Question

Passive immunity is defined as immunity

• A. Achieved through vaccination
• B. Achieved through the serum of other animals enriched in antibodies
• C. Inherited from the parents
• D. Acquired through first exposure to the disease

Answer 1

The correct option is B

Achieved through the serum of other animals enriched in antibodies

The correct option is B.

Explanation of the correct option:

1. Passive immunity is achieved by directly administering prepared active antibodies to fight pathogens.
2. Passive immunity is the act of transferring preformed antibodies from a host animal to a recipient animal, such as that animal's progeny or even an animal of a different species.
3. The term "passive immunity" refers to immunity acquired through the antibody-rich serum of other animals.
4. It is a sort of defense based on antibodies produced in a different host.

Explanation of the incorrect option:

Option A:

1. Vaccines are an example of active immunity.
2. After being exposed to weakened microorganisms, the body produces antibodies.
3. Active immunity occurs when antibodies are generated within the body in response to antigen exposure.
   

Option C:

1. Colostrum and breast milk, which include IgA antibodies that are transported to the infant's gut and provide local defense against disease-causing bacteria and viruses until the newborn can synthesize its antibodies, are further sources of passive immunity.
2. Antibodies from mothers are transferred to their unborn children through the placenta during the final three months of pregnancy.
3. IgA-enriched colostrum, a yellowish fluid released by breastfeeding women during the first days of lactation, is an example of passive immunity.
4. Because the infant has received antibodies rather than producing them on its own, this sort of immunity is referred to as passive immunity.

Option D:

1. Natural immunity is built up through exposure to the disease-causing agent and subsequent disease-related illness.
2. Through vaccination, a dead or compromised version of the disease organism is introduced, resulting in the development of vaccine-induced immunity.

Final answer: Passive immunity is defined as immunity achieved through the serum of other animals enriched in antibodies.