (72–81) 1 ≥ 3 months: 53 (36–66) 1 |
Ages 16–17 years |
| ≥ 7 days: 81 (59–91) 4 | ||
| Hospitalization | ≥ 14 days: 82 (77–87) 1 < 3 months : 85 (80–89) 1 ≥ 3 months: 55 (28–71) 1 |
Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology |
| Death | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology |
| Outcome | VE% (95% CI) of 3rd(1st booster) dose of BNT162b2, at listed times post last vaccine dose [Reference: 2 doses] | VE% (95%CI) of 4th (2nd booster) dose of BNT162b2, at listed times post last vaccine dose [Reference: 3 doses] |
|---|---|---|
| Age ≥ 12 years | Age ≥ 60 years | |
| Confirmed infection | >7 days: 11 (7–14) 6 to 50 (42-56) 10 < 8 weeks : 66 (51-76) 10 >16 weeks: 55 (19-76) 10 |
7–30 days: 45 (44–47) 9 14–30 days: 52 (49–54) 9 |
| Symptomatic infection | > 7 days: 39 (23-52) 10 ≥ 14 days: 50 (48–52) 7 |
7–30 days: 55 (53–58) 9 14–30 days: 61 (58–64) 9 |
| Severe disease | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology | 7–30 days: 62 (50–74) 9 7–27 days: 73 (66–79) 8 14-30 days: 64 (48-77) 9 |
| Hospitalization | > 7 days: 50 (41–57) 6 | 7–30 days: 68 (59–74) 9 14–30 days: 72 (63–79) 9 |
| Hospitalization or death | ≥ 7 days: 77 (56–88) 7 | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology |
| ICU admission or death | > 7 days: 88 (68–96) 6 | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology |
| Death | Not reported in studies meeting this website’s inclusion criteria- please refer to Methodology | 7–30 days: 74 (50–90) 9 14–30 days: 76 (48–91) 9 |
Omicron variant- sublineage BA.1/ BA.2
- The effectiveness of protection provided by previous Omicron (B1.1.529) infection, vaccination with 2 or 3 doses of BNT162b2 and hybrid immunity (previous omicron infection and vaccination with BNT162b2) against symptomatic BA.1/BA.2 and any Omicron infection has been analyzed in a matched, test-negative, case-control study. 11
- The observed effectiveness of previous infection with Omicron lineage B1.1.529 alone against symptomatic BA.2 infection was 46.1% (95% CI, 39.5-51.9) and 50.2% (95% CI, 38.1-59.9) against symptomatic BA.1 infection.
- VE of 2 vaccine doses and no previous infection was -1.1% (95% CI, -7.1-4.6) against symptomatic BA.2 infection and -4.9% (95% CI, -16.4- 5.4) against symptomatic BA.1 infection; however, the majority of participants received 2nd vaccine dose > 6 months earlier.
- The highest observed effectiveness against symptomatic BA.2 infection was 77.3% (95% CI, 72.4- 81.4) and 74.4% (95% CI, 63.4- 82.2) against symptomatic BA.1 infection, observed in participants with previous infection and who had received 3 doses of vaccine.
- Previous infection alone, BNT162b2 vaccination alone and hybrid immunity all showed >70% effectiveness against severe, critical, or fatal COVID-19 infection.
- VE% (95% CI) of 2, and 3 doses of BNT162b2, at listed times post last vaccine dose, in immunocompetent adults, during a period of BA.1/BA.2 predominance, against symptomatic infection 11,12, and hospitalization12 or death12 were reported:
| Outcome | Variant | VE% (95%CI) of 2 doses of BNT162b2, at listed times post last vaccine dose [Reference: Unvaccinated] | VE% (95% CI) of 3rd (1st booster) dose of BNT162b2, at listed times post last vaccine dose [Reference: Unvaccinated] |
|---|---|---|---|
| Symptomatic infection | BA.1 | ≥ 14 days: -5 (-16 - 5) 11 1-3 months: 47 (33 - 57) 12 4-6 months: 9 (-4 - 20 ) 12 ≥ 7 months: -18 (-28 to -8) 12 |
≥ 7 days: 60 (53- 65) 11 < 1 month : 60 (51 - 67) 12 ≥ 1 month: 41 (31- 49) 12 |
| BA.2 | ≥ 14 days: -1 (-7 - 5) 11 1-3 months: 51 (43- 59) 12 4-6 months: 12 (4-20) 12 ≥ 7 months: -12 (-19 to -6) 12 |
≥ 7 days: 52 (48 - 56) 11 < 1 month : 44 (37 - 50) 12 ≥ 1 month: 40 (34 -46) 12 |
|
| Hospitalization or death | BA.1 and BA.2 | 1-6 months: 70.4 (45-84) 12 ≥ 7 months: 78 (68- 84) 12 |
1-6 weeks: 90.9 (79- 96) 12 ≥ 7 weeks: 90.1 (81- 95) 12 |
-
- VE against BA.1 and BA.2 symptomatic infection was similar and waned rapidly starting at 4 months after 2nd vaccine dose; VE against hospitalization or death was durable after a 2nd dose and most robust after a 3rd (booster) dose of BNT162b2.12
- Waning VE has been noted against Omicron infection and other outcomes, observed at > 3–6 months after receipt of last dose of BNT162b2. 1, 7-9, 12
- BNT162b2 vaccine, in the studies described in this summary, has been associated with reduction of risk against more severe Omicron outcomes, such as hospitalization or death, particularly for individuals who have received booster doses.1, 5, 6, 8, 9, 11, 12
References: (1) Tartof, Lancet Respir Med 2022, (2) Fowlkes,(3) Fleming-Dutra, (4) Klein, (5) Price, (6) Butt, CID May 2022, (7) Abu-Raddad, (8) Gazit, (9) Magen,(10) Richterman,(11) Altaranaweh,(12) Cheimatelly
