The DOI matches its Crossref record; 28 of the 29 references it cites were found in a registry or an index; 11 of the 44 sources its claims cite were checked for support.
Effectiveness of COVID-19 vaccines against the Omicron (B.1.1.529) variant of concern
Open accessAbstract
Background: A rapid increase in cases due to the SARS-CoV-2 Omicron (B.1.1.529) variant in highly vaccinated populations has raised concerns about the effectiveness of current vaccines. Methods: We used a test-negative case-control design to estimate vaccine effectiveness (VE) against symptomatic disease caused by the Omicron and Delta variants in England. VE was calculated after primary immunisation with two BNT162b2 or ChAdOx1 doses, and at 2+ weeks following a BNT162b2 booster. Results: Between 27 November and 06 December 2021, 581 and 56,439 eligible Omicron and Delta cases respectively were identified. There were 130,867 eligible test-negative controls. There was no effect against Omicron from 15 weeks after two ChAdOx1 doses, while VE after two BNT162b2 doses was 88.0% (95%CI: 65.9 to 95.8%) 2-9 weeks after dose 2, dropping to between 34 and 37% from 15 weeks post dose 2.From two weeks after a BNT162b2 booster, VE increased to 71.4% (95%CI: 41.8 to 86.0%) for ChAdOx1 primary course recipients and 75.5% (95%CI: 56.1 to 86.3%) for BNT162b2 primary course recipients. For cases with Delta, VE was 41.8% (95%CI: 39.4-44.1%) at 25+ weeks after two ChAdOx1 doses, increasing to 93.8% (95%CI: 93.2-94.3%) after a BNT162b2 booster. With a BNT162b2 primary course, VE was 63.5% (95%CI: 61.4 to 65.5%) 25+ weeks after dose 2, increasing to 92.6% (95%CI: 92.0-93.1%) two weeks after the booster. Conclusions: Primary immunisation with two BNT162b2 or ChAdOx1 doses provided no or limited protection against symptomatic disease with the Omicron variant. Boosting with BNT162b2 following either primary course significantly increased protection.
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TL;DR
In England, a test-negative case–control study found that COVID-19 vaccine effectiveness against symptomatic omicron infection was substantially lower than against delta and waned rapidly after two doses. Booster doses with BNT162b2 or mRNA-1273 restored substantial protection, but this protection also declined over the short follow-up period.
Key findings
- Among 886,774 eligible omicron cases, 204,154 delta cases, and 1,572,621 test-negative controls, vaccine effectiveness against symptomatic disease was higher for delta than omicron at all time points and for all primary-course/booster combinations.
- After two BNT162b2 doses, omicron vaccine effectiveness was 65.5% (95% CI, 63.9–67.0) at 2–4 weeks, falling to 8.8% (95% CI, 7.0–10.5) at ≥25 weeks; after two ChAdOx1 nCoV-19 doses, no effect against omicron was noted from 20 weeks.
- A BNT162b2 booster after ChAdOx1 nCoV-19 increased omicron vaccine effectiveness to 62.4% (95% CI, 61.8–63.0) at 2–4 weeks, decreasing to 39.6% (95% CI, 38.0–41.1) at ≥10 weeks; after BNT162b2 primary course, it increased to 67.2% (95% CI, 66.5–67.8) and declined to 45.7% (95% CI, 44.7–46.7).
- An mRNA-1273 booster after ChAdOx1 nCoV-19 increased omicron vaccine effectiveness to 70.1% (95% CI, 69.5–70.7) at 2–4 weeks and decreased to 60.9% (95% CI, 59.7–62.1) at 5–9 weeks; after BNT162b2 primary course, it increased to 73.9% (95% CI, 73.1–74.6) and fell to 64.4% (95% CI, 62.6–66.1) at 5–9 weeks.
Methods
- Test-negative case–control design in England comparing odds of vaccination in symptomatic PCR-positive SARS-CoV-2 cases with symptomatic test-negative controls, using data from November 27, 2021, to January 12, 2022.
- Cases were classified as omicron or delta by whole-genome sequencing, genotyping, or S target–negative status; vaccination data came from the National Immunization Management System, with 91.8% of eligible tests linked.
- Logistic regression estimated vaccine effectiveness adjusted for age, sex, deprivation, race/ethnic group, foreign travel, geographic region, test date, health/social care worker status, clinical risk group, clinically extremely vulnerable status, and previous positive test.
Limitations
- The authors state they could not determine protection against severe disease because of the small number of omicron hospitalizations and the natural lag between infection and severe outcomes.
- The authors note possible residual confounding from travelers and contacts of travelers, uncertainty from relatively small omicron case numbers, inability to break down estimates by age and clinical risk group, a small and potentially different unvaccinated comparator group, short follow-up after booster vaccination, and possible misclassification from PCR testing and S target–negative status.
- The authors also state that populations receiving different vaccines or boosters differed, and that the ChAdOx1 nCoV-19 booster analysis was particularly likely to be biased because this vaccine was not recommended as a booster in the United Kingdom; the observational design makes confounding by indication evident.
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Claims the paper makes
21 Own result · 14 Own method · 12 Not checked yet · 11 Own interpretation · 3 Partly supported · 1 Supported so far · accuracy not yet measured
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In the paper
“These findings are consistent with neutralization data for the omicron variant.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Supportedcites [3] Cele S , Jackson L , Khan K , Khoury D , Moyo-Gwete T , Tegally H , et al. SARS-CoV-2 Omicron has extensive but incomplete escape of Pfizer BNT162b2 elicited neutralization and requires ACE2 for infection. medRxiv. 2021:2021.12.08.21267417. source
The paper reports live-virus neutralization data for Omicron in its Abstract, including a 22-fold lower neutralization titer than for ancestral virus. The cited source therefore contains the Omicron neutralization data invoked by the sentence; the citing document’s unspecified “findings” cannot be compared more closely from the text provided. (LLM, conf=0.85)
- Supportedcites [4] Wilhelm A , Widera M , Grikscheit K , Toptan T , Schenk B , Pallas C , et al. Reduced Neutralization of SARS-CoV-2 Omicron Variant by Vaccine Sera and monoclonal antibodies. medRxiv. 2021:2021.12.07.21267432. source
The Results describe neutralization measurements for Omicron, and the Discussion reports reduced sensitivity of Omicron BA.1 and BA.2 to antibody neutralization. The citing sentence does not specify what its own findings were, so this confirms that the source provides relevant Omicron neutralization data, not the consistency of an unstated comparison. No page number is available in our copy. (LLM, conf=0.88)
- Could not verifycites [5] Khoury DS , Cromer D , Reynaldi A , Schlub TE , Wheatley AK , Juno JA , et al. Neutralizing antibody levels are highly predictive of immune protection from symptomatic SARS-CoV-2 infection. Nature medicine. 2021. sourceExperimental — accuracy not yet measured
The Methods (p. 9) model hypothetical reductions in neutralization against SARS-CoV-2 variants, but do not identify omicron or present omicron neutralization data. A search for omicron-specific data found no passage in our copy that could establish the claimed consistency. (LLM, conf=0.76)
- Not checked yetcites [34]
plaincorrelational- Asserted: passes — The authors put it forward as true.
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In the paper
“After a BNT162b2 primary course, the mRNA-1273 booster increased vaccine effectiveness to 73.9% (95% CI, 73.1 to 74.6) at 2 to 4 weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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In the paper
“vaccine effectiveness fell to 64.4% (95% CI, 62.6 to 66.1) at 5 to 9 weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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In the paper
“The vaccine effectiveness of two doses of mRNA-1273 vaccine had a similar reduction over time from 75.1% (95% CI, 70.8 to 78.7) after 2 to 4 weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Omicron Variant
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In the paper
“With the delta variant, vaccine effectiveness after two doses of ChAdOx1 nCoV-19 primary course started at 82.8% (95% confidence interval [CI], 74.5 to 88.4) after 2 to 4 weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Delta Variant
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“dropping to 8.8% (95% CI, 7.0 to 10.5) at 25 or more weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“but waned to 43.5% (95% CI, 42.4 to 44.5) after 25 or more weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Delta Variant
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“before declining to 45.7% (95% CI, 44.7 to 46.7) at 10 or more weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“Among ChAdOx1 nCoV-19 primary course recipients, vaccine effectiveness increased to 62.4% (95% CI, 61.8 to 63.0) at 2 to 4 weeks after a BNT162b2 booster”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“Among BNT162b2 primary course recipients, vaccine effectiveness increased to 67.2% (95% CI, 66.5 to 67.8) at 2 to 4 weeks after a BNT162b2 booster”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“vaccine effectiveness after two BNT162b2 doses was 65.5% (95% confidence interval [CI], 63.9 to 67.0) at 2 to 4 weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“to 14.9% (95% CI, 3.9 to 24.7) after 25 or more weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Omicron Variant
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“and 66.3% (95% CI, 63.7 to 68.8) at 2 to 4 weeks after an mRNA-1273 booster”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Omicron Variant
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“After an mRNA-1273 primary course, vaccine effectiveness increased to 64.9% (95% CI, 62.3 to 67.3) at 2 to 4 weeks after a BNT162b2 booster”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Omicron Variant
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“before decreasing to 39.6% (95% CI, 38.0 to 41.1) at 10 or more weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“dropping to 15.4% (95% CI, 14.2 to 16.6) after 15 to 19 weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Omicron Variant
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“Vaccine effectiveness after a ChAdOx1 nCoV-19 primary course increased to 70.1% (95% CI, 69.5 to 70.7) at 2 to 4 weeks after an mRNA-1273 booster”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“At all time points investigated and for all combinations of primary course and booster vaccines, vaccine effectiveness against symptomatic disease was higher for the delta variant than for the omicron variant.”
- Also stated in: § Vaccine Effectiveness, Omicron Variant · plain
“Vaccine effectiveness was lower for the omicron variant than for the delta variant at all intervals after vaccination and for all combinations of primary courses and booster doses investigated.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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In the paper
“Waning efficacy was most notable against the omicron variant, for which the vaccine effectiveness was 46.7% (95% CI, 34.3 to 56.7) at 5 to 9 weeks.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Omicron Variant
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In the paper
“and decreased to 60.9% (95% CI, 59.7 to 62.1) at 5 to 9 weeks”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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“No effect against the omicron variant was noted from 20 weeks after two ChAdOx1 nCoV-19 doses”
- Also stated in: § Vaccine Effectiveness, Omicron Variant · hedged
“Among those who had received two ChAdOx1 nCoV-19 doses, almost no protective effect of vaccination against symptomatic disease caused by the omicron variant was noted from 20 to 24 weeks after the second dose.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Results
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- Also stated in: § Vaccine Effectiveness, Omicron Variant · hedged
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In the paper
“Our findings indicate that two doses of vaccination with BNT162b2 or ChAdOx1 nCoV-19 are insufficient to give adequate levels of protection against infection with the omicron variant and mild disease.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
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“but that protection waned over time”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
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In the paper
“on the basis of experience with other variants and early estimates of hospitalization rates, vaccine effectiveness against severe disease is likely to be substantially higher than the estimates against symptomatic disease”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Not checked yetcites [19] 2021, Partial resistance of SARS-CoV-2 Delta variants to vaccine-elicited antibodies and convalescent sera, iScience source
- Not checked yetcites [36]
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In the paper
“Primary immunization with two doses of ChAdOx1 nCoV-19 or BNT162b2 vaccine provided limited protection against symptomatic disease caused by the omicron variant.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
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“Boosters will probably offer even greater levels of protection against severe and fatal disease.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
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“Previous experience with the delta variant in the United Kingdom suggested that protection against hospitalization after two doses of vaccine was well maintained.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Not checked yetcites [19] 2021, Partial resistance of SARS-CoV-2 Delta variants to vaccine-elicited antibodies and convalescent sera, iScience source
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In the paper
“A BNT162b2 or mRNA-1273 booster after either the ChAdOx1 nCoV-19 or BNT162b2 primary course substantially increased protection”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
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In the paper
“In this analysis that covers all ages, this type of confounding may be less of an issue than in analyses restricted to elderly populations.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
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“During this early period of circulation of the new variant, a large proportion of cases occurred among travelers.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
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“The populations that have received different vaccines as a primary course are different.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
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In the paper
“Our findings indicate that vaccine effectiveness against symptomatic disease caused by the omicron variant is substantially lower than with the delta variant.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
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“We used a test-negative case–control design to estimate vaccine effectiveness against symptomatic Covid-19 caused by the omicron variant as compared with the delta variant in persons 18 years of age or older.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Study Design
What the sources say
- Not checked yetcites [17] Pouwels KB , Pritchard E , Matthews PC , Stoesser N , Eyre DW , Vihta K-D , et al. Impact of Delta on viral burden and vaccine effectiveness against new SARS-CoV-2 infections in the UK. medRxiv. 2021:2021.08.18.21262237. source
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“A total of 91.8% of eligible tests could be linked to the NIMS.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Data Sources
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What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“We therefore used cases tested on or after November 27, when the positive predictive value was more than 80%.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Descriptive Characteristics
plaincorrelational- Asserted: passes — The authors put it forward as true.
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A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Although adjustments were made for age and clinical risk factors, these age differences may explain some of the differences in the findings for the primary course”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“We are unable to determine protection against severe forms of disease using the test-negative case–control method here owing to the small number of omicron cases resulting in hospitalization so far in our data set and the natural lag between infection and more severe outcomes.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
plain- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“Higher neutralizing activity was observed after a booster dose.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Not checked yetcites [3] Cele S , Jackson L , Khan K , Khoury D , Moyo-Gwete T , Tegally H , et al. SARS-CoV-2 Omicron has extensive but incomplete escape of Pfizer BNT162b2 elicited neutralization and requires ACE2 for infection. medRxiv. 2021:2021.12.08.21267417. source
- Not checked yetcites [4] Wilhelm A , Widera M , Grikscheit K , Toptan T , Schenk B , Pallas C , et al. Reduced Neutralization of SARS-CoV-2 Omicron Variant by Vaccine Sera and monoclonal antibodies. medRxiv. 2021:2021.12.07.21267432. source
- Not checked yetcites [34]
plaindirect- Asserted: passes — The authors put it forward as true.
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What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Data were restricted to persons who had reported symptoms and gave a symptom-onset date within the 10 days before testing to account for reduced PCR sensitivity beyond this period in an infection event.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Data Sources
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“Cellular immunity is also likely to play an important role in protection against SARS-CoV-2 variants.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Not checked yetcites [35]
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- It may state two separate claims as one. 19
- Probably not a substantial claim. 3
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Emerging laboratory data indicate a substantially reduced neutralizing antibody response to the omicron variant as compared with the original strain of SARS-CoV-2 or the delta (B.1.617.2) variant in vaccinated persons, although booster doses improved neutralizing activity.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
What the sources say
- Not checked yetcites [3] Cele S , Jackson L , Khan K , Khoury D , Moyo-Gwete T , Tegally H , et al. SARS-CoV-2 Omicron has extensive but incomplete escape of Pfizer BNT162b2 elicited neutralization and requires ACE2 for infection. medRxiv. 2021:2021.12.08.21267417. source
- Not checked yetcites [4] Wilhelm A , Widera M , Grikscheit K , Toptan T , Schenk B , Pallas C , et al. Reduced Neutralization of SARS-CoV-2 Omicron Variant by Vaccine Sera and monoclonal antibodies. medRxiv. 2021:2021.12.07.21267432. source
- Partly supportedcites [5] Khoury DS , Cromer D , Reynaldi A , Schlub TE , Wheatley AK , Juno JA , et al. Neutralizing antibody levels are highly predictive of immune protection from symptomatic SARS-CoV-2 infection. Nature medicine. 2021. sourceExperimental — accuracy not yet measured
Split into 2 atoms — 0 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 1 unverifiable. Expand the claim to see per-atom verdicts.
hedgeddirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
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It may state two separate claims as one.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Coronavirus disease 2019 (Covid-19) vaccines are highly effective against symptomatic disease and, more so, against severe disease and fatal outcomes caused by the original strain of SARS-CoV-2 as well as the alpha (B.1.1.7) variant that predominated in early 2021.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
What the sources say
- Not checked yetcites [9] Voysey M , Clemens SAC , Madhi SA , Weckx LY , Folegatti PM , Aley PK , et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. The Lancet. 2020.
- Not checked yetcites [10] 2020, Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine, New England Journal of Medicine
- Partly supportedcites [11] sourceExperimental — accuracy not yet measured
The Discussion reports substantial protection against symptomatic disease and greater estimated protection against hospital admission and death in adults aged 70 or older in England. The Results report similar effects on symptomatic infection with and without the B.1.1.7 proxy. The paper does not establish protection against severe or fatal outcomes separately for the original strain and alpha variant, and says it was too early to assess ChAdOx1-S’s effect on mortality. (LLM, conf=0.88)
- Partly supportedcites [12] 2021, COVID-19 vaccine coverage in health-care workers in England and effectiveness of BNT162b2 mRNA vaccine against infection (SIREN): a prospective, multicentre, cohort study, The Lancet sourceExperimental — accuracy not yet measured
The Discussion reports 70% effectiveness against infection after one BNT162b2 dose and 85% after two doses, and says the findings suggest effectiveness against the predominant B.1.1.7 (alpha) variant. But the study could not estimate effectiveness separately for symptomatic infection, and our copy does not establish greater protection against severe disease or death, or effectiveness across COVID-19 vaccines and both strains. (LLM, conf=0.88)
- Partly supportedcites [13] 2021, Interim estimates of vaccine effectiveness of BNT162b2 and mRNA-1273 COVID-19 vaccines in preventing SARS-CoV-2 infection among health care personnel, first responders, and other essential and frontline workers—eight US locations, December 2020–March 2021, Morbidity and Mortality Weekly Report sourceExperimental — accuracy not yet measured
The opening section says Phase III trials found the mRNA vaccines effective against symptomatic COVID-19, and the Discussion reports 90% effectiveness against infection regardless of symptoms in the studied workers. The Discussion mentions other studies of severe COVID-19 but does not establish greater effectiveness against severe disease than symptomatic disease. This study recorded no deaths and says viral genetic characterization was still planned, so it does not support the claims about fatal outcomes or effectiveness against the original strain and alpha variant specifically. (LLM, conf=0.88)
- Partly supportedcites [14] Dagan N , Barda N , Kepten E , Miron O , Perchik S , Katz MA , et al. BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting. The New England journal of medicine. 2021. sourceExperimental — accuracy not yet measured
The Results (Vaccine Effectiveness; page unavailable) report high effectiveness of BNT162b2 against symptomatic illness, severe disease, and death, but do not establish that protection against severe disease was consistently greater than protection against symptomatic illness. The Discussion (page unavailable) says the study averaged effectiveness across multiple strains and suggests effectiveness against B.1.1.7; it explicitly says it cannot provide a variant-specific estimate. The claim also generalizes from this one vaccine to Covid-19 vaccines broadly. (LLM, conf=0.88)
- Partly supportedcites [15] Abu-Raddad LJ , Chemaitelly H , Butt AA . Effectiveness of the BNT162b2 Covid-19 Vaccine against the B.1.1.7 and B.1.351 Variants. New England Journal of Medicine. 2021. sourceExperimental — accuracy not yet measured
The main text and Table 1 report high effectiveness of two-dose BNT162b2 against documented B.1.1.7 infection and severe, critical, or fatal disease. But the infection estimate is not specific to symptomatic disease, and this study does not separately establish protection against severe outcomes caused by the original strain. Its results concern BNT162b2, not Covid-19 vaccines generally; page numbers were not provided in our copy. (LLM, conf=0.88)
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
The cited sources support only part of this claim — read each source’s verdict below.
In the paper
“Modest reductions in vaccine effectiveness against infection and mild disease have been observed with the beta (B.1.351) and delta variants, although effectiveness against severe disease has remained high for at least 6 months after primary immunization with two Covid-19 vaccine doses.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
What the sources say
- Partly supportedcites [16] sourceExperimental — accuracy not yet measured
Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
- Not checked yetcites [17] Pouwels KB , Pritchard E , Matthews PC , Stoesser N , Eyre DW , Vihta K-D , et al. Impact of Delta on viral burden and vaccine effectiveness against new SARS-CoV-2 infections in the UK. medRxiv. 2021:2021.08.18.21262237. source
- Partly supportedcites [18] Andrews N , Gower C , Stowe J , Tessier E , Kirsebom F , Gallagher E , et al. Duration of Protection of COVID-19 Vaccines Against Mild and Severe Disease. New England Journal of Medicine (In Press). 2021. sourceExperimental — accuracy not yet measured
Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
- Not checked yetcites [19] 2021, Partial resistance of SARS-CoV-2 Delta variants to vaccine-elicited antibodies and convalescent sera, iScience source
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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It may state two separate claims as one.
- Partly supported
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“After a booster with an mRNA vaccine, vaccine effectiveness reached more than 95% with any of the primary courses and remained high up to the longest follow-up points (maximum, ≥10 weeks).”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Results > Vaccine Effectiveness, Delta Variant
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“With previous variants, vaccine effectiveness against severe disease, including hospitalization and death, has been higher and has been retained for a longer period than effectiveness against mild disease.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Boosting with BNT162b2 or mRNA-1273 provided a substantial increase in protection against mild disease, although waning occurred over time.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“Neutralizing antibodies correlate with protection against reinfection and vaccine effectiveness against infection”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
What the sources say
- Not checked yetcites [6] Addetia A , Crawford KHD , Dingens A , Zhu H , Roychoudhury P , Huang ML , et al. Neutralizing Antibodies Correlate with Protection from SARS-CoV-2 in Humans during a Fishery Vessel Outbreak with a High Attack Rate. Journal of clinical microbiology. 2020;58(11). source
- Not checked yetcites [7] 2021, Reinfection with new variants of SARS-CoV-2 after natural infection: a prospective observational cohort in 13 care homes in England, The Lancet Healthy longevity source
- Not checked yetcites [8] Polack FP , Thomas SJ , Kitchin N , Absalon J , Gurtman A , Lockhart S , et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. New England Journal of Medicine. 2020. source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“However, third (booster) doses provide a rapid and substantial increase in protection against both mild and severe disease.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
What the sources say
- Not checked yetcites [19] 2021, Partial resistance of SARS-CoV-2 Delta variants to vaccine-elicited antibodies and convalescent sera, iScience source
- Not checked yetcites [21] Israel A , Merzon E , Schäffer AA , Shenhar Y , Green I , Golan-Cohen A , et al. Elapsed time since BNT162b2 vaccine and risk of SARS-CoV-2 infection in a large cohort. medRxiv. 2021:2021.08.03.21261496. source
- Not checked yetcites [22] Mizrahi B , Lotan R , Kalkstein N , Peretz A , Perez G , Ben-Tov A , et al. Correlation of SARS-CoV-2 Breakthrough Infections to Time-from-vaccine; Preliminary Study. medRxiv. 2021:2021.07.29.21261317. source
- Not checked yetcites [23] Andrews N , Stowe J , Kirsebom F , Gower C , Ramsay M , Bernal JL . Effectiveness of BNT162b2 (Comirnaty, Pfizer-BioNTech) COVID-19 booster vaccine against covid-19 related symptoms in England: test negative case-control study. medRxiv. 2021:2021.11.15.21266341. source
- Not checked yetcites [24] 2021, Protection of BNT162b2 Vaccine Booster against Covid-19 in Israel, New England Journal of Medicine source
- Not checked yetcites [25] UK Health Security Agency. SARS-CoV-2 variants of concern and variants under investigation in England: Omicron VOC-21NOV-01 (B.1.1.529) update on cases, S gene target failure and risk assessment 2021 [Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1039644/Omicron_SGTF_case_update_FINAL.pdf.
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
In the paper
“Waning of protection has been observed with time since vaccination, especially with the delta variant, which is able to at least partially evade natural and vaccine-induced immunity.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Abstract > Conclusions
What the sources say
- Not checked yetcites [20] Goldberg Y , Mandel M , Bar-On YM , Bodenheimer O , Freedman L , Haas EJ , et al. Waning immunity of the BNT162b2 vaccine: A nationwide study from Israel. medRxiv. 2021:2021.08.24.21262423. source
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Owing to the relatively small number of omicron cases in the United Kingdom, our estimates are subject to considerable uncertainty, and we are unable to break down estimates according to population characteristics that may affect vaccine effectiveness (e.g., age and clinical risk group).”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
plain- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
In the paper
“In serum specimens obtained from recipients of two doses of ChAdOx1 nCoV-19, a greater reduction in neutralizing activity was observed, with a high proportion of postvaccination serum samples having neutralizing activity below the limit of quantification in the assay.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Not checked yetcites [34]
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
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It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“In this analysis, our comparator group is unvaccinated persons, who make up a very small proportion of persons in several age cohorts. These persons are likely to differ from the general population according to characteristics that could confound our estimates of vaccine effectiveness.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
hedgedcorrelational- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“After two doses, vaccine effectiveness waned rapidly, with very limited vaccine effects seen from 20 weeks after the second dose of any vaccine.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Booster doses have only recently been rolled out in England; therefore, we are able to estimate vaccine effectiveness for only a short period after booster vaccination, and we do not have information on the duration of protection after a booster dose.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“The analysis with ChAdOx1 nCoV-19 boosters is particularly likely to be subject to bias because this vaccine was not recommended as a booster in the United Kingdom; therefore, some misclassification may have occurred”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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It may state two separate claims as one.
In the paper
“Cellular immune responses are likely to play a relatively more important role in protection as antibodies wane with time since infection or vaccination; antibody waning may increase the risk of SARS-CoV-2 infection even as cellular immunity probably limits progression to severe disease.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Not checked yetcites [35]
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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It may state two separate claims as one.
None of the sources cited for this claim have been checked yet.
In the paper
“South African, German, and U.K. studies indicate a reduction in neutralizing activity by a factor of 20 to 40 in serum specimens obtained from recipients of two doses of BNT162b2 as compared with neutralization against early pandemic viruses and by a factor of at least 10 as compared with neutralization against the delta variant.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
What the sources say
- Not checked yetcites [3] Cele S , Jackson L , Khan K , Khoury D , Moyo-Gwete T , Tegally H , et al. SARS-CoV-2 Omicron has extensive but incomplete escape of Pfizer BNT162b2 elicited neutralization and requires ACE2 for infection. medRxiv. 2021:2021.12.08.21267417. source
- Not checked yetcites [4] Wilhelm A , Widera M , Grikscheit K , Toptan T , Schenk B , Pallas C , et al. Reduced Neutralization of SARS-CoV-2 Omicron Variant by Vaccine Sera and monoclonal antibodies. medRxiv. 2021:2021.12.07.21267432. source
- Not checked yetcites [5] Khoury DS , Cromer D , Reynaldi A , Schlub TE , Wheatley AK , Juno JA , et al. Neutralizing antibody levels are highly predictive of immune protection from symptomatic SARS-CoV-2 infection. Nature medicine. 2021. source
- Not checked yetcites [34]
hedgeddirect- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“The large scale of testing and sequencing in the United Kingdom, as well as the use of a national vaccination register, has enabled rapid evaluation of vaccine effectiveness against symptomatic infection with the omicron variant.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Negative tests taken within 21 days before a subsequent positive test were also excluded because chances were high that these were false negatives.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Data Sources
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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Probably not a substantial claim.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Booster doses resulted in a substantial increase in protection against mild infection; however, waning of protection against symptomatic disease was also seen after booster doses.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
plaindirect- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“Some misclassification may also have occurred owing to both imperfect sensitivity and specificity of PCR testing, as well as the use of S target–negative status to identify omicron cases.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
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- Load-bearing: fails — The paper’s conclusions may not depend on it.
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Probably not a substantial claim. The paper’s conclusions may not depend on it.
What the paper did — it cites no source for this, so there is none to check. The quote shows it is in the paper.
In the paper
“not all travelers may have been excluded, and contacts of travelers will not have been identified. This group is likely to have different exposure than the wider population and may also have different levels of vaccine coverage. Therefore, residual confounding may be present.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Discussion
hedgedconditional- Asserted: passes — The authors put it forward as true.
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It may state two separate claims as one.
The paper relies on this without support.
Recent analyses using different control groups have shown good concordance between analyses using an unvaccinated control group and analyses estimating relative vaccine effectiveness among persons who have received a booster dose as compared with those who have received two doses.
“Furthermore, recent analyses using different control groups have shown good concordance between analyses using an unvaccinated control group and analyses estimating relative vaccine effectiveness among persons who have received a booster dose as compared with those who have received two doses.”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“These vaccines are effective, but the immune response wanes in the months immediately following administration.8,9”
From Immunogenicity and safety of a booster dose of a self-amplifying RNA COVID-19 vaccine (ARCT-154) versus BNT162b2 mRNA COVID-19 vaccine: a double-blind, multicentre, randomised, controlled, phase 3, non-inferiority trial (2024) · cites this paper as [8]
Experimental — accuracy not yet measuredThe cited source says what the claim attributes to it.
In the citing paper
“The cohort from England also documented rapid waning of 2-dose mRNA protection with minimal vaccine protection observed 20 weeks after the second dose.”
The cited source says what the claim attributes to it.
In the citing paper
“Real-word VE studies published during the periods of circulation of these two variants showed differences in vaccine-induced protection against Delta and Omicron variants-related infections, with less protection against Omicron than Delta [18-22].”
In the citing paper
“Prior work has demonstrated Omicron BA. 1/2's significant immune escape properties [13][14][15][16][17] .”
From Rapidly shifting immunologic landscape and severity of SARS-CoV-2 in the Omicron era in South Africa (2023) · cites this paper as [14]
In the citing paper
“These findings are explained by the short-lived protection of primary-series vaccination against omicron infections3,27 and the more durable protection from natural infection,2,28 as confirmed by the additional analysis of protection as a function of time after previous infection or vaccination (Figure 3).”
From Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections (2022) · cites this paper as [27]
In the citing paper
“Notwithstanding these limitations, findings were consistent with those of other studies of vaccine effectiveness against omicron infection (BA.1 or BA.2 subvariants were not specified).27,32-36”
From Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections (2022) · cites this paper as [27]
In the citing paper
“Notwithstanding these limitations, consistent findings were reached, indicating rapid waning of vaccine protection against symptomatic Omicron infection that are consistent with findings of other studies for effectiveness against Omicron infection (with no BA.1/BA.2 subvariant specified)42–48.”
From Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (2022) · cites this paper as [42]
In the citing paper
“Similar to our results, a test-negative study from England determined that booster mRNA vaccination was associated with increased protection against symptomatic infection and severe COVID-19 with waning of protection observed 1 to 2 months following booster vaccination.5”
In the citing paper
“Population studies from the UK and Qatar have demonstrated that receipt of a third (booster) dose of mRNA COVID-19 vaccine increases protection against Omicron infection and severe disease.4,5”
In the citing paper
“Even a third booster shot may not adequately protect against Omicron infection 39,41”
From Striking antibody evasion manifested by the Omicron variant of SARS-CoV-2 (2022) · cites this paper as [39]
In the citing paper
“A recent study has concluded that two doses of either the Pfizer/BioNTech or the Oxford/AstraZeneca vaccine provide limited protection against symptomatic disease caused by Omicron, and a ‘booster’ dose with an mRNA vaccine would increase protection substantially, but only for a short period of time, falling between 39% and 45% after 2 months. 29”
From Vaccine mandates for healthcare workers beyond COVID-19 (2023) · cites this paper as [29]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Rated minor: it would not touch a result — a value no result rests on, a p-value that stays on the same side of the significance level, or a conflict that is clerical, resolved elsewhere in the paper, or outside its own findings.
In the paper
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Data Sources
“Beginning on January 10, 2022, delta cases were identified by sequencing and genotyping only because the positive predictive value of S target–negative status to identify the delta variant had decreased and could no longer be used.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Data Sources
“the omicron variant has been associated with S target–negative results on PCR testing with the TaqPath assay, whereas the delta variant almost always has an S target–positive result.”
Rated minor: it would not touch a result — a value no result rests on, a p-value that stays on the same side of the significance level, or a conflict that is clerical, resolved elsewhere in the paper, or outside its own findings.
In the paper
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Data Sources
“Testing data were linked to the NIMS on January 18, 2021, through combinations of the unique individual NHS number, date of birth, surname, first name, and postal code with the use of deterministic linkage.”
§ Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant > Methods > Data Sources
“The NIMS was accessed on January 18, 2022, for dates of vaccination and vaccine manufacturer, sex, date of birth, race or ethnic group, and residential address.”
Citations
Cites
Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine
Polack, F. P., Thomas, S. J., Kitchin, N., Absalon, J., Gurtman, A., Lockhart, S., Perez, J. L., Pérez Marc, G., Moreira, E. D., Zerbini, C., et al. (2020) · New England Journal of Medicine · doi:10.1056/nejmoa2034577 · Cited by 14,592
Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine
Baden, L. R., El Sahly, H. M., Essink, B., Kotloff, K., Frey, S., Novak, R., Diemert, D., Spector, S. A., Rouphael, N., Creech, C. B., et al. (2021) · New England Journal of Medicine · doi:10.1056/nejmoa2035389 · Cited by 10,119
Voysey, M., Clemens, S. A. C., Madhi, S. A., Weckx, L. Y., Folegatti, P. M., Aley, P. K., Angus, B., Baillie, V. L., Barnabas, S. L., Bhorat, Q. E., et al. (2021) · The Lancet · doi:10.1016/s0140-6736(20)32661-1 · Cited by 4,616
Khoury, D. S., Cromer, D., Reynaldi, A., Schlub, T. E., Wheatley, A. K., Juno, J. A., Subbarao, K., Kent, S. J., Triccas, J. A., & Davenport, M. P. (2021) · Nature Medicine · doi:10.1038/s41591-021-01377-8 · Cited by 3,742
Effectiveness of Covid-19 Vaccines against the B.1.617.2 (Delta) Variant
Lopez Bernal, J., Andrews, N., Gower, C., Gallagher, E., Simmons, R., Thelwall, S., Stowe, J., Tessier, E., Groves, N., Dabrera, G., et al. (2021) · New England Journal of Medicine · doi:10.1056/nejmoa2108891 · Cited by 2,889
Self-citationBNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting
Dagan, N., Barda, N., Kepten, E., Miron, O., Perchik, S., Katz, M. A., Hernán, M. A., Lipsitch, M., Reis, B., & Balicer, R. D. (2021) · New England Journal of Medicine · doi:10.1056/nejmoa2101765 · Cited by 2,527
Lopez Bernal, J., Andrews, N., Gower, C., Robertson, C., Stowe, J., Tessier, E., Simmons, R., Cottrell, S., Roberts, R., O’Doherty, M., et al. (2021) · BMJ · doi:10.1136/bmj.n1088 · Cited by 1,389
Self-citationCele, S., Jackson, L., Khoury, D. S., Khan, K., Moyo-Gwete, T., Tegally, H., San, J. E., Cromer, D., Scheepers, C., Amoako, D., et al. (2021) · doi:10.1101/2021.12.08.21267417 · Cited by 1,333
Protection of BNT162b2 Vaccine Booster against Covid-19 in Israel
Bar-On, Y. M., Goldberg, Y., Mandel, M., Bodenheimer, O., Freedman, L., Kalkstein, N., Mizrahi, B., Alroy-Preis, S., Ash, N., Milo, R., et al. (2021) · New England Journal of Medicine · doi:10.1056/nejmoa2114255 · Cited by 1,169
Waning Immunity after the BNT162b2 Vaccine in Israel
Goldberg, Y., Mandel, M., Bar-On, Y. M., Bodenheimer, O., Freedman, L., Haas, E. J., Milo, R., Alroy-Preis, S., Ash, N., & Huppert, A. (2021) · New England Journal of Medicine · doi:10.1056/nejmoa2114228 · Cited by 1,034
Cited by
Sorted by citations
Cele, S., Jackson, L., Khoury, D. S., Khan, K., Moyo-Gwete, T., Tegally, H., San, J. E., Cromer, D., Scheepers, C., Amoako, D., et al. (2021) · doi:10.1101/2021.12.08.21267417 · Cited by 1,333
Nyberg, T., Ferguson, N. M., Nash, S. G., Webster, H. H., Flaxman, S., Andrews, N., Hinsley, W., Bernal, J. L., Kall, M., Bhatt, S., et al. (2022) · The Lancet · doi:10.1016/s0140-6736(22)00462-7 · Cited by 1,221
Self-citationSARS-CoV-2 variant biology: immune escape, transmission and fitness
Carabelli, A. M., Peacock, T. P., Thorne, L., Harvey, W. T., Hughes, J., de Silva, T. I., Peacock, S. J., Barclay, W., de Silva, T. I., Towers, G. J., et al. (2023) · Nature Reviews Microbiology · doi:10.1038/s41579-022-00841-7 · Cited by 1,386
Striking antibody evasion manifested by the Omicron variant of SARS-CoV-2
Liu, L., Iketani, S., Guo, Y., Chan, J. F.-W., Wang, M., Liu, L., Luo, Y., Chu, H., Huang, Y., Nair, M. S., et al. (2022) · Nature · doi:10.1038/s41586-021-04388-0 · Cited by 1,290
Nyberg, T., Ferguson, N. M., Nash, S., Webster, H. H., Flaxman, S. R., Andrews, N. J., Hinsley, W. R., Bernal, J. L., Kall, M. M., Bhatt, S., et al. (2022) · Northumbria Research Link (Northumbria University) · doi:10.17863/cam.81883 · Cited by 1,129
Self-citation
Metadata
- Authors
- Andrews, N., Stowe, J., Kirsebom, F., Toffa, S., Rickeard, T., Gallagher, E., Gower, C., Kall, M., Groves, N., O’Connell, A.-M., Simons, D., Blomquist, P. B., Zaidi, A., Nash, S., Aziz, N. I. B. A., Thelwall, S., Dabrera, G., Myers, R., Amirthalingam, G., Gharbia, S., Barrett, J. C., Elson, R., Ladhani, S. N., Ferguson, N., Zambon, M., Campbell, C. N., Brown, K., Hopkins, S., Chand, M., Ramsay, M., & Bernal, J. L.
- Affiliations
- St George's, University of London (GB)
- Corresponding author
- Bernal, Jamie Lopez
- ORCID
- Venue
- New England Journal of Medicine
- Publisher
- openRxiv
- Published
- 2021-12-14
- Volume
- 386
- Issue
- 16
- Pages
- 1532-1546
- ISSN
- 0028-4793 (ISSN-L)
- PMC
- PMC8908811
- OpenAlex
- W4214863616
- Cited by
- 2,420
- References
- 24
- Citations by year
- 2026: 100 · 2025: 212 · 2024: 394 · 2023: 766 · 2022: 928 · 2021: 19
- FWCI
- 281.11
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- New England Journal of Medicine (publishedVersion)
- medRxiv (acceptedVersion, cc-by-nc-nd)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- St George's Online Research Archive (St George's University of London) (acceptedVersion)
- LSHTM Research Online (London School of Hygiene and Tropical Medicine) (acceptedVersion)
- UEA Digital Repository (University of East Anglia) (submittedVersion)
- Funders
- Wellcome Trust
- National Institute for Health and Care Research (NIHR201395)
- Medical Research Council (MR/R015600/1)
- Biotechnology and Biological Sciences Research Council (BB/M009513/1)
- Topics
- Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
- Social Sciences › Health › Vaccine Coverage and Hesitancy
- Physical Sciences › Mathematics › Modeling and Simulation › COVID-19 epidemiological studies
- Keywords
- COVID-19 vaccine effectiveness, Omicron variant, Delta variant, BNT162b2, ChAdOx1 nCoV-19 vaccine, mRNA-1273, booster vaccination, waning vaccine effectiveness, symptomatic infection, test-negative case-control design
- MeSH terms
- COVID-19, SARS-CoV-2, COVID-19 Vaccines, Vaccine Efficacy, BNT162 Vaccine, 2019-nCoV Vaccine mRNA-1273, ChAdOx1 nCoV-19, Humans, Immunization, Secondary, Case-Control Studies
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-10, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-10 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Cited sources are checked with a language model’s help (gpt-6-sol).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
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