IMMUNOLOGY

Detailed explanation-1: -In the primary response to infection, antibodies are secreted first from plasma cells. Upon re-exposure to the same pathogen, memory cells differentiate into antibody-secreting plasma cells that output a greater amount of antibody for a longer period of time.

Detailed explanation-2: -The type of virus or bacteria to which you are first exposed is the version your immune system will tend to remember the best. So when you are exposed to a second or third type of the pathogen, your immune system will react as if it is still recognizing the first type.

Detailed explanation-3: -In secondary responses, on antigen rechallenge, memory B cells are activated and have at least two fates: they either differentiate into long-lived plasma cells or enter GCs to undergo rounds of population expansion, SHM and selection (Fig.

Detailed explanation-4: -B lymphocytes are the cells of the immune system that make antibodies to invading pathogens like viruses. They form memory cells that remember the same pathogen for faster antibody production in future infections.

Detailed explanation-5: -During the secondary immune response, these cells are involved in the reaction against foreign antigens, including pathogens, and take part in autoimmune diseases, but also are crucial to immunological tolerance and vaccine therapy.

Detailed explanation-6: -The primary immune response occurs after the first exposure to an antigen. A primary immune response results in the generation of memory immune cells. A secondary immune response occurs as a result of a second exposure to an antigen.