For the study, a total of 151 Vietnamese children between five and 14 years of age were enrolled. A total of 101 children received the vaccine candidate and 50 children received placebo. Study results showed that 97% of the children dosed developed an immune response, which was defined as an increase in Salmonella typhi LPS-specific IgG antibody levels and/or Salmonella typhi LPS-specific IgA antibody levels in the blood, suggestive of systemic and mucosal protective immunity, respectively. This represented a statistically significant difference from the placebo group.
There were no safety concerns following administration of a single dose of the drinkable typhoid vaccine candidate. The proportion of subjects reporting adverse events was similar for the vaccinated group (26%) and placebo group (22%); this difference was not statistically significant.
Fuad El-Hibri, chairman and CEO of Emergent BioSolutions, said: “We are pleased that the full analysis of the data from this Phase II study reaffirms that our typhoid vaccine candidate met the pre-established clinical endpoints. These data are encouraging and indicate great promise regarding both the safety and efficacy of what would be the first single-dose, drinkable typhoid vaccine.”