1/n Over the next few weeks, you'll hear lots on how "top scientists", or "the world's leading scientists", call for a so-called #HerdImmunity approach.
They're a few cranks & shills. It's a lie to say they are "top scientists", or "the world's leading scientists".
cc. @TripeUK https://twitter.com/SkyNews/status/1313776525414666240

2/n The presidents of the four scientific/medical research associations in Germany (Fraunhofer, Max Planck, Helmholtz & Leibniz), have put out a joint position statement on #COVID19, why #HerdImmunity doesn't work, & what measures are needed now.

https://www.mpg.de/15426458/stellungnahme-forschungsorganisationen-covid-24-09-2020.pdf

3/ You can read an auto-translate (i.e. sometimes buggy) of that position statement in English here:

https://translate.google.com/translate?sl=auto&tl=en&u=https%3A%2F%2Fwww.mpg.de%2F15426458%2Fstellungnahme-forschungsorganisationen-covid-24-09-2020.pdf

4/n Points from the German statement:
a/ Trying to only protect the vulnerable, while allowing the #SARSCoV2 ( #COVID19) virus to simply run rampant through the rest of the population, simply doesn't work in practice.

b/ Hygiene/quarantine measures WORK.

In Germany, the first lockdown ended at the end of April with around 2,000 new infections per day, which was reduced down to @ 300 new infections daily.
#TestandTrace, #FaceMasks, #SocialDistancing, and no large gatherings, meant success.

c/ #TestAndTrace simply doesn't work *unless* you also have all the hygiene/quarantine measures in place to suppress the virus. Your testing and tracing systems simply get overwhelmed by the virus running wild [my addition: as too eventually your ER's and ICU's].

d/ Testing capacity [as always] is a limited resource. It needs building up and care [and not getting overwhelmed].
Traced contacts need to be [self-]isolated **in time**, i.e. quickly.
Preventive quarantine WORKS.
Oh, and avoiding super-spreading events really helps too.

you can also read @devisridhar's thread on the same thing. Via, thanks, @LucySetonW https://twitter.com/devisridhar/status/1313733782235680768

a/ A last important point from the German statement. In my own words: over & over again, you hear people claim that #COVID19 has become less lethal. This is absolute bull. Lethality remains widely unchanged from April. What *does* change is median age of the infected.
cc. @TripeUK

b/ If you are unclear about why median age of the infected changes how many people actually die from #COVID19, then see this table (from a different preprint).
If it's younger people on average getting infected, then many fewer die. But they go on to infect others.
cc. @TripeUK