Shigellosis: the current status of vaccine development

Abstract

The greatest barrier to the use of vaccine against shigellosis in developing areas is poor immune responses to oral vaccines in children who have minimal maternal antibodies. Clinical studies of promising shigellosis vaccine candidates are urgently needed after confirmation of safety, immunogenicity, and protection in volunteer challenge models.

Mucosal immunization with Shigella flexneri outer membrane vesicles induced protection in mice

“…However, development of such safe Shigella vaccine is being problematical, and no vaccine is still available [3].…”

Towards a non-living vaccine against Shigella flexneri: From the inactivation procedure to protection studies

“…Current vaccines strategies against Shigella can be grouped into two fundamental approaches: live-attenuated vaccines and nonliving vaccines [6][7][8]. While the essential concern regarding live attenuated candidates is to find the appropriate balance between immunogenicity and acceptable side effects, different scenery appears for inactivated whole cell or subunit vaccines.…”

“…In the absence of an existing effective vaccine and the ever-increasing frequency of antimicrobial-resistant Shigella strains worldwide, Shigellosis has become a major source of concern [5]. Several candidate shigellosis vaccines are currently in development including live attenuated, inactivated whole cell, or subunit vaccines [6][7][8]. Considering intrinsic risk of living vaccines, the non-living vaccine alternative, including either inactivated whole-cell or acellular approaches, results the safest direction.…”

Molecular vaccines for malaria

“…Several strains of attenuated Shigella, such as S. flexneri 2a, have been developed and used in various human clinical trials with good tolerability. 190 Alternatively, food-grade gram-positive bacteria such as Lactococcus lacti have advantages over other attenuated bacterial vaccine delivery vehicles primarily because of their inherently greater safety profiles. P. falciparum merozoite surface protein-2 (MSP2) expressed in recombinant L. lactis, either intracellularly or covalently anchored to peptidoglycan on the cell wall, elicited serum IgG antibodies that reacted with native MSP2 on the surface of P. falciparum merozoites, as detected by immunofluorescence.…”