What is the second type of immunity in addition to innate immunity?

The second type of immunity, in addition to innate immunity, is adaptive immunity. Adaptive immunity refers to the body's ability to recognize and specifically respond to pathogens that it has encountered before. This type of immunity develops over time and involves the activation of lymphocytes, such as B cells and T cells, which play crucial roles in identifying and attacking specific antigens.

Adaptive immunity is characterized by its memory function, which allows the immune system to respond more rapidly and effectively upon subsequent exposures to the same pathogen. This is in contrast to innate immunity, which provides the first line of defense through physical barriers and general immune responses but does not have the ability to remember specific pathogens.

Natural, passive, and functional immunity can be seen as different aspects or mechanisms of immunity, but they are not the primary type recognized as the counterpart to innate immunity. Natural immunity generally alludes to the immunity obtained through natural exposures, while passive immunity refers to the transfer of antibodies from one individual to another. Functional immunity is less defined and not universally recognized as a primary category of immunity like innate and adaptive are.