[raducu]

It would be so nice if those people could have access to a coctail of synthetic antibodies that gave some protection to covid-19, the flu and others. Or perhaps a generic antibody that protects against most viruses(unlikely, given such an atibody does not exist in nature).

[duskwuff]

Antibodies don't themselves help fight infections; their role is simply to identify dangerous pathogens to white blood cells. In immunosuppressed patients, those cells often aren't present (or aren't responding properly), so adding antibodies wouldn't help.

[projektfu]

Antibodies also initiate the complement cascade and can thus kill cells directly.