Question

What is vaccination? What is the role of vaccines in body? Give two examples when immediate response is needed by body to defend it, name this type of immunization.

Answer 1

(a) Vaccination is a procedure that presents the immune system with a harmless variant of a pathogen, thereby stimulating the immune system to mount a long-term defense against the pathogen. Thus, it is an antigen-specific stimulation of the host immune response to prevent infectious disease.

(b) A vaccine is a harmless variant of a pathogen that stimulates a host's immune system to mount defenses against the pathogen. A vaccine produces active immunity.

When a person is vaccinated, the immune system works to produce antibodies and activate other immune cells to certain pathogens. If the person encounters that pathogen again, long-lasting immune cells specific to it will already be primed to fight it.

(c) Passive immunization results when a person is given someone else’s antibodies. When these antibodies are introduced into the person’s body, the “loaned” antibodies help prevent or fight certain infectious diseases. The protection offered by passive immunization is short-lived, usually lasting only a few weeks or months. But it helps protect right away.

Examples:

i. In babies, a passive immunity is given in the form of antibodies from the mother to the baby via the umbilical cord. The baby, having a weak and newly developing immune system, requires antibodies from the mother to defend off infections until the immune system is strong enough to provide an active immunity to the same diseases.

ii. Antivenom as a Passive Immunity:

If you were bitten by a rattlesnake, there would be a chance you could be injected with the snake’s venom.

In this case, your best hope for survival would be the administration of an anti-venom. These serums contain a high number of venom antibodies, or proteins, that are able to bind to the venom, removing it from the bloodstream and tissues. In this way, the high load of venom delivered to your system can be dealt with by a shot or series of shots.