Why has there not been a vaccine developed for SARS-Cov-1?
Are there any long term effects of contracting ebola? (for people who recover)
Can dead people spread SARS-Cov-2?
There were some vaccines under development for SARS-CoV-1 but SARS pretty much burned itself out before a vaccine was required. So the research stopped.
I am not sure of long-term effects from Ebola; I would have to look this up.
Because SARS-CoV-2 is a respiratory virus, probably not transmissible from a cadaver.