1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Hi Guest, welcome to the TES Community!

    Connect with like-minded education professionals and have your say on the issues that matter to you.

    Don't forget to look at the how to guide.

    Dismiss Notice

Why Covid-19 is more AND less deadly than we knew I VOX

Discussion in 'Science' started by AndrewvanZyl, Jun 5, 2020.

  1. AndrewvanZyl

    AndrewvanZyl Occasional commenter



    With polarized debates raging about whether the novel coronavirus pandemic is serious enough to shut down economies around the world, death counts in the US, and especially in New York, continue to rise, and nobody knows how high they will go. What makes it difficult for us to wrap our heads around this particular disease is that it is unpredictable. That's because it's contagious, the vast majority of people remain susceptible to it, large percentages of infected people never know they are contagious, and we're still far from a vaccine. In this video we explain some of the mortality statistics that researchers are using to characterize this disease. New data show that the coronavirus death count is higher than we thought but the death rate is lower.
     
  2. ChrisH77

    ChrisH77 New commenter

    Closing line... “... we won’t know the full death toll of the pandemic until we know how it ends”. How about we do know how it ends (... has ended) in many countries and regions - at the tail of a Logistic Growth curve.

    In the UK, policy has followed ‘the science’ that places absolute faith in its SIR model of epidemics, and its Case Fatality Ratio being almost 1% (from China and cruise-ship studies). From this, they believe that, because of a Ro of 2.5, and population fatality less than 1/10 of the potential worst case, the country is way short of its 60% ‘herd immunity’, and we remain at risk of a second wave.

    However the SIR model assumes an ideal virus: a uniformly susceptible population, with equal risk of becoming ‘a case’. When we have a virus tearing up every Rule Book thrown at it, one might wonder whether the SIR model is really tenable?

    Has no one else noticed that the excess deaths, shown halfway through the clip, look very like generic Logistic Growth curves? This is the characteristic population growth of natural systems: rabbits, mobile phone subscriptions, infectious diseases... etc: in which growth is exponential at first, then levels off on approach to a ‘carrying capacity’. In any European country where Covid-19 got away from the authorities - Belgium, UK, France, Spain, Italy, etc., the Population Fatality Ratios have passed their peaks of growth-rate, and are converging on the end point of 60 fatalities per 100,000.

    That is a tragedy. But perhaps we can say how it ends (...has ended, almost)?

    What of ‘herd immunity’ and the ‘second wave’? I’d say they are mirages: artefacts of an inappropriate model.
     
    Last edited: Jun 5, 2020

Share This Page