Table 2.

Public health responses to the COVID-19 epidemic (from [3,11,12]).

	Scenarios from Walker et al. [3]	Scenarios from Pearson et al. [11]	Scenarios from Cabore et al. [12]
Unmitigated epidemic (most severe)*	No action is taken and R0 is 2.3.	No action is taken and R0 is 2.7.	No action is taken and R0 is 1.7 overall (range of 1.5–1.8, depending on country).
Social distancing	Population-level social distancing, i.e. the maximum reduction in the final scale of the epidemic that can be achieved through a uniform reduction in the rate at which individuals contact one another, short of suppression (for South Africa, e.g., this equates to a 37–48% reduction in social contacts).	Population-level social distancing, i.e. the maximum reduction in the final scale of the epidemic that can be achieved through a uniform reduction in the rate at which individuals contact one another, short of suppression (for all countries, this equates to a 20% reduction in social contacts).	Not modelled.
Enhanced social distancing interventions (least severe)	Population-level social distancing as above, with individuals aged 70 years old and older additionally reducing their social contact rates by 60%.	Shielding of 60% of those aged 60 years old and older with a 60% reduction in transmission in addition to a 20% reduction in contacts outside the household and a 25% reduction in transmission from symptomatic individuals.	Not modelled.

^⁎This is provided as a comparator ‘Reasonable Worst-Case Scenario’: it is considered very unlikely because, in reality, actions being taken to mitigate the epidemic would have an effect.