From the study:


CRP is sent by your liver into the bloodstream as a response to inflammation. So a decrease in CRP and decrease in WHO clinical severity scores suggests the UVA treatment is indeed having a multisystem effect.

Also, reducing viral load in the lungs (suggested by reduction in viral aspirate) should free up the lungs to do a better job of oxygenating blood, thus possibly avoiding or reducing the need for invasive treatments like ventilators and ECMO.