Construction and characterization of attenuated delta aroA delta virG Shigella flexneri 2a strain CVD 1203, a prototype live oral vaccine

Engineered and construction of pDS132::∆virG as suicide vector for targeted gene deletion of virG from Shigella flexneri 2a in order to generation a live attenuated Shigella vaccine

Background & Objective: Shigella are Gram negative bacteria capable of inducing their entry into non-phagocytic cells via secretion of various effector proteins called invasion plasmid antigens (Ipas). The most important of them is VirG protein. Live attenuated Shigella vaccines have indicated promise in inducing protective immune responses in human clinical trials. In current situation, const...

Shigella flexneri 2a strain CVD 1207, with specific deletions in virG, sen, set, and guaBA, is highly attenuated in humans.

A phase 1 clinical trial was conducted among 35 healthy adult volunteers to evaluate the safety, immunogenicity, and shedding of different doses of CVD 1207, a live attenuated Shigella flexneri 2a vaccine candidate with specific deletion mutations in virG, sen, set, and guaBA. CVD 1207 retains the ability to invade epithelial cells but cannot effectively spread intercellularly after invasion (D...

Further Characterization of DaroA DvirG Shigella flexneri 2a Strain CVD 1203 as a Mucosal Shigella Vaccine and as a Live-Vector Vaccine for Delivering Antigens of Enterotoxigenic Escherichia coli

Vaccination against shigellosis with attenuated Shigella flexneri 2a strain SC602.

The Shigella flexneri 2a SC602 vaccine candidate carries deletions of the plasmid-borne virulence gene icsA (mediating intra- and intercellular spread) and the chromosomal locus iuc (encoding aerobactin) (S. Barzu, A. Fontaine, P. J. Sansonetti, and A. Phalipon, Infect. Immun. 64:1190-1196, 1996). Dose selection studies showed that SC602 causes shigellosis in a majority of volunteers when 3 x 1...

Construction of prophylactic human papillomavirus type 16 L1 capsid protein vaccine delivered by live attenuated Shigella flexneri strain sh42.

To express human papillomavirus (HPV) L1 capsid protein in the recombinant strain of Shigella and study the potential of a live attenuated Shigella-based HPV prophylactic vaccine in preventing HPV infection, the icsA/virG fragment of Shigella-based prokaryotic expression plasmid pHS3199 was constructed. HPV type 16 L1 (HPV16L1) gene was inserted into plasmid pHS3199 to form the pHS3199-HPV16L1 ...