The effectiveness of three social-distancing strategies designed to limit the spread of COVID-19 post lockdown are evaluated in a series of simulations reported in Nature Human Behaviour.
Social distancing has been a key policy in attempting to reduce the spread of COVID-19 by maintaining physical distance and reducing social interactions. However, complete or near-complete lockdown can have adverse social, psychological and economic consequences.
Per Block and colleagues propose that limiting the spread of the virus can be achieved by managing the network of people’s interpersonal contacts. In a series of computer simulations, the authors evaluated the impact three social-distancing strategies may have on the spread of COVID-19: contact with only similar people (for example, determined by geography or membership in the same organization); strengthening contact within communities (for instance, where people only meet with friends when they have many friends in common); and repeatedly interacting with the same people in ‘bubbles’ (restricting interactions to a specific group of people).
The authors found that all three strategies slow the spread of the virus compared to no intervention or non-strategic social distancing (where individuals reduce interactions, but choose randomly among their contacts), with social bubbles proving to be the most effective. However, as most people would require the ability to interact across multiple social circles (such as workplace and extended family), the authors tested the effectiveness of combinations of their strategies as well. They found that combined strategies (either combining two of the approaches or all three) were as effective as single strategies and worked better than non-strategic contact. When modelling the strategies for 500 to 4,000 people, the authors found no variation in the relative effectiveness.
They conclude that a social-network based strategy can enhance the effectiveness of social distancing and may mitigate the negative effects of social isolation.
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