The Reproduction Number

Generations of infection

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• $R_0$: the average number infected by one case in a fully susceptible population.
• New cases in generation $n$: $R_0^n$.
• Small differences in R make enormous differences over generations.

Steps

1. R
2. Five generations
3. Comparing diseases
4. A thousand cases
5. From generations to days
6. Is R fixed?