So I am not sure anyone can say anything for sure. What we know is this infection creates an aggressive immune response and the immune system's attack on the lungs will actually cause damage to the lung tissue if not controlled.
I can tell you this much, as much quackery is on the internet about Vitamin C, it is accepted as a necessary means of clearing neutrophils from infections and thus reducing necrosis. It is also known to help maintain epithelial barrier function. It can also improve T-cell differentiation, which I hypothesize is very important in avoiding damage from a hypeactive immune response.
Vitamin C is an essential micronutrient for humans, with pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune ...
www.ncbi.nlm.nih.gov
Because Vitamin C doesn't stick around for very long normally and gets used up at higher rates during infection, it makes sense that it would be easy to be vitamin C repeated during any infection, and this would lead to impaired immunity, and an impaired ability to remove toxic byproducts from the site of infection.
So, will vitamin C cure this it prevent it? I wouldn't go that far. But could it be very helpful to have onboard when fighting a serious infection? I truly believe so. Even the most sited study saying it does not work showed a dramatic reduction in the severity and duration of colds in highly stressed individuals.
It seems to me like, maintaining healthy epithelial functions, building collagen, etc. MAY help prevent it to some small extent (not a vaccine) - but once you have it, reduction of severity and duration could be just enough to save your life even if it is by 5%.
Or I could just be a vitamin C quack.