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.)
Description of participants: Residents of North Carolina, USA
Follow-up duration (months): 8.87
|Variant description :
Variant name: Delta|
Evidence: Indirect evidence (prevalence of variant in the population: 1 to 99%)
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.