Vaccine development for SARS-CoV-2 is looking very challenging. The problem is that the antibodies that the body naturally produces against SARS-CoV-2 have a pretty high chance of triggering worse effects in the body than the virus itself does. Those are your own, natural antibodies; they can kill you by triggering cytokine storm. It seems that SARS-CoV-2 is a bloody clever virus.
The problem for vaccine development is that vaccines work by inducing the immune system to produce antibodies against the virus, but if such antibodies can kill you anyway, then the vaccine could too.