Study registration: *
Publication Thompson M, N Engl J Med, 2021
Dates: 2020-12-18 to 2021-06-22
Funding: Public/non profit (the Centers for Disease Control and Prevention)
Conflict of interest: Yes (Nicola Klein, grant/contract from GlaxoSmithKline, Merck, Pfizer, Protein Science, Sanofi Pasteur; Jill Ferdinands, travel assistance from Sanofi Pasteur; Allison Naleway, grant/contract from Pfizer; Suchitra Rao, grant/contract from BioFire Diagnostics, GlaxoSmithKline.)
Description of participants: Adults ≥50 years with Covid-19–like illness at multiple sites in the USA
Follow-up duration (months): 6.20
|Variant description :
Variant name: Alpha|
Evidence: Indirect evidence (prevalence of variant in the population: 16-81%)
Yes. In English
In addition to the published report, the protocol and supplementary material were used in data extraction and risk of bias assessment. The average prevalence of variants was not reported; among variants of concern, Alpha comprised the largest subset during the study period across the regions sampled.
Some concerns over the possibility of uncontrolled confounding given the observational nature of the data and of outcome ascertainment being influenced by knowledge of vaccination status.