Nanoparticle vaccines are extremely promising on this front. In animal tests they are blocking multiple coronaviruses. Basically, they form a cage and you can add protein sequences to the cage. It's like showing the immune system a gallery instead of one photo.

They are about to start human clinical trials of this vaccine.

And the really good news is that if this does work, they should be able to do the same trick on influenza, giving us the long term holy grail of a lineage-proof influenza vaccine that may not have to be repeated every year.