Why does passive immunity last long?

Passive immunity lasts longer because it involves the transfer of antibodies from one individual to another, providing immediate protection without the need for the recipient's immune system to produce its own antibodies. These antibodies can remain in the bloodstream for weeks to months, depending on their type and the individual's metabolism. However, since passive immunity does not stimulate the recipient's immune system to create a memory response, it does not provide long-term immunity like active immunity. Thus, while passive immunity offers short-term protection, its duration can still be significant compared to other forms of immediate defense.