It does indeed look like good news, but it is important to recognize the limitations of what was found.
recoverytrial.net/files/recovery…

Presumably it works by suppressing the overactive immune response in these patients.
The NNT tells you how many people you need to treat to have a beneficial outcome in 1 person.
For patients on ventilators, you need to treat 8 to prevent one death.
For patients on oxygen, 25 to prevent one death.
(figure from bbc.com/news/health-53…)

Would I take it? Sure.
It is a miracle drug? No.
It's great that we are starting to learn how to better care for patients suffering respiratory difficulty from COVID.
That should save many lives.
Nor, if you have COVID, will it prevent you from being hospitalized.
Nor, if you are hospitalized, is it guaranteed to save your life.
It's an incremental step, not a panacea.
Study: Dexamethasone is useful for patients with non-severe, very bad disease who need supplemental O2.
