Study registration: *
Publication Polinski J, medRxiv, 2021
Dates: 2021-03-01 to 2021-07-31
Funding: Private (Janssen R&D)
Conflict of interest: Yes (Dr. Polinski, Mr. Weckstein, Dr. Batech, Ms. Kabelac and Dr. Rassen are employees of and own stock options or equity in Aetion, a software-enabled healthcare analytics company. Dr. Kamath, Mr. Harvey, Mr. Jain and Dr. Khan are employees of Janssen R&D, the manufacturer of the studied vaccine Ad26.COV2.S. Dr. Schneeweiss (ORCID# 0000-0003-2575-467X) is participating in investigator-initiated grants to the Brigham and Women’s Hospital from Boehringer Ingelheim unrelated to the topic of this study. He is a consultant to Aetion Inc. of which he owns equity. His interests were declared, reviewed, and approved by the Brigham and Women’s Hospital in accordance with their institutional compliance policies.)
Description of participants: Adults including elderly and co-morbidities with no history of COVID-19 in multiple centres throughout the USA
Follow-up duration (months): 5.00
|Variant description :
Variant name: Delta|
Evidence: Indirect evidence (prevalence of variant in the population: 83%)
In addition to the preprint, the supplementary material files were used in data extraction and risk of bias assessment. Results were extracted for the matched "high Delta incidence states" subgroup (assessed during June-July 2021) since the matched national cohort included periods of low Delta variant. Results were extracted that included a correction for vaccination under-reporting in claims databases; additionally, the authors reported that overall if, "assume 0% under-recording and completely disregard the necessary correction, the VE estimates would decline by about 10 percentage points". Authors used matching to account for confounding, with both risk-set sampling and propensity scores. Prevalence of Delta variant was not reported; stated that it became the dominant strain in overall USA by July 2021.
Concerns about uncontrolled confounding (e.g. by socioeconomic factors, ethnicity) and there is a strong indication that many vaccinations were not represented in the data set.