ORF7 deficient varicella virus, vaccine comprising the virus and use thereof

1. A method for preparing a mutated vaccine for varicella and/or herpes zoster comprising:

providing a varicella virus wherein the ORF7 sequence of the varicella virus DNA is mutated which causes a loss of ORF7 function and/or expression,

the ORF7 sequence is mutated by whole deletion or partial deletion of the ORF7 sequence, or inserting a stop codon into the ORF7 sequence, and wherein the varicella virus is not able to infect sensory ganglion;

infecting a cell with the varicella virus; harvesting the infected cell via digestion;

centrifuging the harvested infected cell;

adding protection agents to the centrifuged harvested cell;

clarifying the centrifuged harvested cell with protection agents; and

forming the vaccine from the clarified harvested cell.

2. A method of inducing an immune response to a varicella virus, comprising administering to a patient in need thereof with an effective amount of the vaccine produced by claim 1 .