Abstract
Some nations have the option of pursuing a policy of complete elimination of covid-19 instead of a policy of “flatttening the curve” so that the load the disease places on medical facilities is bearable. A policy of elimination requires a rather onerous “lockdown”. As the goal of elimination is approached, it is therefore important that there be an informed trade-off between the risk of disease re-emergence and the duration of the “lockdown”. Here it is shown that an important factor in assessing this trade-off, is the distribution of secondary cases, not just the expected value of this distribution, R0. It is shown that a distribution in which “super-spreaders” are more prominent in the epidemiology, allows for an earlier release from “lockdown” with reasonable safety despite some probability of asymptomatic cases. There is some evidence to support such a distribution for covid-19. Analytical calculations and simulations show that once there is only one recognised case in some subregion, release from “lockdown” will be reasonably safe after just one or two further incubation periods.
Competing Interest Statement
The authors have declared no competing interest.
Funding Statement
Paper was prepared as part of my role as an adjunct senior lecturer, with no funding other than being allowed ongoing access to university library resources
Author Declarations
All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.
Yes
All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.
Yes
I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).
Yes
I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.
Yes
Data Availability
There is no relevant data as such - just computer programs developed for this project. The main programs are included as an attachment at the end of the paper. Programs which are near duplicates of each other or that are almost trivial are omitted, but the whole suit of programs used here are available from the author.