I think trials for this are beginning - I suspect it would have been a hard thing to include in the WHO trial, as a hospital needs to be fairly sophisticated to be able to coordinate plasma retrieval and cleaning locally (vs buying RBCs from a local supplier).

I’m curious /excited to rare how this dynamic changes once we get serological tests online. Maybe all of the mild cases amongst youth can give enough serum to treat the harder hit individuals.

Here’s a recent discussion about serum:

https://www.globalhealthnow.org/2020-03/covid-19s-stop-gap-s...

And the linked study:

https://www.jci.org/articles/view/138003