CDC Influenza National Pandemic Strategy Documents

Influenza and COVID-19 aren't related, but the overall infection math works similarly. They are most closely modeled by a differential equation that has a carrying capacity that moves based on many factors. Their main commonality is they are both highly infectious.

Different parts of the world are at different phases of the situation. The US is currently at the recognition phase, and it's difficult to tell, without additional cases, the estimated time until acceleration. [0]

0. https://www.cdc.gov/flu/pandemic-resources/pdf/mmwr-rr6306.p... p. 4