Antigenic substances that act against specific defenses are called tolerogens.

All foreign substances that cause allergies are called allergens.

A substance that binds to an antibody by itself as an antigen is called a hapten.

The part of the antigen that binds to the antibody is called the antigenic determinant or epitope.

Those cells that remember the attack strategy of the bacterium and develop resistance when the attack of that bacterium occurs later are called memory cells or memory cells.

Memory cells are long-lived lymphocytes. It is of two types. T-lymphocytes and B-lymphocytes. T-lymphocyte cells are produced in the bone marrow and spread throughout the body via the blood or lymph. They activate the body’s immune system and directly attack disease-causing viruses and bacteria. B-lymphocyte cells produce plasma cells through repeated division. Plasma cells make antibodies. These antibodies inactivate or kill the bacteria.

When the disease first occurs, the memory cells cannot develop any resistance against the germs. Because the memory cells do not contain any antibodies against the antigens of the bacteria. During this time the memory cells contain the process of antigen recognition. These cells work as memory cells in the body. Then the cell divides in the process of mitosis to form a colony. Later, when germs enter the body, the memory cells identify and destroy the germs.

Vaccines are made from live, semi-inactivated or dead viruses or bacteria. However, most vaccines are made from viruses. Vaccines are made from any disease-causing bacteria. Vaccines do not cause disease when administered to animals. But it produces antibodies. The antibodies produced prevent the bacteria from multiplying. Permanently destroys bacterial activity. As a result, the body does not get sick.

Vaccination is the method of inoculation to prevent disease. The use of vaccines in the treatment of diseases is called vaccinotherapy. The World Health Organization (WHO) has adopted a six-disease vaccination program for children worldwide. These are diphtheria, whooping cough, whooping cough, polio, measles and tuberculosis. UNICEF EPI (Expanded Program on Immunization) is implementing the immunization program through the program.

The vaccine made by two different components of the virus is called Conjugate vaccine. E.g. Haemophilus vaccine.

This vaccine is made from a small part of the germ cell (protein). E.g. Hepatitis B, Papilloma Virus Vaccination.

Toxoid vaccine is made by inactivating the toxic substances of bacteria with formaldehyde. For example, vaccination against diphtheria, tetanus, etc.