Question

Many deadly diseases of the past are no longer a threat due to the development and use of vaccinations. Describe the mechanism and purpose of immunization vaccines and booster shots. Include the specific cells and processes involved. Describe the type of immune response and antibodies represented with vaccinations. Be sure to include an application.

Answer 1

Immunization vaccination is an artificial method of increasing the immunity against a specific disease by injecting or ingesting the dead pathogen/ genetic material of pathogen/Toxoid/ any part of the pathogen/ live attenuated pathogen(reduced virulence of microbe). The body will try to fight against these newly introduced agents and make fit to get an immense amount of response against those pathogens.

Booster shot is a Very tiny amount of vaccination taken in multiple regular intervals.

• Rabies vaccine is an example for inactivated /killed form of the microorganism used as the antigen.
• MMR vaccine, Tuberculosis vaccine, polio vaccine, Yellow fever vaccine are examples for attenuated type of vaccine. No booster shot is required here.
• Hepatitis B vaccination is an example for subunit vaccine that uses dead non-pathogenic bacteria to produce the adaptive immunity.
• Toxoid (inactivated toxin) vaccination is used in Tetanus toxoid injection.

The mechanism that occurs in our body is:

1.Innate immunity: which may fail to prevent the invasion of the antigen (vaccine)

2.Adaptive immunity:Specific Antibodies against those antigen/pathogen are produced in the body to kill them.

Vaccines are deactivated form of the microbes (decreased virulence of microbes) or some protein/genetic material is inserted into the body. Our body detects the antigen and develop immunity against that particular pathogen. Active immunization.The immunity will be developed within a few weeks. Some memory cells keep the memory of this pathogen and use it to produce the antibodies against this pathogen in a future infection. This procedure can be done in the animals and antibody is extracted from it and is used for direct injection into the body to gain a passive immunity. e.g.. Snake venom is injected into the horse and the antibody against it(anti-venom) is extracted and injected into the body to save the life.

When the vaccine is injected into the body, macrophages try to destroy them by engulfing. B- lymphocytes will multiply and produce large number of antibody molecules which attaches to the antigen molecule. This antigen - antibody complex helps the complement system to detect it and destroy them. B-cell mediated humoral immunity work out here and when exposed to the antigen, it produces a slow immune response against the antigen. But following this exposure, Memory B-cells will memorize this antigen and react when the same pathogen reappears. Vaccines work by exploiting the immune system's memory. Actually this memory property of B-cells are utilized in the mechanism of vaccination.

E.g.. Typhoid antigen is produced by producing a toxoid (Deactivated toxin) salmonella typhi bacteria which enters into our body and memory cells are generated. If in future time originally salmonella typhi attack in our body, this toxin will be released, the memory B-cells will recognize it and destroy them.