The invention provides an eye-drop vaccine for therapeutic immunization of a mammal comprising Copolymer 1, a Copolymer 1-related peptide, or a Copolymer 1-related polypeptide, for treating neuronal degeneration caused by an injury or disease, disorder or condition in the central nervous system (CNS) or peripheral nervous system (PNS), for preventing or inhibiting neuronal secondary degeneration which may otherwise follow primary injury in the CNS, for promoting nerve regeneration in the CNS or in the PNS after an injury, disease, disorder or condition or for protecting CNS and PNS cells from glutamate toxicity.