NUCLEIC-ACID IMMUNIZATION - A PROPHYLACTIC GENE-THERAPY

Nucleic acid (NA) vaccines may offer the safety of subunit or inactivated vaccines and, at the same time, provide the advantages of live recombinant vaccines, such as induction of a protective cellular immune response. In Germany, the so-called 'Gene Law' regulates the genetic modification of organisms such as prokaryotic or eukaryotic cells for the construction of recombinant NAs intended for use as NA vaccines. Neither NAs nor human beings treated with NAs are subject to Gene Law regulations but preclinical laboratory experiments are regulated by the Gene Law. Gene therapy, as defined in a recent draft of a European guideline for the production of gene therapeutics, includes the genetic modification of human somatic cells via transfer of NAs and thus includes NA vaccines. The guideline provides recommendations for the production of NA vaccines for human use and for preclinical safety testing. NA vaccines are products derived by biotechnological processes, as defined in part A of the annex of Council Regulation (EEC) No. 2309/93 of 22 July 1993. Applications for marketing authorization in Member States of the European Union will thus be reviewed by the European Agency for the Evaluation of Medicinal Products starting from 1 January 1995. Inoculation of NAs encompassing a full-length but int/nef-defective simian immunodeficiency provirus allowing limited replication of viruses released is being investigated at the Paul-Ehrlich-Institute as a model for NA vaccine against AIDS. The system may offer a promising way towards a vaccine and will also be used to study safety requirements for future human use of NA vaccines.