IL5 and helminthiasis: The protection of mice immunized with As16 formulated with Alhydrogel was associated with high level of IgG1 and IL-5, further confirming the Th2-type immune responses contribute mainly to the protective immunity of As16 against A. suum infection, This finding is consistent with other studies showing that a Th2-type response is critical in achieving protective immunity against helminthic infections [45–47].