(c)++Immunity+&+vaccination



=//Immunity and  Vaccination //=

//**Virus** is an organism that causes disease. // //**Pathogen** is anything that causes a disease. //

//** What happens when a virus attacks our body: **// When a virus attracts our body, it attacks our cells. Unaware of the intrusion, our cells continue to perform daily activities, leading to the production of more and more viruses. If there are too many of them on the cell, it will explode and spread them to our body.

 //**Figure 1** - Viruses attacking the human cell.//

//** What happens when a pathogen attacks our body: **// When attacked by a pathogen, a protein on the surface of that pathogen, known as an **antigen** triggers our system. Our white blood cells, known as **lymphocytes** release a type of protein called **antibodies** in response to the antigen. This usually occurs after 3 - 10 days. Each type of antigen stimulates the production of a specific antibody that is in charge of destroying that one antigen. This is because our lymphocytes create antibodies that fit only one type of antigen.

 //**Figure 2** - Diagram of an antibody.//

//** What is immunity? **// Immunity is how one's body produces antibodies to fight against infections of pathogens. This can be more easily achieved with the use of vaccination, which is when a chemical is injected into the body to promote the production of the correct antibodies.

//** What does it mean to be immune? **// After one’s body is infected by a pathogen, it keeps some of the lymphocytes that was used to combat the antigen. This way, the body will be able to “remember” how to protect itself the next time it is attacked by that same antigen. This “memory” is able to last for a long amount of time, sometimes even years. Hence, the body is considered **immune** to this type of disease.

//** Types of immunity: **// and although it does not cause the disease, it will allow the body to make antibodies for that pathogen. The body is now immune to that type of disease as it has learnt to make that specific type of antibodies.
 * Active:** The individual's body makes its own antibodies.
 * //** Natural: **//The individual’s body was infected by a pathogen and has made antibodies to combat it. The body is now immune to that type of disease.
 * //** Artificial: **// The body has been vaccinated. The weakened pathogen is injected into the individual’s body,


 * Passive:** The individual's body is given antibodies that were already made.
 * //** Natural: **// The mother consists of the antibodies from the mother’s body. The child will then be temporary immune to the pathogens that the mother has already produced antibodies for.
 * //** Artificial: **// Antibodies that are collected from the blood of animals in laboratories are stored under the form of serum and injected into the adult’s body, making them immune to this pathogen. This is used when the disease spreads too rapidly and the immune system is unable to fight against it. However, this method only provides a temporary immunity, as the body is not actually making these antibodies itself.

//** What is vaccination? **// Vaccination is a chemical or cell that we inject into our body in order to stimulate the product of antigens that combat specific pathogens. Vaccinations protect you from specific diseases that can make you very sick, disabled or even kill you. They boost your body's defense system, which is known as the **immune system**. Vaccines create immunity that protects us from getting those diseases without having to suffer from the disease in the first place. Sometimes, vaccines are called immunizations, needles or shots.

 //**Figure 1** - A person getting a vaccination.//

//** How are vaccines produced? **// There are many different ways as to how a vaccine can be produced. Some of which are:
 * dead pathogens
 * weakened pathogens
 * proteins from the pathogen's surface (these are also recognized by lymphocytes)

Sometimes, as mentioned above, diseases can be very fast-acting - to quick for our immune system to respond. In these cases, another individual's or an animal's antigens are injected into the body for an immediate reaction. However, this is only a temporary immunity because these antigens are foreign to our body. Hence, the body will not keep it as "memory" for the next time it is attacked by the same pathogen.

//** How do vaccinations work? **// Most vaccines contain a little bit of a disease germ that is weak or dead. Vaccines do NOT contain the type of germ that makes you sick. Some vaccines do not contain any germs. Having this little bit of germ inside your body helps strengthen your immunity system. Vaccines trick your immune system into producing antibodies to combat certain pathogens from diseases even though your body is **not** attacked by that disease. It contains either dead, weakened or proteins on the surface of pathogens in order to trigger the immune system stimulate the product of antibodies, which will then be memorized by your body, making it immune to later attacks by that specific disease.

At the moment, the most common method of getting vaccines is by injecting it with a syringe. However, scientists are looking at new ways to give vaccines, such as by mouth of with nose sprays.

//**Watch the following video for more information about vaccination:**//

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