IMMUNOLOGY

Detailed explanation-1: -Once B cells and T cells are formed, a few of those cells will multiply and provide “memory” for your immune system. This allows your immune system to respond faster and more efficiently the next time you are exposed to the same antigen.

Detailed explanation-2: -Another study6 in Qatar suggests that if the virus doesn’t change, infection-based immunity against reinfection can last up to three years. But that immunity can fade faster if the virus mutates. The authors studied data from unvaccinated people who were infected with a pre-Omicron variant.

Detailed explanation-3: -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-4: -The main feature of the innate immune system is to respond quickly, which can lead to inflammation and fever. It does not recognize specific strains of bacteria or viruses; it attacks broadly, which is why it is unable to get rid of all pathogens.

Detailed explanation-5: -One reason the adaptive immune response is delayed is because it takes time for naïve B and T cells with the appropriate antigen specificities to be identified and activated. Upon reinfection, this step is skipped, and the result is a more rapid production of immune defenses.

Detailed explanation-6: -Adaptive immunity is the immunity that we are not born with and must be developed over our lifetime. Under this category, we can further split it into active and passive immunity.