Patent ID: 7189401

Claim:
A coxsackievirus genome having a pol gene that encodes an RNA-dependent RNA polymerase, the genome being modified to produce an attenuated virus, the genome further comprising at least one pol gene modification that causes the polymerase to have increased fidelity as compared with a polymerase from a coxsackievirus genome that does not comprise the pol gene modification, wherein said pol gene modification results in an amino acid change in the RNA-dependent RNA polymerase selected from the group consisting of GLY328SER, GLY328CYS, GLY328ALA, GLY328LEU, GLY328ILE, TYR327PHE, LEU194VAL and GLU213GLY, wherein the increased fidelity results in a decreased reversion rate from attenuated virus to non-attenuated virus as compared with an equivalent coxsackievirus genome without the pol gene modification.