There are many studies in which glutathione has been shown to have a positive effect on many other viral diseases and plays an important role in the development of these infections. Most viruses studied thrive in a low glutathione environment and high oxidative stress.
A recent study (see below) from China shows that moderate to severe Covid-19 patients are not able to make CD4+T and CD8+ T cells. These are the killer cells a persons immune system uses to kill viral and bacterial infections. This is why Glutathione is so critical. It allows the body to make CD4+T and CD8+ T cells to any level needed as long as you fuel Glutathione production.