Diarrhea incidence, clinical symptoms, and protective efficacy in Aotus nancymaae orally immunized with live-attenuated SC602 vaccine strain or S. flexneri 2a strain 2457T and then challenged with S. flexneri 2a 2457T

Treatment (CFU dose)No. of animalsDiarrhea incidence (%)aClinical symptoms (%)bProtective efficacy (%)cP valued
SC602 (1 × 1010)7e1414800.05
SC602 (1 × 1011)7e1414800.05
S. flexneri 2a 2457T (1 × 109)83838460.34
  • a Diarrhea defined as at least one loose-watery stool on at least two consecutive days during the observation period (10 days).

  • b Clinical symptom defined as diarrhea, bloody stools for 2 days, or death.

  • c Protective efficacy = [(percentage of clinical symptoms of the control group − percentage of clinical symptoms in the vaccinated group)/(percentage of clinical symptoms of the control group)].

  • d Fisher's exact test compared to the PBS control group.

  • e One animal excluded from data analysis due to diarrhea for 2 days prior to challenge.