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.
Examples of different trade‐off shapes. Trade‐offs may be linear (dotted), accelerating (solid) or decelerating (dashed). Non‐linear trade‐offs may be strongly (red) or weakly (blue) accelerating or decelerating as resistance or infectivity increases
