De novo generation of viruses in animals: from infection models to vaccine development.

Reverse genetics is a valuable research tool in the field of virology with numerous applications. Primarily employed to recover viral strains in vitro, these approaches have also been used to generate viral strains directly in animals. This review presents a historical and technical overview of publications describing the rescue of viruses from injection of nucleic acids directly into animals since the 1950s. The injection of purified or cloned viral genomes in vivo has enabled the generation of many pathogens in a wide range of animal models. Recent advances in the delivery process of nucleic acid into cells have also contributed to this field of virology research, which currently focuses on creating a new generation of vaccines called DNA-launched live attenuated vaccines (LAVs). This new approach simplifies the administration of existing or newly created LAV strains, while providing better control of the inoculated material.