Question

17. Which of the following is responsible for passive immunity? a. Antibody b. Helper T cells C. Vaccines containing Antigen d. Antigen Presenting Cells e. All of the above

Answer 1

Immunity is a phenomenon when an organism can counter other organism that has a potential to harm.

Immunity can be two type one is active immunity and the other is passive immunity.

Active immunity is reffered to a situation where someone get an disease causing pathogen in its own body and the immunue system of body counters the pathogen by producing antibody and memory cells(further attacks will be neutralized earlier).

Another example of active immunity is the process of vaccination to stop the spread of a pathogen(virus). Here an inactive or dead virus will be sent to body. The immunue system generates antibody and memory cell to kill and remember it respectively. Hence it is life long.

Passive immunity is different from the former one. Here body cannot generate the required amount of antibody in quick time and to treat the person antibodies from another person is required.

Example: Plasma therapy in Covid 19. Here the person who got well from covid , donates its blood from where the plasma cells are collected and provided to the ill person to treat it.

Another form of example is Antibody from mother passes to child through breast feding and by placenta.

Passive immunity is short time.

Cells help in passive immunity:

A. Antibody : It helps in passive immunity. Antibody from a person often provides to another person to treat a disease.

B. Helper T cell: Helper T cell does not come in passive immunity. Activated T cell ( Helper T cell binds with the MHC II surface showing APC) plays a role in passive immunity.

C. Vaccine containing antigen: If a person can not counter a pathogen and again it provides with the same pathogen it will do more harm. Vaccination is a part of active immunity.

D. Antigen presenting cell: The role of antigen presenting cells are to present specific antigen to our T cell and B cell to induce the activation of cytotoxic T cell and to proliferate the B cell to antibody and memory cell. But in passive immunity , activated T cell or B cell are provided. Hence APC not plays significant role in passive immunity.

Hence the right answer is --- ANTIBODY. (Antibody from a person who got recovered from the disease, provided to the ill person).