Study registration: *
Publication Lin D, medRxiv, 2021
Dates: 2020-12-13 to 2021-09-08
Funding: Public/non profit (NIAID)
Conflict of interest: no COI (The authors have declared no competing interest.)

Methods

Study design:Cohort
Description of participants: Residents of North Carolina, USA
Inclusion criteria:
  • Individuals vaccinated in North Carolina by a North Carolina state provider or federal pharmacy provider during the period from December 13, 2020 through September 8, 2021

Exclusion criteria:
  • *

Follow-up duration (months): 8.87
Vaccines:
  • 1 or 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

NR

Data-sharing stated: Yes
Data accessibility: All data produced in the present study are available upon reasonable request to the North Carolina Department of Public Health
General comment The main concern is with uncontrolled confounding. The results extracted only controlled for calendar time (although were similar to results adjusting for age, sex, race/ethnicity, geographical region, and county-level vaccination rate).
As the exact date of the second dose of vaccine is not reported (Table 2 starts counting events after the first dose), the vaccine effectiveness (VE) for the time interval of 1-2 months was selected to reflect VE after full vaccination.