The heart and blood are at the center of life itself. Every heartbeat sends oxygen and nutrients through a vast network of blood vessels, keeping every cell in the body alive and functioning. This powerful system known as the circulatory system is the body’s transportation network, delivering essential materials and removing waste to maintain balance and health.
vaccines may work in different ways, but they all spark an immune response. The immune response is the way your body defends itself against substances it sees as foreign or harmful. These substances include germs that can cause disease.