If infections are spread by person-to-person contact, what percentage of the population will be protected against herd immunity if people are not vaccinated?
A) 66%
B) 25%
C) 10%
D) 100%
E) 40%

Question

Quizplus · Accepted Answer

The percentage of the population that needs to be protected to achieve herd immunity varies depending on the disease, but for many infections spread by person-to-person contact, around 70% to 90% of the population needs to be immune. Therefore, none of the options precisely match this range, but 66% (A) is closest to the lower end of the typical range needed for herd immunity.

If Infections Are Spread by Person-To-Person Contact, What Percentage of the Population