This is a festival: an epidemiological Woodstock with no expiration date. COVID—like SARS and MERS and the various flus before it— is only the beginning. And if history is any judge, future acts will come increasingly thick and fast.
Here’s the thing, though: COVID-19 isn’t nearly as bad as what I’d been expecting.
I’m talking about the actual virus here, not the social impact. The Cassandra prognosis—admittedly a purely theoretical, what-if scenario—imagined a bug with a 10-20% mortality rate, ultimately infecting around half the world’s human population. COVID-19 isn’t anywhere near that lethal. Even the 3.5% kill rate you’ve seen bandied about must be way too high, because it ignores both active cases still pending (42% of the total at this writing, according to the Johns Hopkins Amazing Coronavirus Dashboard) and—more significantly—the proportion of infections that haven’t been detected because they’re asymptomatic. Asymptomatic cases could account for two thirds of the total according to Mizomuto and Chowell, based on the Diamond Princess outbreak (which provides an unusually comprehensive data set, since the entire population was tested for the virus whether they showed symptoms or not).
Yes, the prevalence of asymptomatic carriers increases the infection rate—but that’s a higher infection rate for a much more benign strain of the disease. (There are, so far, at least two strains of COVID-19, the younger and more virulent “L-Type” being responsible for most of the symptomatic cases. But L is already waning—probably because of active control measures— leaving the more benign “S-Type” to outcompete it in the wild). Once the dust clears and asymptomatic cases are fully accounted for, I’d be surprised if this bug racks up a mortality rate much higher than 1%—which, by comforting coincidence, is in the same ballpark as the 0.6% South Korea reported after daily testing thousands of their own citizens, symptomatic or not.
