Called the R-naught, or basic reproductive number, the model predicts the average number of susceptible people who will be infected by one infectious person.

The basic reproduction number, R₀, holds the key to how large that proportion is. The higher the basic reproduction number, the higher the immune proportion of the population needs to be.

R (t), the effective reproductive number, is an important parameter in this model as it reflects the change in R0 (the basic reproduction number) with time and mitigation strategies.

Scientists used a SEIR model and a Bayesian inference framework to estimate the basic reproduction number of COVID-19 across Africa.