Abstract
Background SARS-CoV-2 (COVID-19) has caused over 80 million infections and 973,000 deaths in the United States, and mutations are linked to increased transmissibility. This study aimed to determine the effect of SARS-CoV-2 variants on respiratory features and mortality and to determine the effect of vaccination status.
Method A retrospective review of medical records (n=63,454 unique patients) using The University of California Health COvid Research Data Set (UC CORDS) was performed to identify respiratory features, vaccination status, and mortality. Variants were identified using the CDC data tracker.
Results Increased odds of death were observed among those not fully vaccinated (Delta OR: 1.64, p = 0.052; Omicron OR: 1.96, p < 0.01). Later variants (i.e., Delta and Omicron) demonstrated a reduction in the frequency of lower respiratory tract features with a concomitant increase in upper respiratory tract features. Vaccination status was associated with survival and a decrease in the frequency of many upper and lower respiratory tract features.
Discussion SARS-CoV-2 variants show a reduction in lower respiratory tract features with an increase in upper respiratory tract features. Being fully vaccinated results in fewer respiratory features and higher odds of survival, supporting vaccination in preventing morbidity and mortality from COVID-19.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
This study did not receive any funding
Author Declarations
I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.
Yes
The details of the IRB/oversight body that provided approval or exemption for the research described are given below:
This study was deemed exempted from obtaining ethical approval by the University of California, internal review board. All methods were carried out in accordance with relevant university guidelines and regulations. The UC CORDS dataset contains de-identified data from individuals seeking care in the University of California Health System, as such the Institutional Review Board at the University of California-Irvine, waived the need for obtaining informed consent. No experimental protocols were used in this study of de-identified data; therefore, no approvals were sought from the University.
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Yes
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Footnotes
On page 22, the figure titled ‘Frequency of most common lower respiratory features in covid positive patients" was erroneously titled "Frequency of most common neurological features in covid positive patients.’ Within the body of the manuscript the figure was correct; however, the incorrect .jpg file was attached as a separate upload.
Data Availability
The dataset used in this study, University of California Covid Research Data Set (UC CORDS), is made available by the University of California Office of the President and the University of California Biomedical, Research, Acceleration, Integration, and Development. The datasets analyzed during this study are not publicly available. Questions regarding the UC CORDS Data Set can be directed to the project contact, Atul Butte (atul.butte@ucsf.edu).
https://covidresearch.ucsf.edu/projects/uc-health-covid-research-data-set-uc-cords