A chimeric helper nucleic acid molecule comprising helper elements from three distinct helper viruses

A chimeric helper nucleic acid molecule suitable for use in a method of producing infectious recombinant adeno-associated virus (rAAV) comprising:

• (i) an ORF from a gene of a HSV consisting of a polynucleotide encoding at least one protein of a HSV, comprising a polynucleotide encoding the UL12 protein from a HSV or the ICP8 protein from a HSV;
• (ii) an ORF from a gene of a HBoV consisting of a polynucleotide encoding the NS2 protein from a HBoV or the NP1 protein from a HBoV;
• (iii) the VA-RNA polynucleotide from an Ad;
• (iv) the E2A gene from an Ad;
• (v) the E4 gene, in particular the E4orf6 sequence, from an Ad;
• wherein each of the (i) (ii), (iii), (iv) and (v) polynucleotides are inserted as individual expression cassettes within the chimeric helper nucleic acid molecule, and wherein polynucleotides of (i) to (v) are arranged in any order and/or orientation with respect to one another;
• with the proviso that the chimeric helper nucleic acid molecule does not comprise (ii) an ORF from a gene of a HBoV consisting of a polynucleotide encoding the NS2 protein from a HBoV and the NP1 protein from a HBoV.