mRNA-1273 COVID-19 vaccine effectiveness against the B.1.1.7 and B.1.351 variants and severe COVID-19 disease in Qatar
Open accessAbstract
The SARS-CoV-2 pandemic continues to be a global health concern. The mRNA-1273 (Moderna) vaccine was reported to have an efficacy of 94.1% at preventing symptomatic COVID-19 due to infection with 'wild-type' variants in a randomized clinical trial. Here, we assess the real-world effectiveness of this vaccine against SARS-CoV-2 variants of concern, specifically B.1.1.7 (Alpha) and B.1.351 (Beta), in Qatar, a population that comprises mainly working-age adults, using a matched test-negative, case-control study design. We show that vaccine effectiveness was negligible for 2 weeks after the first dose, but increased rapidly in the third and fourth weeks immediately before administration of a second dose. Effectiveness against B.1.1.7 infection was 88.1% (95% confidence interval (CI): 83.7-91.5%) ≥14 days after the first dose but before the second dose, and was 100% (95% CI: 91.8-100.0%) ≥14 days after the second dose. Analogous effectiveness against B.1.351 infection was 61.3% after the first dose (95% CI: 56.5-65.5%) and 96.4% after the second dose (95% CI: 91.9-98.7%). Effectiveness against any severe, critical or fatal COVID-19 disease due to any SARS-CoV-2 infection (predominantly B.1.1.7 and B.1.351) was 81.6% (95% CI: 71.0-88.8%) and 95.7% (95% CI: 73.4-99.9%) after the first and second dose, respectively. The mRNA-1273 vaccine is highly effective against B.1.1.7 and B.1.351 infections, whether symptomatic or asymptomatic, and against any COVID-19 hospitalization and death, even after a single dose.
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Real-world studies performed a few months into COVID-19 vaccination campaigns showed high effectiveness of these vaccines.
“Real-world setting studies performed, few months into vaccination campaigns, showed high effectiveness of these vaccines [1-8].”
Several studies have described a drop over time of two-dose vaccine effectiveness against SARS-CoV-2 symptomatic infection.
“Several studies have described a drop over time of two-dose vaccine effectiveness against SARS-CoV-2 symptomatic infection;”
From Vaccine effectiveness and duration of protection of COVID-19 mRNA vaccines against Delta and Omicron BA.1 symptomatic and severe COVID-19 outcomes in adults aged 50 years and over in France (2023) · cites this paper as [3]
The vaccine-effectiveness results report high effectiveness shortly after the second dose, and the Discussion describes protection increasing as the dose schedule progressed. Our copy does not report whether effectiveness against symptomatic infection declined over time after two doses (searched for waning, decline, and long-term follow-up). Pages were not provided for these passages. (LLM, conf=0.75)
Experimental — accuracy not yet measuredThe decrease in protection was substantially higher against Omicron BA.1 compared to Delta.
“this decrease in protection was substantially higher against Omicron BA.1 compared to Delta [3,8,12,19,26].”
From Vaccine effectiveness and duration of protection of COVID-19 mRNA vaccines against Delta and Omicron BA.1 symptomatic and severe COVID-19 outcomes in adults aged 50 years and over in France (2023) · cites this paper as [3]
The Discussion and Additional analyses sections report mRNA-1273 effectiveness against B.1.1.7 and B.1.351, not a decrease in protection against Omicron BA.1 versus Delta. Searches for Omicron BA.1 and Delta found no passage in our copy addressing that comparison; page numbers were not available. (LLM, conf=0.78)
Experimental — accuracy not yet measuredMatching on sex, age, nationality, and calendar week was previously shown to adequately control for differences in SARS-CoV-2 exposure risk in Qatar.
“Matching according to these factors was previously shown to provide adequate control of differences in the risk of SARS-CoV-2 exposure in studies of different designs, all of which involved control groups, such as test-negative, case–control studies.”
From Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections (2022) · cites this paper as [15]
Matching was not possible for coexisting conditions, but matching on sex, age, and nationality provided demonstrable control of bias in earlier studies.
“Although matching was performed according to sex, age, and nationality, matching was not possible for other factors, such as coexisting conditions. However, matching according to these factors provided demonstrable control of bias in our earlier studies.11,12,15,21,22”
From Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections (2022) · cites this paper as [15]
Effectiveness was assessed with a test-negative case-control design rather than a cohort design, but an earlier cohort study in the same population yielded similar findings.
“Effectiveness was assessed with the use of an observational, test-negative, case–control design rather than a design in which cohorts of individual persons were followed up. However, the cohort study design applied earlier to the same population yielded findings similar to those of the test-negative design.14,15,31”
From Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections (2022) · cites this paper as [15]
Matching by sex, age, and nationality provided demonstrable control of bias in studies of different epidemiologic designs that used control groups in Qatar.
“However, matching by these factors provided demonstrable control of bias in studies of different epidemiologic designs and that used control groups in Qatar13,14,35–37.”
From Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (2022) · cites this paper as [36]
The cohort study design applied earlier to the same population of Qatar yielded findings similar to those of the test-negative case-control design, supporting the validity of this standard approach in assessing vaccine effectiveness.
“However, the cohort study design applied earlier to the same population of Qatar yielded findings similar to those of the test-negative case–control design36,38,39, supporting the validity of this standard approach in assessing vaccine effectiveness11,12,36,40.”
From Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (2022) · cites this paper as [36]
Vaccine effectiveness against symptomatic SARS-CoV-2 Omicron infection during the Omicron wave in Qatar was estimated using the test-negative, case-control study design, a standard design for assessing vaccine effectiveness.
“Vaccine effectiveness against symptomatic SARS-CoV-2 Omicron (B.1.1.529)1 infection during the large Omicron wave in Qatar, between December 23, 2021 and February 28, 2022, was estimated using the test-negative, case–control study design, a standard design for assessing vaccine effectiveness11,12,36,40.”
From Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar (2022) · cites this paper as [36]
Real-world data showed mRNA-1273 effectiveness against Alpha was 100%, against Beta 96.4%, and against Delta 73.1%.
“Real-world data showed that effectiveness of mRNA-1273 against Alpha and Beta variants was 100% and 96.4%, respectively,417,418 whereas effectiveness against Delta was slightly lower (73.1%).102”
From Advances in COVID-19 mRNA vaccine development (2022) · cites this paper as [417]
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References 29 · Cited by 386
Research works printed but not linked: 16
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- Authors
- Chemaitelly, H., Yassine, H. M., Benslimane, F. M., Al Khatib, H. A., Tang, P., Hasan, M. R., Malek, J. A., Coyle, P., Ayoub, H. H., Al Kanaani, Z., Al Kuwari, E., Jeremijenko, A., Kaleeckal, A. H., Latif, A. N., Shaik, R. M., Abdul Rahim, H. F., Nasrallah, G. K., Al Kuwari, M. G., Al Romaihi, H. E., Al-Thani, M. H., Al Khal, A., Butt, A. A., Bertollini, R., & Abu-Raddad, L. J.
- Affiliations
- Cornell University (US)
- Qatar University (QA)
- Sidra Medical and Research Center (QA)
- Queen's University Belfast (GB)
- Hamad Medical Corporation (QA)
- Ministry of Public Health (QA)
- Corresponding author
- Abu-Raddad, Laith J.
- ORCID
- Venue
- Nature Medicine
- Published
- 2021-07-09
- Volume
- 27
- Issue
- 9
- Pages
- 1614-1621
- ISSN
- 1078-8956 (ISSN-L)
- 1546-170X
- OpenAlex
- W3177903130
- Cited by
- 386
- References
- 29
- Citations by year
- 2026: 11 · 2025: 26 · 2024: 34 · 2023: 68 · 2022: 174 · 2021: 73
- FWCI
- 27.63
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Nature Medicine (publishedVersion)
- PubMed (publishedVersion)
- Research Portal (Queen's University Belfast) (publishedVersion, other-oa)
- LSHTM Research Online (London School of Hygiene and Tropical Medicine) (acceptedVersion)
- Qatar University QSpace (Qatar University) (submittedVersion)
- Funders
- Hamad Medical Corporation
- Weill Cornell Medical College
- Weill Cornell Medicine - Qatar
- Topics
- Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
- Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
- Social Sciences › Health › Vaccine Coverage and Hesitancy
- Keywords
- mRNA-1273 vaccine, COVID-19 vaccine effectiveness, SARS-CoV-2 variants of concern, B.1.1.7 Alpha variant, severe COVID-19, real-world effectiveness, test-negative case-control, Qatar
- MeSH terms
- COVID-19, SARS-CoV-2, COVID-19 Vaccines, 2019-nCoV Vaccine mRNA-1273, Breakthrough Infections, Adult, Aged, Aged, 80 and over, Antibodies, Viral, Female, Humans, Male, Middle Aged, Qatar, Case-Control Studies, Genome, Viral, Young Adult
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