The invention provides safer vaccines that induce less adverse reactions particular the serious adverse reactions in a host. Also provided are compositions including these safer vaccines, as well as polynucleotides, vectors, host cells, methods, and kits related thereto. Further provided are methods and kits for preventing or treating infectious diseases, infection-relating diseases, and adverse reactions of vaccines in an individual by administering to the individual a safer vaccine that induce less adverse reactions, or by administering to the individual a pathogenic antigen that neutralize pathogenic antibodies. Yet further provided are methods for identification of the presence of pathogenic antibodies inducible by a pathogen or the vaccines relating to the pathogen.