This is highly technical. But if you are interested, here is a paper from the American Association for the Advancement of Science just published on research to find a vaccine. The paper describes various viral proteins that could serve as targets of a vaccine.
These proteins have 3D structures that facilitate attachment of the virus to human cells. The 3D structures change as the virus attaches. Understanding these structures will be key to developing an effective vaccine.
The laboratory work necessary for this type of research is pretty amazing. Early in my career I worked for a few years as a lab technician in the Biochemistry Department at the University of Rochester and did some of the steps described in this paper such as running affinity and size exclusion chromatography. But that was many years ago. I am by no means an expert.