What does "herd immunity" allow within a population?

Herd immunity is a critical concept in public health that refers to the protection provided to a population when a sufficiently high proportion of individuals are immune to a contagious disease, either through vaccination or past infection. When this immunity threshold is met, the spread of the disease is significantly limited, as there are fewer opportunities for the pathogen to circulate. This means that even individuals who are not immune (such as those who cannot be vaccinated for medical reasons) are indirectly protected because the likelihood of coming into contact with an infected person is reduced.

This concept is essential in controlling outbreaks and maintaining overall public health within a community. While herd immunity can contribute to various outcomes, such as encouraging higher vaccination rates or possibly reducing healthcare costs by preventing disease outbreaks, its primary function is the resistance to the spread of contagious diseases, safeguarding both the immunized and non-immunized members of the population.