Initial success for COVID-19 social distancing in China

Relaxing social distancing in China shows initial success, suggests early analysis.

** UPDATE (28-04-2020): This research (Report 11) has now been peer reviewed and published in Wellcome Open Research. **

This is the latest research from the WHO Collaborating Centre for Infectious Disease Modelling within the MRC Centre for Global Infectious Disease Analysis (MRC GIDA) and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA) at Imperial College London.

Our report shows initial evidence that...strict measures may be relaxed, and economic activities resumed without the recurrence of local transmission Dr Kylie Ainslie Report author

Since the emergence of the new coronavirus (COVID-19) in December 2019, the team have adopted a policy of immediately sharing research findings on the developing pandemic. 

This current report, the 11th in the series, estimates transmissibility from reported cases and compares those estimates with daily data on within-city movement, as a proxy for economic activity (provided by Exante Data, NY).

For the first time since the outbreak began, in China there have been no new confirmed cases caused by local transmission reported for five consecutive days up to 23 March 2020. This is an indication that the social distancing measures enacted in China have led to control of COVID-19 in the country. At the peak of the outbreak in China (early February), there were between 2,000 and 4,000 new confirmed cases per day.

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Social-distancing interventions have also impacted economic productivity in China, and the ability of the Chinese economy to resume without restarting the epidemic is not yet clear.

Strict measures may be relaxed

Dr Kylie Ainslie, co-author of the report from the MRC GIDA and J-IDEA at Imperial College London, explained: “Our report shows initial evidence that, after successful containment of COVID-19 with strict social distancing measures, those strict measures may be relaxed, and economic activities resumed without the recurrence of local transmission.” 

Our analysis indicates that China has made a promising start in rebooting their economy whilst controlling the spread of COVID-19 Dr Caroline Walters Report author

Initially, within-city movement and transmission were very strongly correlated in the five provinces most affected by the epidemic and Beijing.

However, that correlation is no longer apparent even though within-city movement has started to increase. A similar analysis for Hong Kong shows that intermediate levels of local activity can be maintained while avoiding a large outbreak.

Dr Caroline Walters, report co-author, from MRC GIDA and J-IDEA, explained: “Our analysis indicates that China has made a promising start in rebooting their economy whilst controlling the spread of COVID-19.”

Dr Han Fu, report co-author, from MRC GIDA and J-IDEA, explained: “By investigating the relationship between within-city movement and the estimated reproduction number, we observed that the relaxation of strict social distancing measures and resumption of economic activities, so far, has not resulted in frequent local transmission of COVID-19 in China.”

Analysis provides hope for countries in lockdown

The COVID-19 epidemic was declared a Global Pandemic by WHO on 11 March 2020. As of 20 March 2020, over 254,000 cases and 10,000 deaths had been reported worldwide.

After containment, a carefully managed and monitored relaxation of effective large-scale lockdowns may be possible Professor Christl Donnelly Report author

The outbreak began in the Chinese city of Wuhan in December 2019. In response to the fast-growing epidemic, China imposed strict social distancing in Wuhan on 23 January 2020 followed closely by similar measures in other provinces.

Professor Christl Donnelly, Associate Director of the MRC GIDA, added: "At this difficult time, these results suggest that, after containment, a carefully managed and monitored relaxation of effective large-scale lockdowns may be possible even before an effective vaccine is available.”

This analysis provides some hope for countries currently in various levels of lockdown that once case numbers are brought to low levels, it might be possible to relax social distancing Professor Neil Ferguson Report author

Professor Neil Ferguson, Director of J-IDEA at Imperial College London and MRC GIDA explained: “This analysis provides some hope for countries currently in various levels of lockdown that once case numbers are brought to low levels, it might be possible to relax social distancing - provided equal measures to limit the risk of the resurgence of transmission are introduced. Such suppression maintenance policies will likely need to rely on rapid and ubiquitous testing and rigorous case and contact isolation policies.”

Professor Steven Riley, report co-author from the MRC GIDA and J-IDEA at Imperial, said:“Although we do not know what will happen next in China, this report shows that very stringent social distancing can be relaxed after containment has been achieved without transmission returning in the short term.”

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This article is adapted from a press release from the MRC Centre for Global Infectious Disease Analysis

The full report is available on the MRC Centre for Global Infectious Disease Analysis webpage.