| abstract |
PCT No. PCT/US93/03615 Sec. 371 Date Dec. 20, 1994 Sec. 102(e) Date Dec. 20, 1994 PCT Filed Apr. 13, 1993 PCT Pub. No. WO93/21306 PCT Pub. Date Oct. 28, 1993The present invention relates to engineering attenuated viruses by altering a non-coding region or the coding sequence of a viral gene. Alterations of the non-coding regions which regulate transcription and/or replication are described. These alterations result in the down-regulation of the viral gene and an attenuation of the virus, either by the production of defective particles during replication, or by reducing the number of progeny virions produced during viral replication. Alterations of viral coding sequences are also described which result in a recombinant or chimeric attenuated virus. |