Author Archives: niclewis

When does government intervention make sense for COVID-19?

By Nic Lewis

Introduction

I showed in my last article that inhomogeneity within a population in the susceptibility and infectivity of individuals would reduce the herd immunity threshold, in my view probably very substantially, and that evidence from Stockholm County appeared to support that view. In this article I will first provide other evidence pointing to such population inhomogeneity being very considerable. I will then go on to consider how the overshoot of infections beyond the herd immunity threshold could be reduced. Continue reading

Why herd immunity to COVID-19 is reached much earlier than thought

By Nic Lewis

Introduction

A study published in March by the COVID-19 Response Team from Imperial College (Ferguson20[1]) appears to have been largely responsible for driving government actions in the UK and, to a fair extent, in the US and some other countries. Until that report came out, the strategy of the UK government, at least, seems to have been to rely on the build up of ‘herd immunity’ to slow the growth of the epidemic and eventually cause it to peter out. Continue reading

A sensible COVID-19 exit strategy for the UK

By Nic Lewis

The current approach

A study by the COVID-19 Response Team from Imperial College (Ferguson et al. 2020[i]) appears to be largely responsible for driving UK government policy actions. The lockdown imposed in the UK appears, unsurprisingly, to have slowed the growth of COVID-19 infections, and may well soon lead to total active cases declining. However, it comes at huge economic and social costs, and substantial COVID-19-unrelated health costs.

Worse, the lockdown is merely a holding strategy, which offers no long term solution to the COVID-19 problem. The eventual total number of deaths for COVID-19 are not reduced relative to any less restrictive policy that likewise avoided the health system being overwhelmed. Deaths are merely spread over a longer period, assuming that eventually restrictions are lifted and people’s lives return to normal. Continue reading

Imperial College UK COVID-19 numbers don’t seem to add up

By Nic Lewis

Introduction and summary

A study published two weeks ago by the COVID-19 Response Team from Imperial College (Ferguson20[1]) appears to be largely responsible for driving UK government policy actions. The study is not peer reviewed; indeed, it seems not to have been externally reviewed at all. Moreover, the computer code used to produce the estimates in the study – which on Ferguson’s own admission is old, unverified and documented inadequately, if at all – has still not been published. That, in my view, shows a worrying approach to a matter of vital public concern.

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COVID-19: Updated data implies that UK modelling hugely overestimates the expected death rates from infection

By Nic Lewis

Introduction

There has been much media coverage about the danger to life posed by the COVID-19 coronavirus pandemic. While it is clearly a serious threat, one should consider whether the best evidence supports the current degree of panic and hence government policy. Much of the concern in the UK resulted from a non-peer reviewed study published by the COVID-19 Response Team from Imperial College (Ferguson et al 2020[1]). In this article, I examine whether data from the Diamond Princess cruise ship – arguably the most useful data set available – support the fatality rate assumptions underlying the Imperial study. I find that it does not do so. The likely fatality rates for age groups from 60 upwards, which account for the vast bulk of projected deaths, appear to be much lower than those in the Ferguson et al. study. Continue reading

Comment by Cowtan & Jacobs on Lewis & Curry 2018 and Reply: Part 2

By Nic Lewis

In an earlier article here I discussed a Comment on Lewis and Curry 2018 (LC18) by Kevin Cowtan and Peter Jacobs (CJ20), and a Reply from myself and Judith Curry recently published by Journal of Climate (copy available here). I wrote that I would defer dealing with the differences between observed and CMIP5 model-simulated historical warming, which formed the basis of CJ20’s numerical analysis, until a subsequent article. I now do so. Continue reading

Comment by Cowtan & Jacobs on Lewis & Curry 2018 and Reply: Part 1

By Nic Lewis

A comment on LC18 (recent paper by Lewis and Curry on climate sensitivity)  by Cowtan and Jacobs has been published, along with our response.

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