Community • 13 Apr 2020

Social Distancing & Lessons From The Past

By uci_admin

Research Focus: Social Distancing and Lessons from the Past

By Jacob Hwang, ND

Social distancing has become a regular part of our normal routine. It may seem mundane on a daily basis, but it is the most effective way to reduce new infections and protect others. Social distancing or physical distancing is simply a community effort to reduce physical distance and meeting in socially dense settings (Wilder-Smith & Freedman, 2020). This public health intervention was observed and documented in the United Kingdom as a reactive human behavioral response during the 1918 influenza pandemic (Yu, Lin, Chiu, & He, 2017). This measure was also put into action by American cities during the same pandemic, which revealed how physical distancing and isolation influenced the transmission of disease. During the 2003 SARS pandemic, social distancing was implemented by the World Health Organization in addition to other interventions, which helped contain the SARS-CoV (Bell, 2004). The efficacy of social distancing was demonstrated again during the 2009 H1N1 influenza pandemic as shown by the 23% median reduction of transmission in the general population (Ahmed, Zviedrite, & Uzicanin, 2018). It is important to understand that social distancing is not only helpful for reducing transmission, but also for delaying the peak infection rate.

To further understand the impact of social distancing on pandemics, the R0 (R naught) is a useful measure. Epidemiologists and public health officials have yet to conclude the definitive R0 for the SARS-CoV-2, the virus responsible for the current COVID-19 pandemic. The R0 is known as the basic reproduction number and helps describe the contagiousness or transmissibility of an infectious agent in a vulnerable population without established immunity. In layman’s terms, if the R0 is 1, then it means that one infected person can lead to one new infection. If the R0 is 2, then it means that one infected person can lead to two new infections. The 2003 SARS-CoV had a reported R0 of 3, while the current SARS-CoV-2 is still being estimated between 2.0-2.5 (Wu, D., Wu, T., Liu, & Yang 2020). Social distancing is less effective when the R0 > 6 due to the virus being too contagious, which explains why it was helpful for controlling previous infectious outbreaks. Looking back on history to learn from past successes and failures, it is clear that social distancing is a key strategy for containing the COVID-19 pandemic.


  1. Ahmed F, Zviedrite N, Uzicanin A. Effectiveness of workplace social distancingmeasures in reducing influenza transmission: a systematic review. BMC PublicHealth. 2018 Apr 18;18(1):518. doi: 10.1186/s12889-018-5446-1.
  2. Bell DM; World Health Organization Working Group on International and Community Transmission of SARS. Public health interventions and SARS spread, 2003. Emerg Infect Dis. 2004 Nov;10(11):1900-6.
  3. Wilder-Smith A, Freedman DO. Isolation, quarantine, social distancing and community containment: pivotal role for old-style public health measures in the novel coronavirus (2019-nCoV) outbreak. J Travel Med. 2020 Mar 13;27(2). pii: taaa020. doi: 10.1093/jtm/taaa020.
  4. Wu D, Wu T, Liu Q, Yang Z. The SARS-CoV-2 outbreak: what we know. Int J Infect Dis. 2020 Mar 11. pii: S1201-9712(20)30123-5. doi: 10.1016/j.ijid.2020.03.004. [Epub ahead of print] Review.
  5. Yu D, Lin Q, Chiu AP, He D. Effects of reactive social distancing on the 1918 influenza pandemic. PLoS One. 2017 Jul 12;12(7):e0180545. doi: 10.1371/journal.pone.0180545. eCollection 2017.
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