What is the mathematical formula for $R_0$ and what does each variable represent?

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1 Answer 1


$$R_0 ∝ \left(\frac{\text{infection}}{\text{contact}}\right) · \left(\frac{\text{contact}}{\text{time}}\right) · \left(\frac{\text{time}}{\text{infection}}\right)$$

More specifically:

$$R_0 = τ · \bar{c} · d \quad \quad (1)$$

where $τ$ is the transmissibility (i.e., probability of infection given contact between a susceptible and infected individual), $\bar{c}$ is the average rate of contact between susceptible and infected individuals, and $d$ is the duration of infectiousness.

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