M-01ZH09, an oral live attenuated Salmonella enterica serovar Typhi vaccine for the prevention of typhoid fever.

Typhoid fever remains a major health problem globally, particularly in the developing world. The increased emergence of several multidrug-resistant strains of Salmonella enterica serovar Typhi has made the management of the disease increasingly difficult. Although vaccines against typhoid fever are available, improvements are desired in dosage, immunogenicity and tolerability. Emergent BioSolutions Inc is developing M-01ZH09, a single-dose oral vaccine against typhoid fever based on an attenuated strain of S enterica serovar Typhi. Several clinical trials have been completed for the vaccine, including large phase II trials in the US and Vietnam. Additionally, a phase IIc clinical trial was ongoing in India at the time of publication. The available data suggest that M-01ZH09 is well tolerated in clinical trials, and is highly immunogenic, provoking broad immune responses. Because M-01ZH09 involves administration as a single oral dose, the vaccine has the potential to be used in a mass immunization program.