Prevention Vaccination after age 12 weeks is generally effective in
generating immunity against this infection, though immunity gained from mother's milk may inactivate the vaccine through age 14 to 16 weeks.
Th1 cells produce interferon - gamma, which plays an important role in anti-tumor
immunity and in defending
against intracellular pathogens, whereas Th2 cells
generate IL - 4, IL - 5, and IL - 13, which protect
against parasitic
infections and help mediate antibody responses.