Abstract: The present invention provides chimeric viral vectors which have both the capacity to infect host cells efficiently and the capacity to integrate their genomic material into the host cell's genome. The invention provides a chimeric viral vector which comprises a functional packaging signal derived from a first virus and an integration derived from a second virus. Typically, viruses capable of integrating their material into a host cell genome, having additional genetic material introduced therein by recombinant process, do not have much room for insertion of such additional genetic material or are not very well capable of infecting every wanted host cell. Infecting viruses also lack a high insertion capacity or integration into the host cell's genome. The present invention provides integration of large inserts into a host cell's genome at an efficient infection rate by combining the properties of efficiently infecting viruses with efficiently integrating viruses.