A vaccine to this point has never been successfully developed for any Coronavirus
Yes. Previous CV vaccine research ran into problems. Far from being protective, vaccinated animals did worse when subsequently exposed to the virus. In the end, SARS disappeared and CV vaccine research was shelved with some warnings for future potential researchers.
A vaccine is possible. Sure. A lot of $ are being thrown at this. But it remains highly speculative. As do any plans dependent on a vaccine.