A quite similar term, "social distance", also existed for a long time (dating to the 1920s), referring to social-status-distance rather than physical-separation-or-hygiene-in-public-and-social-contects.

The epidemiological term seems to date to 2006 and a US Government planning document.

I've found the term vague, confusing, and inconsistent with established usage.

https://books.google.com/ngrams/graph?content=social%20dista...

There are also many cultures that are renowned for being “socially distant”, even if they’re very small, very compact, and very public transit-reliant.

This seems like globalizing a term that was originally very western- (and particularly English-speaking-) centric.