Gottlieb M, Wang R, Yu H, Spatz ES, et al. Severe Fatigue and Persistent Symptoms at Three Months Following SARS-CoV-2
Infections During the Pre-Delta, Delta, and Omicron Time Periods: A Multicenter
Prospective Cohort Study. Clin Infect Dis 2023 Jan 27:ciad045. doi: 10.1093.
PMID: 36705268