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Lockdowns as Public Health Policy
World Economic Forum Campaign for Lockdowns
WEF- Why lockdowns can halt the spread of COVID-19 21 Mar 2020 by Samantha Sault - Writer, Washington DC and Geneva
(selected highlights.. see link for Neil Ferguson charts) The UK, US, EU and many other countries are currently in some degree of “lockdown,” with restaurants and bars, shops, schools and gyms closed, and citizens required, or at least strongly encouraged, to stay home to avoid catching or spreading COVID-19, the respiratory illness caused by the novel coronavirus.
Researchers are well on their way to discovering vaccines and treatments for the virus, but even in a best-case scenario, these are likely to be 12-18 months away.
Until then, extreme social distancing is pretty much the only intervention available to help individuals stay healthy, and to break the chain of transmission - giving more vulnerable populations a fighting chance of surviving this pandemic.
But how exactly does a lockdown work? And why is it important for even younger and healthier people, who face a lower risk of severe illness, to remain in their homes as much as possible?
The goal; R<1
The purpose of a lockdown, explains a new study from the Imperial College London COVID-19 Response Team, is to reduce reproduction – in other words, to reduce the number of people each confirmed case infects. 1)
The goal is to keep reproduction, or “R,” below one (R<1) – with each case infecting fewer than one other person, on average.
The authors of the study say there are two routes to try to get there;
Mitigation, “slowing but not necessarily stopping epidemic spread – reducing peak healthcare demand while protecting those most at risk of severe disease from infection.” This is done by isolating suspected cases and their households, and social distancing the elderly and people at highest risk of serious illness.
Suppression, or basically, lockdown, which “aims to reverse epidemic growth, reducing case numbers to low levels” by social distancing the entire population “indefinitely” and closing schools and universities.
The study’s models show that, painful as lockdown may be for many of us, it works.
Without any lockdown or social distancing measures, we can expect peak mortality in approximately three months. In this scenario, 81% of the UK and US populations would be infected, with 510,000 dying in the UK and 2.2 million dying in the US….
So, have the lockdowns worked?
Starting 23 January 2020, the Chinese government locked down Hubei Province, including Wuhan, the city of 11 million where the outbreak started. They halted transportation in and out and barred tens of millions of people from working or going to school and closed all shops except those selling food or medicine. In some areas, residents were even forced to limit trips to the store, or order supplies for delivery.
This unprecedented lockdown of tens of millions of people was considered a “vast experiment” – but it may have worked. Following the lockdown, cases began to slow. On 19 March, China’s National Health Commission reported no new confirmed infections in Hubei.2)
Historical Evidence
Influenza
Imperial College COVID-19 Response Team
- 16 March 2020 Imperial College COVID-19 Response Team
- DOI; https://doi.org/10.25561/77482 Page 1 of 20
- Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-
- 19 mortality and healthcare demand
- Neil M Ferguson, Daniel Laydon, Gemma Nedjati-Gilani, Natsuko Imai, Kylie Ainslie, Marc Baguelin,
- Sangeeta Bhatia, Adhiratha Boonyasiri, Zulma Cucunubá, Gina Cuomo-Dannenburg, Amy Dighe, Ilaria
- Dorigatti, Han Fu, Katy Gaythorpe, Will Green, Arran Hamlet, Wes Hinsley, Lucy C Okell, Sabine van
- Elsland, Hayley Thompson, Robert Verity, Erik Volz, Haowei Wang, Yuanrong Wang, Patrick GT Walker,
- Caroline Walters, Peter Winskill, Charles Whittaker, Christl A Donnelly, Steven Riley, Azra C Ghani.
- On behalf of the Imperial College COVID-19 Response Team
- WHO Collaborating Centre for Infectious Disease Modelling
- MRC Centre for Global Infectious Disease Analysis
- Abdul Latif Jameel Institute for Disease and Emergency Analytics
- Imperial College London
- Correspondence; neil.ferguson@imperial.ac.uk
“Disease Progression and Healthcare Demands p. 5 Analyses of data from China as well as data from those returning on repatriation flights suggest that 40-50% of infections were not identified as cases12. This may include asymptomatic infections, mild disease and a level of under-ascertainment. We therefore assume that two-thirds of cases are sufficiently symptomatic to self-isolate (if required by policy) within 1 day of symptom onset, and a mean delay from onset of symptoms to hospitalisation of 5 days.”
Results p. 6 In the (unlikely) absence of any control measures or spontaneous changes in individual behaviour, we would expect a peak in mortality (daily deaths) to occur after approximately 3 months (Figure 1A). In such scenarios, given an estimated R0 of 2.4, we predict 81% of the GB and US populations would be infected over the course of the epidemic. Epidemic timings are approximate given the limitations of surveillance data in both countries: The epidemic is predicted to be broader in the US than in GB and to peak slightly later. This is due to the larger geographic scale of the US, resulting in more distinct localised epidemics across states (Figure 1B) than seen across GB…. we would predict approximately 510,000 deaths in GB and 2.2 million in the US, not accounting for the potential negative effects of health systems being overwhelmed on mortality.3)