SARS-Associated Coronavirus Quasispecies in Individual Patients

Abstract
Quasispecies are known in RNA viruses such as hepatitis C virus and human immunodeficiency virus.1 Owing to poor fidelity of RNA polymerases, RNA-virus populations typically contain genetic variants that form a heterogeneous virus pool. The severe acute respiratory syndrome (SARS)–associated coronavirus, as a newly identified RNA virus,2 however, has been reported with relatively limited variations,3,4 and no published data have recorded the existence of quasispecies.