Day 94: Still Not the Flu

Cases in Massachusetts are up only 1.5% today, though this may be lag from the weekend. Neither the state nor PlagueBlog is maintaining a 3-day running average of our numbers, but the New York Times has graphed our seven day average among plenty of other colorful stats.

For reasons that remain obscure to PlagueBlog, we are not supposed to compare COVID-19, a viral respiratory infection spread by droplets that tends to kill the elderly in large numbers mainly via the accompanying pneumonia, to the flu, a viral respiratory infection spread by droplets that tends to kill the elderly in large numbers mainly via the accompanying pneumonia. The Wall Street Journal didn't get the memo, and actually compared the two last month. Despite missing the memo, they managed to hit a bunch of the usual specious arguments without ever really answering the title question, Why Doesn’t Flu Tank Economy Like Covid-19?

PlagueBlog has a simple answer: because we're used to the flu. If you gave it a fake name and said it was going to kill 60,000 mostly old folks in the US this season, we might all freak out and shelter in place. But since it's been killing large quantities of people every year since before the Spanish flu, we give it a pass. This is not to say that we should tank the economy for the flu, too, or even that we shouldn't have done it for the coronavirus. PlagueBlog is just answering the WSJ's rhetorical question.

And, of course, PlagueBlog is willing to compare coronavirus to the flu. Some would say you cannot compare the two because we have a vaccine for the flu, but actually, the flu goes on killing the elderly in large numbers despite the vaccine, while, PlagueBlog hopes, COVID-19 will actually be stopped by a vaccine. (It seems one is not allowed to say the flu is worse than coronavirus, but one may say coronavirus is worse than the flu.)

Some would say you cannot compare COVID-19 to the flu because the death counts are vastly different. While it's true that the death counts are different, the difference is less than an order of magnitude. Coronavirus has already slightly exceeded a bad flu year in the US (69,000 vs. e.g., 61,100 in 2017–2018). The US is a heavily vaccinated country, but worldwide the flu is still well in the lead: recent estimates put the worldwide annual flu death toll at 291,000 to 646,000. The current coronavirus death toll is only 250,000, and while it seems likely to equal a mild flu year (especially considering undercounting of deaths), it's less likely to match the flu in a bad year.

Some have suggested that the number of low-grade and asymptomatic cases in the community matters somehow, especially (it seems) because we're having trouble detecting them for COVID-19. However, we have similar difficulties detecting low-grade and asymptomatic flu cases, which is why flu rates and deaths need to be modeled rather than simply counted outright. Due to the current intense interest, prospects are somewhat better for calculating IFR (infection fatality rate) for all conceivable cases of COVID-19, and this number will certainly be lower than the more useful CFR (case fatality rate), which at least tells you something about the chance a particular sick patient will survive the disease. However, PlagueBlog fails to see how this forthcoming low number will somehow lessen the impact of the actual deaths of the 250,000 dead victims of COVID-19.

Similarly, some claim that dying all together from COVID-19 in the first four months of the year is somehow different and worse than dying at a slower rate over the eight months of flu season. The one-time debut speed of COVID-19 does have some potential effect on the health care system and access for other patients. But, since we still don't have particularly good treatments for COVID-19 (that an infected patient might be missing out on due to rationing of health care), the speed of infection seems a minor issue compared to the absolute number of COVID deaths.

Some feel that the occasional deaths of young people from COVID-19 is somehow worse than the occasional deaths of young people from the flu. But the flu actually kills between ten thousand and a hundred thousand children under 5 each year, not to mention plenty of other young people at higher rates than COVID-19. PlagueBlog begs you to think of the children.