One of the benefits of using growth function such as generalized logistic function in epidemiological modeling is its relatively easy expansion to the multilevel model framework by using the growth function to describe infection trajectories from multiple subjects (countries, cities, states, etc). Such a modeling framework can be also widely called the nonlinear mixed effect model or hierarchical nonlinear model. See the figure above. An example of using the generalized logistic function in Bayesian multilevel model is the Bayesian hierarchical Richards model.