Protection From COVID-19 mRNA Vaccination and Prior SARS-CoV-2 Infection Against COVID-19-Associated Encounters in Adults During Delta and Omicron Predominance.
J Infect Dis
; 227(12): 1348-1363, 2023 06 15.
Article
in English
| MEDLINE | ID: covidwho-2252865
ABSTRACT
BACKGROUND:
Data assessing protection conferred from COVID-19 mRNA vaccination and/or prior SARS-CoV-2 infection during Delta and Omicron predominance periods in the United States are limited.METHODS:
This cohort study included persons ≥18 years who had ≥1 health care encounter across 4 health systems and had been tested for SARS-CoV-2 before 26 August 2021. COVID-19 mRNA vaccination and prior SARS-CoV-2 infection defined the exposure. Cox regression estimated hazard ratios (HRs) for the Delta and Omicron periods; protection was calculated as (1-HR)×100%.RESULTS:
Compared to unvaccinated and previously uninfected persons, during Delta predominance, protection against COVID-19-associated hospitalizations was high for those 2- or 3-dose vaccinated and previously infected, 3-dose vaccinated alone, and prior infection alone (range, 91%-97%, with overlapping 95% confidence intervals [CIs]); during Omicron predominance, estimates were lower (range, 77%-90%). Protection against COVID-19-associated emergency department/urgent care (ED/UC) encounters during Delta predominance was high for those exposure groups (range, 86%-93%); during Omicron predominance, protection remained high for those 3-dose vaccinated with or without a prior infection (76%; 95% CI = 67%-83% and 71%; 95% CI = 67%-73%, respectively).CONCLUSIONS:
COVID-19 mRNA vaccination and/or prior SARS-CoV-2 infection provided protection against COVID-19-associated hospitalizations and ED/UC encounters regardless of variant. Staying up-to-date with COVID-19 vaccination still provides protection against severe COVID-19 disease, regardless of prior infection.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19
Type of study:
Cohort study
/
Experimental Studies
/
Observational study
/
Prognostic study
/
Randomized controlled trials
Topics:
Vaccines
/
Variants
Limits:
Adult
/
Humans
Language:
English
Journal:
J Infect Dis
Year:
2023
Document Type:
Article
Affiliation country:
Infdis
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