The Mitigation Strategy doesn’t try to contain the epidemic, just flatten the curve a bit. Meanwhile, the Suppression Strategy tries to apply heavy measures to quickly get the epidemic under control. Specifically:
- Go hard right now. Order heavy social distancing. Get this thing under control.
- Then, release the measures, so that people can gradually get back their freedoms and something approaching normal social and economic life can resume.
The benefit of suppression is that it would provide us time to develop new testing methods, build capacity in regards to equipment and get things in order. Overall this would provide a number of benefits, such as:
- Fewer total cases of Coronavirus
- Immediate relief for the healthcare system and the humans who run it
- Reduction in fatality rate
- Reduction in collateral damage
- Ability for infected, isolated and quarantined healthcare workers to get better and back to work. In Italy, healthcare workers represent 8% of all contagions.
Pueyo suggests that a suppression strategy can be understood as a hammer and a dance.
During the Hammer period, politicians want to lower R as much as possible, through measures that remain tolerable for the population. In Hubei, they went all the way to 0.32. We might not need that: maybe just to 0.5 or 0.6.
But during the Dance of the R period, they want to hover as close to 1 as possible, while staying below it over the long term term. That prevents a new outbreak, while eliminating the most drastic measures.
What this means is that, whether leaders realize it or not, what they’re doing is:
- List all the measures they can take to reduce R
- Get a sense of the benefit of applying them: the reduction in R
- Get a sense of their cost: the economic, social, and ethical cost.
- Stack-rank the initiatives based on their cost-benefit
- Pick the ones that give the biggest R reduction up till 1, for the lowest cost.
A lot of this is elaborated on further in the Imperial College’s report Impact of non-pharmaceutical interventions (NPIs) to reduce COVID19 mortality and healthcare demand.
We show that in the UK and US context, suppression will minimally require a combination of social distancing of the entire population, home isolation of cases and household quarantine of their family members. This may need to be supplemented by school and university closures, though it should be recognised that such closures may have negative impacts on health systems due to increased absenteeism. The major challenge of suppression is that this type of intensive intervention package – or something equivalently effective at reducing transmission – will need to be maintained until a vaccine becomes available (potentially 18 months or more) – given that we predict that transmission will quickly rebound if interventions are relaxed. We show that intermittent social distancing – triggered by trends in disease surveillance – may allow interventions to be relaxed temporarily in relative short time windows, but measures will need to be reintroduced if or when case numbers rebound. Last, while experience in China and now South Korea show that suppression is possible in the short term, it remains to be seen whether it is possible long-term, and whether the social and economic costs of the interventions adopted thus far can be reduced.
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