The Volokh Conspiracy

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Volokh Conspiracy

Is Covid-19 Seasonal?

A National Academy of Sciences report suggests not, but that report gets some basic facts wrong


One of the great unknowns regarding Covid-19 is whether, like many other viruses, it will have strong seasonality and its spread will slow dramatically in the Summer. A recent National Academy of Sciences report suggests that this outcome is unlikely.

I noticed something odd in the study, however. On page six, the report states the countries currently in "summer" climate, such as Australia and Iran, are experiencing "rapid virus spread," and suggests this argues against the theory that heat and humidity will act strongly against the virus.

I happened to have recently perused the Australian Department of Health's website, and according to that site, most of Australia's cases originate from people who traveled abroad and that "currently, Australia does not have widespread community transmission of COVID-19."

I'm also not sure where the authors got the idea that Iran is experiencing summer climate. Qom, the city where the Iranian outbreak has been most intense, has not been above 75 degrees this calendar year, and has generally been much cooler. Tehran has been even chillier.

So I'm not in a position to predict how the weather will affect Covid-19 transmission [and I don't know whether Australia and Iran were just sloppy examples, or if the authors actually relied on them to any degreee], but I am quite disappointed that I apparently can't rely on experts consulted by the prestigious National Academy of Sciences to get basic facts right.