Linking the The Imperial College paper here (which a lot of people have referenced lately) that addresses these two approaches: (a) mitigation, which focuses on slowing but not necessarily stopping epidemic spread –reducing peak healthcare demand while protecting those most at risk of severe disease from infection, and (b) suppression, which aims to reverse epidemic growth, reducing case numbers to low levels and maintaining that situation indefinitely. (https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf)
The biggest issue with the suppression strategy is the time required for the lockdown - until R reaches low enough levels that eliminate human-to-human transmission, or until a vaccine is available. Estimated 12-18 months with a r0 of 2.4.
In fact the more successful a strategy is at temporary suppression (China), the larger the later epidemic if the lockdown is lifted prematurely—due to lesser build-up of herd immunity (Figure 3, “post-September 2020”).
Mitigation: “In the most effective mitigation strategy examined, which leads to a single, relatively short epidemic, the surge limits for both general ward and ICU beds would be exceeded by at least 8-fold under the more optimistic scenario for critical care requirements that we examined. In addition, even if all patients were able to be treated, we predict there would still be in the order of 250,000 deaths in GB, and 1.1-1.2 million in the US.”
Yes you are correct, succinctly addressed here ” They ignore standard Contact Tracing [2] allowing isolation of infected prior to symptoms. They also ignore door-to-door monitoring to identify cases with symptoms [3]. Their conclusions that there will be resurgent outbreaks are wrong. After a few weeks of lockdown almost all infectious people are identified and their contacts are isolated prior to symptoms and cannot infect others [4]. ” https://necsi.edu/review-of-ferguson-et-al-impact-of-non-pharmaceutical-interventions