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Covid-19: Exponential Growth & Epidemics

Covid-19 virus image
A Covid-19, SARS-CoV2 CoronaVirus


Immunologically naive populations

“Viruses have been circulating around the globe for millennia. One family of viruses that have been circulating are referred to as Coronaviruses. About a quarter of common colds are caused by Coronaviruses. Our bodies form antibodies to foreign invaders such as bacteria or viruses. If we have antibodies from a previous exposure then we can rapidly ramp up the production of those antibodies if we are infected by that same virus at a later date. This is why you only get Chicken Pox and the Measles once. The first episode generates protective antibodies so you can’t get infected a second time. For other infections, previous exposures do not make you immune to future infections but it does make subsequent exposures milder.

COVID-19 is a severe respiratory illness caused by the virus named SARS-CoV2. It is a novel virus, which means that no one in the world has antibodies to it because no one has ever been infected by it before. As such, when the COVID-19 virus invades our body we do not have pre-existing antibodies. We do not have a template to utilize from a previous exposure to rapidly create a defense against the virus.

Exponential Spread

Exponential math is very hard to grasp. Every person with the COVID-19 virus infects approximately 2 people. Some less, some more. The doubling time that is widely quoted is 6 days. Some scientists are saying it may be as short as 2–3 days (unpublished first-hand information)! Let’s say the infection rate doubles every 6 days. That means that if 50,000 people have the virus today, then in 6 days 100,000 people will have it. In another 12 days it’s 400,000 and less than two weeks later it’s over a million people. We have 330 million people in the US. The experts expect that 40–70% of people will be infected. Exponential growth does not take that long to get to those scary high numbers. Every 6 days we delay the number of infections double. ” – Howard Luks, MD

Here’s a YouTube Video that does a great job of explaining Exponential Growth. It comes from the Animated Math folks at 3blue1brown

I’m Back!

Open Sesame! Door on the Rooftop Cupola at Hotel Raquel, Havana.
Open Sesame! Door on the Rooftop Cupola at Hotel Raquel, Havana.

For some reason that no one at Word Press or its User Group could explain, I have been unable to access my own blog here since September 2014.

Now, through some weird adjustment I cannot really explain or figure out, I am back in the saddle!

But, having not made any entries in 10 months, I am out of the habit and do not foresee blogging with any regularity. And, who knows, maybe I will be blocked from entering my own blog again after I write this and will finally have to give it up totally!

Anyway…. check out my writings and photography pages – that’s where I am spending most all my time.