It spreads so fast because R0 is much higher than before. From ~2.7 to ~4-9. That difference is HUGE, and can make COVID more transmissible than smallpox.
Yet it's killing less because vaccines are protecting the elderly. The young are those getting infected.
But the young don't die as much.
Vaccines are really good, even against Delta. mRNA ones reduce hospitalization and death by ~93%.
So get vaccinated.
But they only protect ~65% against symptomatic infection.
With an R of, say, 8, the herd immunity threshold would go up to ~85%. With a vaccine that only protects 65% of ppl against infection, *even vaccinating all the population would not stop the virus*
That doesn't account for Long COVID, which affects ~1/8 symptomatics. So what can we do?
1. If you're an individual, if you're vaccinated, you're good. Be cautious though. Your likelihood of death is~0.14%, assuming you will get exposed.
If you're not vaccinated, get vaccinated asap. 2 shots ideally. Mix-and-match if you can.
2. If you're a community leader:
Vaccinate, vaccinate, vaccinate. The lives of your community depend on it. Any vaccine that works is better than none. If people are opting out, try to lure them in.
Also, keep Delta at bay as much as you can while vaccinations proceed. An elimination strategy will be best. Good border fences and test-trace-isolate programs are your best tools. Super-spreader events should still be avoided. Masks indoors and in crowds. Great ventilation.
3. If you're in charge of vaccine policy, vaccinate everybody you can. Approve mix-and-match.
COVID prevalence in Europe
Left: July to November 2020
Right: July 2021 so far
To all the countries that have eliminated it in Europe: Don't let your guard down. Keep a fence on your borders. Race to vaccinate. Keep improving test-trace-isolate programs. The speed & gravity of the Delta wave will depend on it.
Should everybody learn to speak English? Yes: 1. Network effects of a common language are stronger than ever in History 2. It's the 1st time these are global 3. English is the most spoken / written language & the fastest growing
Only one thing can prevent this
Thread 🧵
1k years ago, ppl mostly spoke with those around them. Little need for a lingua franca. In Europe, Latin was enough, learned by the Church and the elites.
After the printing press, suddenly you can learn & communicate w/ ppl far away. Incentive to understand each other ➡️ languages appear around the dialects most published. In Europe you go from a gradient of languages to German, English, French, Spanish...
S curves are everywhere. Learning to identify them is a superpower
They're how epidemics evolve
How memes spread
How investment unfold
How businesses grow
How muscles contract
How technology us adopted
How animation flows
How popcorn explodes
How ice melts
How water evaporates
How countries are formed
How magnets snap
How atoms spin
How transistors change their charge
How ppl get promoted
How they succeed
How they're fired
How they're born
How they die
We don't always recognize them because, depending on where we are on an S curve, it might not look like one.
It might look line a horizontal line
Or a vertical one
Or an oblique one
Or an exponential
Or a noisy surve