What factor is most responsible for both the very young and the very old being most susceptible to infectious diseases?

Name: What factor is most responsible for both the very young and the very old being most susceptible to infectious diseases?
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Question

Quizplus · Accepted Answer

The host immune system is responsible for fighting off infectious diseases. In very young and very old populations, the immune system may not be fully developed or may be weakened, making these populations more susceptible to infections.

What Factor Is Most Responsible for Both the Very Young