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In order for vaccines to protect a population from a pathogen:
A. Most of the population must be vaccinated
B. No one in the population can have the disease
C. Only a few people need to be vaccinated
D. Everyone in the population must have the disease

Respuesta :

Hi !

In order for vaccines to protect a population from a pathogen:

A. Most of the population must be vaccinated

The answer is A! It’s called herd immunisation (like a herd of sheep, a herd of immunised people). Because some people may have weaker immune systems so they can’t have the vaccine and so they are relying on other people to be vaccined and not catch the virus to pass it onto them.