COVID-19 Milestone Series
In previous posts I republished early attempts to project fatalities: here and here. In their milestone paper here, Adam T Biggs and Lanny F Littlejohn explain how interventions to protect the public were founded on exaggerated claims about the likely fatalities from the pandemic. One study from Imperial College, London on 16 March 2020 estimated that in the US there could be 2.35M deaths and in the UK, close to 600,000 deaths. To date, total numbers of deaths in these countries have been 769,769 and 144,433 respectively, 32% and 24% respectively of the projections. Will the projected numbers of deaths ever be reached? Nobody can say. For now the estimates appear pessimistic, some might say, grossly inflated.
The societal, economic and psychological burdens resulting from governmental actions to suppress the pandemic will be felt for decades. Whether the governmental actions will ultimately be viewed as justifiable is for future historians to decide. The jury is still out, but I, for one, remain skeptical.
Authors: Adam T Biggs and Lanny F Littlejohn
Open Access Originally Published: March, 2021
Early projections of the COVID-19 pandemic prompted federal governments to action. One critical report, published on March 16, 2020, received international attention when it predicted 2 200 000 deaths in the USA and 510 000 deaths in the UK without some kind of coordinated pandemic response.1 This information became foundational in decisions to implement physical distancing and adherence to other public health measures because it established the upper boundary for any worst-case scenarios.However, the authors derived these projections from best available estimates at the time. The evolving nature of empirical knowledge about COVID-19 provides current estimates with more accurate information than what would have been available merely weeks after first discovery of the virus—plus the benefit of hindsight. For example, asymptomatic transmission has been said to be the Achilles’ heel of public health strategies to control the pandemic,2 and several factors about asymptomatic cases remained uncertain during the early days. The report assumed that asymptomatic individuals were 50% as infectious as symptomatic cases,1 whereas the current US Centers for Disease Control and Prevention (CDC) estimates suggest a 75% infectiousness rate for asymptomatic individuals.3 A more important difference is the infection fatality ratio as originally projected in the Imperial College London (London, UK) report1 versus current estimations. A high ratio of asymptomatic individuals might have inflated the perceived mortality of the disease given the limited testing supplies and attention to symptomatic cases.
|Age 0–19 years||Age 20–49 years||Age 50–69 years||Age >70 years||Total|
|Population||83 267 556||126 429 144||71 216 117||27 832 721||308 745 538|
|Imperial College London report||2733||89 358||725 232||1 532 044||2 349 367|
|CDC estimations||2023||20 482||288 425||1 217 403||1 528 333|
|Seroprevalence||1359||48 638||259 235||1 070 381||1 379 612|
|Population||15 098 000||26 193 000||14 533 000||7 359 000||63 183 000|
|Imperial College London report||493||18 744||159 069||402 318||580 624|
|CDC estimations||367||4243||58 859||321 883||385 351|
|Seroprevalence||250||10 184||56 653||279 548||346 637|
Data are from the initial Imperial College London report1 and two more recent parameter estimations from the CDC3 and a retrospective study with data from 45 countries (seroprevalence).4 CDC=US Centers for Disease Control and Prevention.
This simplified assessment arrives at a comparable approximation of the original report—2 349 367 projected deaths in the USA and 580 624 deaths in the UK. Applying age-adjusted infection fatality ratio rates to the census population values reveals a striking difference from CDC estimates and seroprevalence reporting. CDC estimates place total deaths at 1 528 333 in the USA and 385 351 deaths in the UK, whereas seroprevalence estimates total deaths at 1 379 612 in the USA and 346 637 deaths in the UK. For the US estimates, the differences produce a 54–70% overestimation of approximately 1 million deaths. For the UK estimates, the differences produce a 51–68% overestimation of approximately 200 000 deaths.Such overestimations remind us of several lessons learned over the course of the pandemic. First, the initial projections were never going to be 100% accurate with a novel coronavirus. Initial projections built worst-case scenarios that would never happen as a means of spurring leadership into action. This upper boundary of possibility then demonstrates a functional value of modelling efforts for unmitigated pandemic progression. Second, asymptomatic cases inflated perceived mortality ratios in addition to complicating any containment challenges. Third, consensus predictions underscore the value of public health coordination—especially early in a novel outbreak. When information is scarce, information sharing from multiple sources becomes crucial to attaining the clearest prediction possible. Last, in democracies, these public health crises will be politicised, and it is incumbent upon guardians of the public trust in health-care institutions and services to remain apolitical—to remain focused on scientific knowledge and the needs of public health, just as the US Department of Defense remains apolitical and focused on the needs of national defence.Ultimately, the relative value of mask wearing and physical distancing, and the economic consequences of lockdowns will be analysed retrospectively. These evaluations will use worst-case scenarios of unmitigated progression as the measuring stick to describe the merit of different public health interventions. Still, initial projections were commendable efforts that brought about public action despite more than 2 million deaths in the USA and more than 500 000 deaths in the UK being a significant overestimation.
We declare no competing interests. The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the US Department of the Navy, the US Department of Defense, or the US Government. The authors are military service members or employees of the US Government. This work was prepared as part of their official duties. Title 17 U.S.C. §105 provides that ‘Copyright protection under this title is not available for any work of the United States Government.’ Title 17 U.S.C. §101 defines a US Government work as a work prepared by a military service member or employee of the US Government as part of that person’s official duties.
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