Study registration: *
Publication Grannis S, MMWR, 2021
Dates: 2021-01-01 to 2021-08-04
Funding: Mixed (VISION network is funded by CDC and includes Columbia University Irving Medical Center (New York), HealthPartners (Minnesota and Wisconsin), Intermountain Healthcare (Utah), Kaiser Permanente Northern California (California), Kaiser Permanente Northwest (Oregon and Washington), Regenstrief Institute (Indiana), and University of Colorado (Colorado).)
Conflict of interest: NR

Methods

Study design:Test-negative
Description of participants: Adults hospitalized with COVID-19-like illness in 9 states in multiple centres in USA
Inclusion criteria:
  • Adults aged ≥18 years
  • had received SARS-CoV-2 molecular testing (primarily reverse transcription–polymerase chain reaction assay within 14 days before or 72 hours after the admission or encounter)
  • COVID-19–like illness discharge diagnosis
  • hospitalized in the following states (during these time periods in 2021): Indiana (July 3–26), Oregon and Washington (June 30–August 4), Utah (June 1–July 24), California (June 23–August 4), Colorado (June 3–July 20), Minnesota and Wisconsin (July 1–August 2), and New York (June 30–July 25)

Exclusion criteria:
  • Partially vaccinated (received 1 mRNA dose only or had received the second dose <14 days before testing or encounter date
  • or <14 days after dose of Janssen vaccine)

Follow-up duration (months): 7.17
Vaccines:
  • 2 doses of mRNA-1273
  • 2 doses of BNT162b2
  • 1 dose of Ad26.COV2.S
  • 2 doses of BNT162b2 or mRNA-1273 or 1 dose of Ad26.COV2.S
Variant description :
Variant name: Delta
Evidence: Indirect evidence (prevalence of variant in the population: >50%)
Documents
available

Protocol

NR

Statistical plan

NR

Data-sharing stated: NR
Data accessibility: Corresponding author: Mark G. Thompson, isq8@cdc.gov
General comment The published report was used in data extraction and risk of bias assessment.
Some concerns over the possibility of uncontrolled confounding given the observational nature of the data, on outcome ascertainement being influenced by knowledge of vaccination status and on pre-specified plan not being available.