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There has been some evidence of person-to-person transmission during the pre-symptomatic phase. Other coronaviruses (as noted above) have not displayed transmissibility via blood or hematopoietic progenitor cells (HPC), which suggests that the blood phase of this group of viruses coronavirus RNA is limited to the symptomatic phase. Even if this virus is not an infective risk for HPC, however, the quarantine/isolation requirements for at-risk people will likely make affected HPC donors unavailable for at least 14 days – the commonly accepted upper limit for COVID-19 incubation.
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