Provided is a method of enhancing an antigen-induced long-lasting immune response in a host comprising administering to a host an effective amount of: (a) a nonpathogenic recombinant rabies virus comprising at least three copies of a mutated G gene, wherein said mutated G gene encodes a rabies virus glycoprotein wherein the glycoprotein amino acid 194 is serine and the glycoprotein amino acid 333 is glutamic acid, wherein said recombinant rabies virus does not express a foreign protein antigen; and (b) a Coronavirus antigen that is not expressed by the rabies virus. Also provided are related compositions, kits and vaccines.

The present application relates to compositions and methods for tracing cell networks, e.g., for investigation of cell interactions in the CNS with single cell resolution.