Question

Give application of a vaccine.

Answer 1

The term vaccine has been derived from Latin word “vaccinus” meaning “from cows”. Transfer of vaccine into the body of an organism is called vaccination. The term vaccination was used by Edward Jenner for protective inoculation. He also used the term vaccine for cowpox which is a wilder form of smallpox.

Complete answer:
Vaccines contain dead or weakened pathogenic organisms (microbes) or their products. When vaccines are introduced into a normal healthy person, it induces antibodies that provide acquired immunity against subsequent infection from that specific organism. The difference is that the individual does not suffer the symptoms and dangers of the full-strength disease. The antibodies remain in the body and individuals remain protected from the pathogenic organisms.

Application of vaccine is as follows:-
- It is used to induce long term humoral as well as cell-mediated immune response against disease-causing pathogens.
- Vaccines help in developing immunity against specific diseases.
- It initiates a primary immune response, generating memory cells without making a person ill. Later, if the same or very similar pathogens attack, a specific memory cell already exists. They recognize the antigen and evoke secondary immune response producing large numbers of antibodies that quickly overpower the invaders.
- The immune system is strongest in adulthood that means infants; children and elderly are particularly susceptible to a dangerous infection. Vaccines strengthen their immune system and bypass this risk.
- The use of vaccines has been effective in developing resistance of infection of microorganisms that cause cholera, diphtheria, measles, mumps, whooping cough, rabies, smallpox, tetanus, typhoid, yellow fever and poliomyelitis.
- Vaccines can be a key tool in managing threat or pandemic situations such as Covid-19 caused by a coronavirus.

Additional information:
Both bacterial and viral vaccines have been developed by scientists:-

Bacterial vaccines:- These maybe
- Live vaccines like BCG for TB
- Killed vaccines like T.A.B. (typhoid-paratyphoid A and B) for enteric fever
- Bacterial products like toxoids for diphtheria and tetanus

Viral vaccines:- These are
- Live vaccines like the oral polio vaccine
- Killed vaccine like Salk vaccine
- Subunit as vaccine-like Hepatitis-B vaccine.

Note: Vaccination has almost completely wiped out some deadly disease such as diphtheria and polio. In fact, smallpox has been eliminated worldwide, thanks to an international effort by the World Health Organization.