Immunity: The Body's Army

This micro-course explains immunity as a coordinated defense system, using the roles of white blood cells, antibodies, T-cells, and immune memory. You will learn how innate and adaptive immunity differ, why a cold is not the flu, and how vaccines train the body for future encounters. The course also connects immunity to the microbiome and everyday exposure to microbes. After completing it, you will be able to describe how immune responses unfold, interpret common misconceptions about germs, and explain vaccine basics clearly.