Easy defence against pathogens: Phagocytes

Active immunity: T-cells and B-cells

There are different kinds of white blood cells (lymphocytes):

T-cells                and                    B-cel


T-cells’ job:

The T-cells identify the antigen on the surface of the pathogen. They have something like antibodies on their surface and catch the pathogens and destroy them.

They also inform the B-cells against the pathogen and make them produce antibodies and multiply.


B-cells’ job:

The B-cells are able to produce antibodies. There are about 10 million different B-cells. The T-cell informs the right one against the specific pathogen and makes them produce antibodies and multiply.



Active and passive immunity




At the doctor’s you can get immunised against pathogens with a vaccine.

There are two ways to get immune.


Active immunity


A vaccine contains dead or inactive pathogens. These pathogens still have antigens on their surface, so that the immune-reaction of station 5 still works. You get immune but won’t get ill, as the pathogens are dead. Sometimes you have to get vaccinated two or three times to make the body react to the antigens again. Every time of vaccination the number of memory cells get higher and the reaction to the real/living pathogen will be faster.


Passive immunity


With passive immunity you don’t get infected with the real pathogen. The doctor injects antibodies against the pathogens itself. This is only used if the infection has happened and the doctor wants to give the body a rapid/fast protection against the pathogen.

Interactive Immune system

How immunity works