Wednesday, May 13, 2020

Prospects for a vaccine as COVID-19 deaths head for 6 digits by June

Here is sobering, scary modeling covered by NPR: How To Make Sense of All The COVID–19 Projections? A New Model Combines Them. The projections converge on 110,000 deaths by the first week in June.

Enter Nicholas Reich, a biostatistician at University of Massachusetts Amherst. Reich and his colleagues have developed a method to compare and ultimately to merge the diverse models of the disease’s progression into one “ensemble” projection. The resulting forecast is sobering. By June 6, it projects, the cumulative death toll in the U.S. will reach 110,000.

The team unveiled the first version four weeks ago and ever since has been adding in more forecasts and updating the projections weekly. The latest update — released Tuesday — incorporates eight models, including some oft-cited ones, such as those built by the Imperial College London, the University of Washington Institute for Health Metrics and Evaluation, Columbia University and Northeastern University. (The team also sends each week’s release to the CDC, which publishes a version with a slight time lag.)

The projections vary substantially — with the most pessimistic forecasting a total death toll of 120,000 by June 6 and the most optimistic forecasting 103,000 deaths by that date. But the models have been inching closer to each other. Over the past several weeks, the distance between the highest and lowest estimates has halved from a gap of 36,000 deaths two weeks ago to a gap of 17,000 deaths in the most recent update released Tuesday.

Its worth taking a look at the NPR report to get a graphic look at the individual and ensemble projections. The individual models tend to change overtime.

So how do we make sense of these COVID–19 projections if the models can see-saw so abruptly from week to week? That’s where Reich’s “ensemble” model may be helpful. It’s a strategy that forecasters use regularly to model not just disease outbreaks, but other phenomena ranging from weather to electoral outcomes.

Reich thinks he can still improve his ensemble model. For instance, at the moment Reich is giving equal weight to each of the forecasts that go into it. But soon he hopes to give more weight to those that are proving more accurate — an approach that he uses in his ensemble models for flu.

The bottom line is (1) we are far from over this thing, and (2) we can expect yet more fatalities if/when counties, states and the nation reopen.

If we want to reopen, the safest way is to have a vaccine in place. And that is easy to say but hard to do. For a realistic assessment of the hurdles and potential for success, see this NPR report: When Can We Expect A Coronavirus Vaccine?

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