Hello Lillyanna,
fasting will divert the energy away from digestion into the Immune System, and with the accompanying cleansing that fasting affords will make you immune to the swine-flu.
In addition, good nutritional supplementation will achieve the same benefits by taking at least 5000ius of Vitamin D3 per day, along with a good all-around Multivitamin/mineral after the fast is broken.