Second Wave? An Opinion

The wavelike character of virus transmission makes it seem as if transmission is understood by just three critical parameters. But virus transmission is not a physical wave.

Virus transmission is affected by measurement error, that is, what’s counted as a confirmation and what’s not counted, and also when it’s counted are subject to error.

The counting depends on testing. The tests have measurement error. But more important is that testing is a nonstationary process. The dependence of reported cases or confirmed cases depends on testing. What may seem to be more virus cases spreading may be more tests spreading.

But also the process generating infections depends on unknown parameters and they and the process may be nonstationary, a moving target so to speak. There actually could be a mixture of processes at work.

One source of nonstationarity is that the virus in question is mutating. One report says that 100 variants have been detected worldwide.

It appears that transmission number (people affected), speed of spread, and seriousness of illness have all varied among continents, varied among countries within continents, varied among individual states within countries, varied among counties within states and varied among places and cities within states. These basic differences are not understood, which means they’re not predictable. They depend on lots of unknown factors like immunity, age, density, sunshine, presence of other diseases, etc., etc.

No one has a multivariate model to explain these differing transmission rates and properties. They come about through trillions of social contacts among 6 billion people, and the number of operative variables is large. No one understands it or can understand it at this time. No one can tell you why Texas or Houston might now be reaching its peak, or why Houston might be peaking but Harlingen is not. There are too many unknown variables. No one can tell you why there are declines in some states, flatness in others and rises in others.

Against this background, talk of a second wave is meaningless. It’s idle speculation. It’s being used for political purposes, but it has no scientific basis.

Without knowledge of the important underlying variables that affect transmission, seriousness, hospitalization and death, the authorities more or less arbitrarily chose some remedies. But they didn’t have any really good theories or models to guide them, and they still don’t. They are still guessing.

They chose masks, hand-washing, distancing, lockdowns, quarantines, contact tracing, etc. Most of these are ad hoc. They knew or should have known early on that it was killing older people with health problems. This was evident in early March and before. The official responses have not been shown to be effective, and they can’t be so shown because the transmission process doesn’t follow a predictable course. Yes, it rises, falls, but that’s hardly a novel property, and the magnitudes of the rise, peak and fall and their durations in time are unpredictable. In addition, the transmission sometimes flatlines.

The disease has costs, and all the ad hoc control methods have costs, especially mass lockdowns. No one, and especially authorities in public health and government, knew what these costs were when they acted to impose measures.

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9:43 pm on June 27, 2020