1. Vaccinations, white blood cells, antibodies By Alex Hayes

2. Vaccinations Vaccines help a body's immune system prepare in advance to fight infectious illnesses and potentially deadly diseases caused by infectious agents or their by-products. Essentially, vaccines give the body a preview of a bacterium, virus, or toxin allowing it to learn in advance how to defend itself against that potential invader. If the body is ever infected by that particular pathogen after the vaccine has done its work, the body's immune system is ready to protect us because it has created "memory cells" when exposed to the vaccine. These cells can tell your immune system exactly what antibodies it needs to make for that particular pathogen and can get to work before the infection gets out of control.

3. What a vaccination contains a vaccination contains either a dead or inactive form of the potential invading microbe. These components of the vaccine are called the antigens that trigger a response from the immune system.

4. What are White blood cells White blood cells (WBCs) are a part of the immune system and help our bodies fight infection. They circulate in the blood so that they can be transported to an area where an infection has developed. In a normal adult body there are 4,000 to 10,000 (average 7,000) WBCs per microliter of blood. When the number of WBCs in your blood increases, this is a sign of an infection somewhere in your body

5. antibodies An antibody is a large Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, called an antigen. Each tip of the "Y" of an antibody contains a paratope (a structure analogous to a lock) that is specific for one particular epitome (similarly analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by other parts of the immune system, or can neutralize its target directly (for example, by blocking a part of a microbe that is essential for its invasion and survival). The production of antibodies is the main function of the hormonal immune system.