Question

Introduction of attenuated pathogens in human body results in
A. Artificial acquired active immunity
B. Artificial acquired passive immunity
C. Natural acquired active immunity
D. Natural acquired passive immunity

Answer 1

Hint: We have to remember that an attenuated vaccine is a vaccine developed by reducing a pathogen's virulence while still keeping it viable. Attenuation takes and modifies an infectious agent to make it harmless or less virulent. These vaccines are in contrast to those developed by the virus (inactivated vaccine) being 'killed'.

Complete answer: We know that the passive immunity acquired artificially is resistance acquired by providing an injection or transplantation of antibodies made by someone else to a person. Naturally acquired active immunity occurs when, as a result of the primary immune response, the organism is exposed to a live pathogen, contracts the disease, and becomes immune. During pregnancy, naturally acquired passive immunity occurs in which some antibodies in the form of IgG are transferred from the maternal blood into the foetal bloodstream.
The constituents of vaccines are dead or alive but attenuated pathogens, toxoids or toxins exuded by the pathogens. The immunity obtained artificially through vaccination is considered artificially acquired active immunity by the injection of attenuated pathogens. These vaccines stimulate the production by the immune system of antibodies that are capable of protecting the organism from a disease.
So, the correct answer is “Option A”.

Note:
When we need to generate antibodies and memory cells, the antigens in the vaccine activate the immune system. It is aimed directly against the antigens in the vaccine. If the live infectious agents with the same antigens that were in the vaccine enter the body of the person after the immunization, the right antibodies are still present and they bind to the infectious agents. The memory cells produce a rapid immune response from the rest of the immune system, and the infectious agents are swiftly attacked and destroyed, frequently before symptoms of the disease can develop.