Question

why is the adaptive immune response to an initial infection slower than the innate response

Answer 1

Innate immunity is a non-specific defence mechanism that works against all pathogen and comes to play their role as quickly as pathogens enters into the body. The mechanism by which innate immunity works physical barriers like skin, chemicals in blood and immune system cells like basophil, dendritic cells, eosinophils, NK cells, neutrophils, macrophages and monocyte. These cells are always present in the body and becomes activated as soon as a pathogen enters into the body.

On the other hand adaptive immunity is slow and specific for particular antigen but protects for longer periods. Adaptive immunity is slow because for the activation of B and T cells, the major cell types of adaptive immunity is dependent on the cells of innate immunity. Cells of innate immunity like dendritic cells first process the antigen and then express this antigen on the surface for the recognition by T cells. Once activated T cells causes activation and proliferation of B cells.

So adaptive immunity is slow er than innate immunity because it requires information from innate immunity to function.