Despite the force and weight with which it has dropped on the United States, the coronavirus pandemic isn’t a meteor.

It is a mistake to treat it as such, unmoving and unyielding.

Instead, it has to be approached as the wild animal that it is — constantly moving and changing.

Let’s look at how that’s happening.

Allegheny County was one of the early red spots in the covid-19 map of Pennsylvania. That made sense. Most of those cases were in city centers, like Pittsburgh and Philadelphia.

That contributed to Allegheny County Health Department’s decision to enact some additional protocols above and beyond Gov. Tom Wolf’s restrictions, like tighter numbers for gatherings.

Less densely populated counties might view everything the state was doing in response to covid-19 as overreaction. Some places went months without a positive test. Today Greene, Venango and Warren counties still have just one death apiece, according to state numbers.

But what was easy math — more people, more diagnoses — is changing.

On Monday, Allegheny County reported 46 new cases, once again taking the No. 2 spot behind Philadelphia.

But the bronze went to Westmoreland County with 45 new cases, in a population about one-third of Allegheny County’s.

How is this happening? According to officials, it isn’t the recent nursing home outbreak. It’s being driven by community spread.

And that is what shows how the pandemic is shifting.

It isn’t so much that the disease is shifting, although that happens regularly with viruses.

That’s why we have flu shots every year to target whatever strain is expected to be the problem. On Monday, the Centers for Disease Control and Prevention acknowledged that covid is airborne, a position it took in September before walking it back. Diseases aren’t the only things that mutate.

It is important for everyone to acknowledge the realities of what is happening and what we have to do to respond — and also being humble about how much we still don’t definitively know about the virus and how it spreads. In a month, these numbers could shift again, for the worse, or the better.

— The Tribune-Review (TNS)