Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The susceptible proportion remaining for a range of first- and second-dose coverages, correlations and age structure parameters. The contours indicate various threshold levels of immunity, where <5% susceptible within the population is generally considered sufficient to maintain elimination and is coloured in blue. The white dashed line indicates where the coverage of each dose is equal.
