Have you ever thought about how immunity works? If so, you might have realized that immunity keeps us from becoming sick in different ways. Two types of immunity exist — active and passive:
- Active immunity occurs when our own immune system is responsible for protecting us from a pathogen.
- Passive immunity occurs when we are protected from a pathogen by immunity gained from someone else.
Both of these different types of immunity can be acquired in different ways.
A third category, community immunity, does not involve physical components of the immune system for protection, but is still worth discussion in this capacity.
So, let’s take a closer look at each.
Reviewed by Paul A. Offit, MD on April 22, 2019