Affiliation:
1. Division of Population and Preventive Health, Department of Obstetrics & Gynecology The University of Texas Medical Branch at Galveston Galveston Texas USA
2. Center for Interdisciplinary Research in Women's Health, School of Medicine The University of Texas Medical Branch at Galveston Galveston Texas USA
3. Office of Biostatistics, School of Public and Population Health The University of Texas Medical Branch at Galveston Galveston Texas USA
Abstract
AbstractStudies have suggested the effectiveness of COVID‐19 vaccines in preventing SARS‐CoV‐2 reinfection among those previously infected. However, it is not yet clear if one dose of the vaccine is enough to prevent breakthrough infections compared to two doses. Using data from Optum deidentified COVID‐19 Electronic Health Record (EHR) data set, we assessed breakthrough infection risks in individuals previously infected, comparing those with one vaccine dose to those with two doses. Propensity scores were applied to mitigate confounding factors. Follow‐up spanned 6 months, beginning 2 weeks postvaccination. Among 213 845 individuals, those receiving one vaccine dose had a significantly higher breakthrough infection risk than the two‐dose group (HR 1.69, 95% CI 1.54–1.85). This pattern was observed across genders, racial/ethnic groups, age categories, and vaccine types. This study reveals a substantial disparity in the risk of breakthrough infections between individuals receiving one versus two doses of the COVID‐19 vaccine, suggesting that a single dose may not provide adequate protection against reinfection.
Subject
Infectious Diseases,Virology