There is a concept of viral load.
Viral load has been considered in connection with HIV (Impact of viral load and the duration of primary infection on HIV transmission: systematic review and meta-analysis, 2014, Blaser et al.).
In another context, a 2010 article by several authors, DeVincenzo et al, Viral Load Drives Disease in Humans Experimentally Infected with Respiratory Syncytial Virus. Page 1312 of the report mentions “the potential clinical effectiveness derived by achieving a robust reduction in viral load through antiviral compounds."
Is it possible that how much virus there is affects how serious a disease results on being infected by COVID-19? If that were so, then in addition to isolating COVID-19 cases to inhibit transmission, it might be possible to inhibit severity of the disease by reducing viral load.
Is there research on this? If not, should there be?