Covid-19 Rates by Time since Vaccination during Delta Variant Predominance.

ABSTRACT:

Background

With the emergence of the delta variant, the United States experienced a rapid increase in Covid-19 cases in 2021. We estimated the risk of breakthrough infection and death by month of vaccination as a proxy for waning immunity during a period of delta variant predominance.

Methods

Covid-19 case and death data from 15 U.S. jurisdictions during January 3 to September 4, 2021 were used to estimate weekly hazard rates among fully vaccinated persons, stratified by age group and vaccine product. Case and death rates during August 1 to September 4, 2021 were presented across four cohorts defined by month of vaccination. Poisson models were used to estimate adjusted rate ratios comparing the earlier cohorts to July rates.

Results

During August 1 to September 4, 20

SUBMITTER: Paz-Bailey G 

PROVIDER: S-EPMC10193243 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature