Today was a big news day on COVID-19, with the news breaking that researchers at Harvard have published a study in Science finding that social distancing would need to remain in force all the way into 2022.
That, at least, was the dismaying headline.
Actually, the news wasn’t quite that bleak. The paper focused on “intermittent” social distancing, which is not the same thing as another two years of the current “shelter in place.” https://science.sciencemag.org/content/early/2020/04/14/science.abb5793?rss=1 What it found was that because of the virus’s tendency to rebound, periodic distancing measures would be necessary to beat back future peaks, in order to avoid overwhelming the hospitals.
Bad enough, but it could be a lot worse.
The researchers also found that viruses of this type appear to be seasonal, which means a likely respite in the summer. In their model, the rebound from that respite tended to produce another big spike in early fall, with the need for a re-institution of social distancing measures. That would be followed by a long series of spikes and respites—possibly as many as three year, lasting into 2022, and possibly as far into the future as 2025 until overall “herd immunity” has risen to a level to eventually damp out the virus.
But it’s a model, and with any model, a vital issue is the assumptions that went into it.
As a science writer, I got to sit in on teleconference announcing this find, and one thing that emerged is that the study didn’t examine different degrees of social distancing, or delve into which of the shotgun blast of control measures we fired at it this time, will actually prove to have been necessary.
By the time the next spike approaches, we should have had time to learn a lot more about exactly how this virus spreads, and hopefully have a much more nuanced approach to dealing with it.
Nor did the model factor in the effect of improved therapies for people who get ill, or the effect of better contact tracing and testing, both of which should become available if public health agencies make good use of the summer respite to gear up for the fall. All that the model shows is how the virus is likely to behave if the only control measures are akin to the ones we are using today.
It also assumes that only a small fraction of the population have, to date, had the virus, recovered, and become immune. And that brings us to today’s second piece of news.
In an announcement https://www.bloomberg.com/news/articles/2020-04-15/china-s-data-on-symptom-free-cases-reveals-most-never-get-sick that got a lot less attention, but which is potentially very good news, the Chinese released their first data on people who were tested for COVID-19 under their contact-tracing and quarantine program, which, whatever else you may think of the Chinese data, was a lot more robust than anything we’re currently doing in the U.S.
What they found was that in a group of 6,764 people who, on contact tracing, tested positive for the virus (and presumably therefore counted as cases in the Chinese data) only 1,297 of them ever developed symptoms. I.e., 81 percent of cases, at least in this data set, were asymptomatic.
What that means for the U.S. is enormous.
For every actual illness, there may be five whose symptoms are so small that nobody noticed…and we are far, far from yet being able to identify every case. It’s quite possible that as many as 90-95 percent of infections have never been identified.
If true, that’s extremely good news.
First, it means that deadly as this disease is, it’s far less deadly than initially believed.
But it might also mean that enough people have already gotten it that we might have enough herd immunity to affect transmission, and we might not see anywhere nearly as many recurring cycles as projected by the Harvard study.
Not to mention that the Harvard study didn’t incorporate the development of a vaccine, since nobody knows when that will happen, or how effective it will be, when/if we get one.
But, the last I heard, several candidate vaccines are already completing safety trials and heading into the next round of testing. We still aren’t likely to see a vaccine until next year, but if if any of them pans out, that’s the game-changer we all want.