Big cities have encouraged "cliff dwelling" for a long time. Now the push to affordable housing further encourages that. I would say any study of epidemiology shows high densities contribute to infectious disease spread. This never was a topic for seasonal flu deaths - it was a basic public health regimen to limit the spread. As big pharma eventually finds a preventative vaccine, the density concern will pass. People have been taught to rely on the benevolence of big city democrat giveaways to adopt a new living standard. My .02
