Virus strains

Use according to any one of the preceding claims wherein said non-laboratory virus strain is a strain of a herpes virus, adenovirus, picornavirus, retrovirus or alphavirus.

Use according to any one of the preceding claims wherein said non-laboratory virus strain further comprises a heterologous gene.

Use of a modified, replication incompetent, non-laboratory virus strain comprising a heterologous gene in the manufacture of a medicament for the delivery of said gene to a subject.

Use according to claim 27 wherein said strain is an HSV strain and said immediate early gene is, or genes are, one, two, three, or all of the genes encoding ICP0, ICP4, ICP22 and ICP27.

A method of producing a modified non-laboratory virus strain comprising:

• (i) providing a non-laboratory strain of a virus;
• (ii) modifying it to render it replication incompetent and,
• (iii) inserting a heterologous gene.

HSV1 strain JS1 as deposited at the European Collection of Cell Cultures (ECACC) under provisional accession number 01010209, or an HSV1 strain derived therefrom.