Recombinant vaccines against the mononegaviruses--what we have learned from animal disease controls.

The mononegaviruses include a number of highly contagious and severe disease-causing viruses of both animals and humans. For the control of these viral diseases, development of vaccines, either with classical methods or with recombinant DNA virus vectors, has been attempted over the years. Recently reverse genetics of mononegaviruses has been developed and used to generate infectious viruses possessing genomes derived from cloned cDNA in order to study the consequent effects of viral gene manipulations on phenotype. This technology allows us to develop novel candidate vaccines. In particular, a variety of different attenuation strategies to produce a range of attenuated mononegavirus vaccines have been studied. In addition, because of their ideal nature as live vaccines, recombinant mononegaviruses expressing foreign proteins have also been produced with the aim of developing multivalent vaccines against more than one pathogen. These recombinant mononegaviruses are currently under evaluation as new viral vectors for vaccination. Reverse genetics could have great potential for the preparation of vaccines against many mononegaviruses.