Viral vectors
Viruses have become some of the most efficient vehicles for transferring genetic information into eukaryotic cells. In this context, molecular biologists have devoted much effort to modifying their genome to make them safer (incompetent for replication, attenuation) but maintaining their abilities to transfer and express recombinant genetic material. Thus, viral vectors have become a very useful tool in biomedical research both in vitro (cell cultures) and in vivo (experimental animals, gene therapy). However, we should be aware that the improvements in the intrinsic biosafety and the commercial availability of these vectors can facilitate a relaxation in the application of safety practices, a circumstance that must be avoided.