Delta variants of SARS-CoV-2 cause significant higher vaccine breakthrough COVID cases in Houston, Texas

 James M. Musser, Paul A. Christensen, Randall J. Olsen,  

View ORCID ProfileScott Wesley Long, Sishir Subedi, James J. Davis, Parsa Hodjat, Debbie R. Walley, Jacob C. Kinskey, Jimmy D. Gollihar

doi: https://doi.org/10.1101/2021.07.19.21260808

This article is a preprint and has not been certified by peer review [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

PDF: https://www.medrxiv.org/content/10.1101/2021.07.19.21260808v1.full.pdf

Abstract

Genetic variants of SARS-CoV-2 have repeatedly altered the course of the COVID-19 pandemic, and disease in individual patients. Delta variants (B.1.617.2, AY.2, and AY.3) are now the focus of international concern because they are causing widespread COVID-19 disease globally. Vaccine breakthrough cases caused by SARS-CoV-2 variants also are of considerable public health and medical concern worldwide. As part of a comprehensive project, we sequenced the genomes of 3,913 SARS-CoV-2 from patient samples acquired March 15, 2021 through July 3, 2021 in the Houston Methodist hospital system and studied vaccine breakthrough cases. During the study period Delta variants increased to cause 58% of all COVID-19 cases and spread throughout the metropolitan Houston area. In addition, Delta variants caused a significantly higher rate of vaccine breakthrough cases (19.7% compared to 5.8% for all other variants). Importantly, only 6.5% of all COVID-19 cases occurred in fully immunized individuals, and relatively few of these patients required hospitalization. Our genomic and epidemiologic data emphasize that vaccines used in the United States are highly effective in decreasing severe COVID-19 disease, hospitalizations, and deaths.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

The research was supported by the Houston Methodist Academic Institute Infectious Diseases Fund and many generous Houston philanthropists. James Davis was funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contract No. 75N93019C00076.

https://www.medrxiv.org/content/10.1101/2021.07.19.21260808v1