It is an anti-parasitic and immune-regulation drug. Not really an antiviral. I guess the theory is that it’d regulate an immune over-response. But I don’t think the science is m showing that to be true in this case.
https://www.ncbi.nlm.nih.gov/pubmed/8546725
https://www.sciencedirect.com/science/article/abs/pii/S10434...