Epidemic one, the first recent pandemic.
The coronary virus pandemic incites all of humanity to the virus. The damage to health, wealth and well-being has already been enormous. This is like a World War, except in this case, we're all on the same side. Everyone can work with to learn more about the disease and develop tools to combat it. I see global innovation as a key to reducing damage. Including innovations in testing and treatments, vaccines, and policies to reduce the spread of the disease while minimizing damage to the economies and well-being.
This note shares my view of the situation and how we can accelerate these innovations. (Because this publication is long, it is also available as a PDF file.) Change position every day, there are a lot of information available - much of it contradictory - it may be difficult to understand all the proposals and ideas that may hear about it. Can also seems that we have all the scientific developments necessary to re-open the economy, but in fact we don't have. Although some of the following gets technical to an extent, I hope that helps people understand what is happening, and to understand the innovations that we still need, and make informed decisions on dealing with the epidemic.
Exponential growth and decline:
In the first phase of the epidemic, we have witnessed the widespread and enormous in a number of countries, starting with China and then throughout Asia, Europe and the United States. The number of casualties was doubling several times a month. If people hadn't changed, most of the population would have been infected. Through behaviour change, has become many countries the incidence of the plateau and start to decline.
Exponential growth is not intuitive. If I say that 2 per cent of the population is infected and this will double every eight days, you will not discover most of the people on the spot that within 40 days, will be the majority of the population. Major interest from the change of power is to reduce the incidence rate significantly so that, instead of doubling every eight days, dropping every eight days.
We use something called the repetition rate, or R0 (pronounced "none"), to calculate the number of new infections caused by an infection earlier. Difficult to measure R0, but we know that it is less than 1.0 wherever decreased the number of cases and higher than 1.0 wherever the number of cases. What may seem to be a small difference in R0 could lead to very significant changes.
If each injury moves from causing 2.0 to causing only 0.7, then 40 days later it will be one sixth of the injury rather than 32 times the injury. That's 192 fewer cases. Here's another way to think about it: if you started with 100 cases in total, after the 40 days, over 17 injured in R0 the minimum and 3200 at the top level. Experts are now discussing how long R0 should remain too low to reduce the number of cases before opening.
The exponential decline is less obvious. A lot of people will be amazed that in many places we will move from hospitals suffering from overload in April to getting lots of empty beds in July. The impact will be confusing, but inevitable from the rapid nature of the infection.
As summer approaches, some sites that maintain behavioural change will see a significant decline. However, as behaviour normalizes, some sites will stumble along with ongoing infection groups, some of which will return to exponential growth. The photo will be more complicated than it is today, with a lot of heterogeneity.
Did I overreact?
It makes sense for people to ask whether a change of behavior is necessary. The answer is yes. There may be a few areas where it wasn't the number of cases gets large numbers of injuries and deaths, but there was no way to know in advance which areas will be. This change has allowed us to avoid many millions of deaths and overburdened hospitals, which would also have increased deaths from other causes.
The economic cost paid to reduce the rate of infection is unprecedented. The drop in employment is faster than anything we've ever seen. The entire economy is closed. It is important to realize that this is not just the result of government policies that restrict activities. When people hear that infectious diseases are widespread, they change their behavior. There was no choice at all for a strong economy for 2019 in 2020.
Most people choose not to go to work or restaurants, or trips, to avoid infection or injury to the elderly in their homes. Confirmed government requirements that a sufficient number of people changed their behavior to get reproduction rate is less than 1.0, which is necessary to get a chance to resume some activities.
