Yes, Social Distancing Works!

Many experts recommend social distancing as a way to control the spread of coronavirus. But does it work? YES!

See this example from the 1918 flu pandemic. It compares the mortality rates in Philadelphia and Saint Louis. Philadelphia waited 16 days after the 1st case to implement social distancing measures. St. Louis waited just two days to close schools and ban public gatherings . St. Louis had a much lower death rate overall and avoided a big spike in cases.

  Figure: Excess pneumonia and influenza mortality over 1913-1917 baseline in Philadelphia and       St. Louis, September 8 – December 28, 1918. Source:  https://www.pnas.org/content/104/18/7582 .
Figure: Excess pneumonia and influenza mortality over 1913-1917 baseline in Philadelphia and St. Louis, September 8 – December 28, 1918. Source: https://www.pnas.org/content/104/18/7582 .

Social distancing has also been effective in China during the current COVID-19 pandemic. After the epidemic in Wuhan, other Chinese cities implemented strict social distancing measures, including closing schools. These cities have so far faced far fewer cases than Wuhan.

But how does it work? Social distancing reduces the burden of the epidemic in three ways:

(1)   It reduces the transmission rate, resulting in a lower total number of infections.

(2)   It delays some infections. This gives us more time to learn about how to care for patients with the disease, and to develop drugs to treat it.

(3)   It lowers the peak of the epidemic, helping to limit the total number of cases at any point in time. This is important because the capacity of the health system (including things as simple as the number hospital beds) is limited.

If you want a visual of what this actually looks like, check out these video simulations.

The evidence is there. If you’re able to, now is the time to get comfortable, turn on Netflix, and protect yourself and your community.