LIVE ATTENUATED VACCINES BASED ON cp45 HPIV-3 STRAIN AND METHOD TO ENSURE ATTENUATION IN SUCH VACCINES

摘要

The present invention is based upon correlation of two attenuating lesions of the cp45 strain to specific defects in the genome of cp45. Specifically, a significant level of attenuation of cp45, resulting from its temperature-sensitive and cold-adapted phenotypes is associated with mutation of the L gene of cp45. A second mutation in the gene coding for hemagglutinin-neuraminidase (HN) in the cp45 strain has also been found to be another attenuating mutation. The correlation of these two attenuating lesions of cp45 to specific genes enables several practical applications. It is now possible to create attenuated vaccines directed at other wild-type HPIV-3 viruses and other viruses other than HPIV-3 by incorporating the mutated L and/or HN genes of cp45 in to a target virus genome or alternatively, expressing surface antigen genes from other viruses in cp45.