Study registration: *
Publication Pilishvili T, NEJM, 2021
Dates: 2020-12-14 to 2021-05-19
Funding: Public/non profit (Centers for Disease Control and Prevention )
Conflict of interest: no COI (First and last authors disclosure forms: Are there other relationships or activities that readers could perceive to have influenced, or that give the appearance of potentially influencing, what you wrote in the submitted work? No. In the large writing group only a handful of authors (not first or last authors) had any conflicts to disclose.)

Methods

Study design:Test-negative
Description of participants: Health care personnel without previous SARS-CoV-2 infection at 33 centers in USA.
Inclusion criteria:
  • Cases: health care personnel
  • positive result for SARS-CoV-2 on polymerase-chain-reaction (PCR) testing, other nucleic acid amplification testing, or antigen-based testing
  • at least one of the following symptoms present within 14 days before or after the index test date: fever (a body temperature documented at ≥38°C or subjective fever), chills, cough (dry or productive), shortness of breath, chest pain or tightness, fatigue or malaise, sore throat, headache, runny nose, congestion, muscle aches, nausea or vomiting, diarrhea, abdominal pain, altered sense of smell or taste, loss of appetite, or red or bruised toes or feet. Controls: negative on PCR or other laboratory-based nucleic acid amplification testing, regardless of symptoms

Exclusion criteria:
  • Previous infection, defined as a positive SARS-CoV-2 test (on PCR or antigen testing) that had occurred more than 60 days before the index test date.

Follow-up duration (months): 5.20
Vaccines:
  • 1 or 2 doses of mRNA-1273
  • 1 or 2 doses of BNT162b2
Variant description :
Variant name: Alpha
Evidence: Indirect evidence (prevalence of variant in the population: 1 to 70%)
Documents
available

Protocol

Yes. In English

Statistical plan

Yes

Data-sharing stated: NR
Data accessibility: Dr. Pilishvili at tdp4@cdc.gov.
General comment Some concerns over uncontrolled confounding; in addition there are uncertainties over the possibility of selection bias in a test-negative design.