8. It can be said that a vaccine does not prevent infection; rather it primes the immune system to respond to an invader. Using information about human immune response, explain this statement. Mention what happens in the body from the time of vaccination through contact with the infectious agent.

the aorta is the large artery leaving the heart branches into smaller arteries, which eventually branch into capillaries.the arteries carry oxygen and nutrients away from your heart, to your body's tissues. the capillaries are small, thin blood vessels that connect the arteries and the veins. the statement that arteries carry oxygen-rich blood to capillaries is true. veins on the other hand are blood vessels that take oxygen-poor blood back to the heart.