Summary

Normal life may return when enough of the population has immunity to Covid-19, limiting further spread. This is known as "herd immunity". (COVID-19 Vaccines and Herd Immunity; Harvard Center for Communicable Disease Dynamics)
Herd immunity may be achieved either through infection and recovery or by vaccination. [1]
Herd immunity also protects those who are unable to be vaccinated, such as newborns and immunocompromised people, because the disease spread within the population is very limited. [1]
To see data for a specific state use the selector on the sidebar.

How much of the population needs immunity?

The herd immunity threshold (HIT) is debated among scientists. The commonly accepted herd immunity threshold for SARS-CoV-2 is 60-80%. [2] [3]
A research group at the University of Oxford estimates the threshold at 10% to 60% when accounting for T cell immunity studies. [2]
Another research group calculates the threshold at 10% to 20% when accounting for diversity in population mixing. [2]
Infections, hospitalizations, and related metrics may decline as population immunity rises, even if the HIT is not reached. [3]

What Is Herd Immunity? | Infectious Diseases | JAMA | JAMA Network
Covid-19: Do many people have pre-existing immunity? | The BMJ
COVID-19 Vaccines and Herd Immunity ; Harvard Center for Communicable Disease Dynamics