The ethics and science behind the COVID-19 social distancing interventions

Bottom Line:

The scientific and ethical basis for quarantine and social distancing are multifaceted, and their effectiveness depends on the credibility of  public health authorities, as well as the transparency of political leaders and institutions.


Lewnard, J.A. & Nathan, C.L. Scientific and ethical basis for social-distancing interventions against COVID-19. The Lancet. Infectious diseases (2020).

Date Published:

23 March 2020


While there are currently no effective pharmaceutical interventions against COVID-19, the logical strategy is to prevent any form of close-proximity contact between infected individuals and susceptible individuals. This is supported by robust scientific evidence. In a study published in the The Lancet Infectious Diseases, researchers looked at the effectiveness of social distancing on COVID-19 spread and burden in Singapore. They found that although Singapore was one of the first countries affected, they have so far managed to successfully slow community spread. China responded by implementing extreme measures such as closure of workplaces, roads, mandatory quarantine, and mass digital surveillance. The researchers further developed mathematical modelling using the Singaporean population to assess the effect of combined intervention (quarantine, school closure, and workplace distancing) on the spread of COVID-19 infections under three different infectivity scenarios. Results showed that combined intervention can substantially lower the number of infections, with the estimated median number of infections reduced by up to 99.3%. However, this value is calculated with the assumption that there is high compliance among the general population, which may not always be the case. Although robust scientific evidence supports these interventions, the ethics of social distancing should also be considered. For example, leaders should be mindful of enacting quarantine and social-distancing policies that minimize bias against certain populations. Such interventions may increase the burden of individuals with lower income and job instability, and may often end up affecting the most vulnerable groups. Therefore, special attention should be given to the elderly, the homeless, disabled individuals, and immigrants without status. 

Summary by: Winston Li