If the hookworm vaccine provides sterilizing immunity (total protection against reinfection) the presence of fecal egg counts is sufficient to analyze the efficacy of the vaccine. An efficacious vaccine may be non sterilizing yet continue to reduce the concentration of larvae that reach the GI tract and develop into parasitic worms. There is a strong correlation between egg counts, host worm burden and host blood loss which can be used to analyze fecal heme. Important end points necessary to analyze efficacy of the Na-ASP-2 vaccine include:

• Fecal egg counts
• Fecal heme
• Hematological parameters