Study registration: *
Publication Cohn B, medRxiv, 2021
Dates: 2020-12-31 to 2021-07-31
Funding: Public/non profit (Mercatus Center at George Mason University and University of California Office of the President.)
Conflict of interest: Yes (CCM reports consulting for Freenome. AWW reports consulting for ECOM Medical, Obelab, Sensifree, and Shifamed. BAC, PMC, and NYK declare that they have no competing interests.)

Methods

Study design:Cohort
Description of participants: Adults aged 18 and older including elderly and co-morbidities in all states and territories of USA
Inclusion criteria:
  • U.S. Veterans
  • aged 18 and older
  • in all states and territories of USA
  • receiving care in the Veterans Health Administration (VHA)
  • tested in July 2021.

Exclusion criteria:
  • Partial vaccinations
  • vaccinations administered off-label and/or not according to recommendation.

Follow-up duration (months): 7.00
Vaccines:
  • 2 doses of mRNA-1273
  • 2 doses of BNT162b2
  • 1 dose of Ad26.COV2.S
Variant description :
Variant name: Delta
Evidence: Indirect evidence (prevalence of variant in the population: 1 to 99%)
Documents
available

Protocol

NR

Statistical plan

No

Data-sharing stated: Yes
Data accessibility: The data that support the findings of this study are available from the Department of Veterans Affairs (VA). Data are made freely available to researchers behind the VA firewall with an approved study protocol. More information is available at https://www.virec.research.va.gov or by contacting the VA Information Resource Center at VIReC{at}va.gov.
General comment The preprint was used in data extraction and risk of bias assessment. Infection results are presented for the subgroup tested in July 2021.
Concerns over uncontrolled confounding and potential for selection bias due to restriction of the analysis sample to those who received a PCR test during the vaccinated or unvaccinated follow up time.