Shigella cause millions of cases of dysentery every year, which result in 700,000 deaths worldwide. Shigella dysenteriae serotype 1, one of about forty serotypes of Shigella, causes a more severe disease with a much higher mortality rate than other serotypes. There are no licensed vaccines available for protection against Shigella. The fact that many isolates exhibit multiple antibiotic resistance complicates the management of dysentery infections.
FDA Researchers developed a Salmonella typhi Ty21a construct comprising a Shigella dysenteriae O-specific polysaccharide (O-Ps) inserted into the Salmonella typhi Ty21a chromosome, where heterologous Shigella dysenteriae serotype 1 O-antigen is stably expressed together with homologous Salmonella typhi O-antigen. The constructs elicit immune protection against virulent Shigella dysenteriae challenge, as well as Salmonella typhi challenge. The construct can be used as a new vaccine candidate, stable for vaccine manufacture, and provides combined protection against enteric fevers due to Salmonella typhi and Salmonella sonnei.
|Potential Commercial Applications||Competitive Advantages|
Development Stage: in vivo, mouse challenge studies
Inventors: Dennis Kopecko, De Qi Xu
“Core-linked LPS expression of Shigella dysenteriae serotype 1 O-antigen in live Salmonella Typhi vaccine vector Ty21a: preclinical evidence of immunogenicity and protection.” Vaccine 2007 Aug;25(33):6167-75 PMID: 17629369
United States Patent: 8,071,113, issued 12.06.2011
United States Patent: 8,337,831, issued 12.25.2012
United States Patent: 8,790,635, issued 07.29.2014
United States Patent: 8,968,719, issued 03.03.2015
United States Patent: 9,402,889, issued 08.02.2016
European Patents: 1756149, issued 09.04.2013
Product Area: Biologics, Vaccines
FDA Reference No: E-2004-022
Ken Millburne, J.D. FDA Technology Transfer Program