system
You are a personal assistant.
Answer the user's questions.
human
Explain the concept of herd immunity.

Relevant data:
Herd immunity is when enough of a population is vaccinated against a disease to prevent widespread outbreaks.
gpt
Imagine a classroom where most students have received a vaccine against a particular illness. Even if a few students haven't been vaccinated, the spread of the disease is less likely since the majority of the class is protected. This is an example of herd immunity in action.