Here comes COVID’S fourth wave – or not

So are we having a fourth wave of the COVID-19 pandemic in the U.S. or not? University of Minnesota’s Michael Osterholm has forecast a COVID “Category 5 hurricane” this spring. To some people, a look at hard-hit Michigan could justify this level of alarm.

But Paul Offit of the Children’s Hospital of Philadelphia could also claim to be right with his much more optimistic view that vaccines will mostly tame the pandemic from this point forward. After all, U.S. death rates and hospitalizations are not spiking and may never return to anything close to the fall/winter peak.

Predictions have become a Rorschach test where people can find doom or hope or reassurance. But what’s becoming clear is that public health officials don’t really know why this pandemic rises here and falls there.

It’s no longer plausible that it’s all happening because of mask mandates — or tightening or loosening restrictions more broadly. If restrictions and rules were the only factor at play, the current surge wouldn’t be in Michigan but in a state that has reopened more aggressively, such as Texas or Florida. And cases wouldn’t be so high in those previous paragons of virtue, Maine and Vermont. And why would cases be rising now in Canada?

In an interview last month, University of California, San Francisco physician Vinay Prasad brought up a few factors that might influence regional and national waves. One is initial conditions. In the first wave, some states in the Northeast had many more silent cases than others, so cases stayed high in New York and New England despite draconian policies. Another is variants. Michigan might have been unlucky to have been seeded with more people with the more infectious variant of the virus, B.1.1.7.

Regional differences in COVID-19 peaks may also reflect irregularity in the way cases are reported, said Prasad. There are huge differences state to state in how many people are tested, which people are tested, and how positives are tallied up.

Faye Flam is a syndicated columnist.