PATHOLOGY

Detailed explanation-1: -The major advantage to passive immunity is that protection is immediate, whereas active immunity takes time (usually several weeks) to develop. However, passive immunity lasts only for a few weeks or months. Only active immunity is long-lasting.

Detailed explanation-2: -In addition to “fighting off” these pathogens, active immunity is important because it lasts a long time in the form of immunologic memory. Immunologic memory consists of B and T cells that can recognize a particular pathogen (see “Adaptive immune system").

Detailed explanation-3: -Whereas active immunity refers to the process of exposing the individual to an antigen to generate an adaptive immune response, passive immunity refers to the transfer of antibodies from one individual to another. Passive immunity provides immediate but short-lived protection, lasting several weeks up to 3 or 4 months.

Detailed explanation-4: -The greatest downside to passive immunity is that these antibodies don’t stay in the body for very long. Because your body isn’t continually reacting to specific pathogens, the antibodies that fight them will die off without restocking.

Detailed explanation-5: -Vaccines train your immune system with a harmless form of the virus, which creates a memory of that specific virus so when you encounter the real virus in the future, it responds faster and more efficiently to prevent infection and stop you from getting seriously sick. This is long-term immunity.