Doctors do not administer vaccinations to people who are too sick. Which best explains why?

A vaccine works by exposing the immune system to a harmless or weakened form of a pathogen so it can build protection. Someone who is seriously ill may have an immune system that is already struggling and may not respond to the vaccine as effectively. Therefore, D, that the white blood cells may not efficiently handle the weakened or dead pathogen, is the best choice.

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