
Covid-19 is becoming less deadly in Europe but we don't know why - bookofjoe
https://www.newscientist.com/article/2252699-covid-19-is-becoming-less-deadly-in-europe-but-we-dont-know-why/
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orobinson
As the article mentions, it seems more likely that the decreasing death rate
is due to higher rates of young people being infected vs older people. Also
due to increased testing catching the less severe cases.

Back in April here in the U.K even healthcare workers weren’t getting tested.
Now you can get a test posted to your house for free if you show even the
mildest symptoms, so much more of these mild cases are getting counted.

Also, anecdotally, older people are still taking precautions to minimise
contact with others whereas younger people are basically going about life as
normal. Hence, the virus is spreading around younger people much more than
older people. For example, the U.K had a huge number of deaths in care homes
earlier in the pandemic but I believe most care homes are still locked down to
some extent while at the same time the pubs are open and kids are heading back
to school next week.

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iforgotpassword
From what I can tell looking at friends and family, a lot of people are
currently returning from vacation, and it's been on the news a couple times
that those people are bringing back covid, presumably visiting bars and clubs
depending on where they traveled, easing the spread.

That would explain why it's becoming less deadly. The old and vulnerable don't
travel, so we have a disproportionate amount of young people getting infected
which recover well. Let's see how many of those who return can't resist
visiting their grandparents in the first two weeks after returning. Maybe we
get a delayed deadly wave when it hits the retirement homes again.

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gregoriol
It's hard to compare to march: there were no testing numbers at that time,
it's impossible to know how many cases there were back then when hospitals
started to get full of very sick people. We'll probably know in a few weeks.

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bookofjoe
>Evaluating the effects of SARS-CoV-2 Spike mutation D614G on transmissibility
and pathogenicity
[https://www.medrxiv.org/content/10.1101/2020.07.31.20166082v...](https://www.medrxiv.org/content/10.1101/2020.07.31.20166082v1)

>Estimating the infection fatality ratio in England
[https://www.cebm.net/covid-19/estimating-the-infection-
fatal...](https://www.cebm.net/covid-19/estimating-the-infection-fatality-
ratio-in-england/)

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perl4ever
It seems obvious to me that the more people isolate, the more there is
evolutionary pressure on the virus to become more infectious and less
virulent. Even if people didn't "social distance" there would be some
pressure, but the better they do it, the more there is.

I think I remember people saying similar things months ago, and being called
ignorant idiots by angry people on HN, but I was never sure exactly why.

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ivars
I've heard that vitamin D play a big part in successful recovery. Northern
Hemisphere gets their vitamin D mostly in summer so this is the time when
European immunity is the strongest?

~~~
soganess
As far as I can gather this claim stems from a single non-peer reviewed
preliminary report from back in may:

[https://www.webmd.com/lung/news/20200518/more-vitamin-d-
lowe...](https://www.webmd.com/lung/news/20200518/more-vitamin-d-lower-risk-
of-severe-covid-19)

[https://www.yalemedicine.org/stories/vitamin-d-
covid-19/](https://www.yalemedicine.org/stories/vitamin-d-covid-19/)

~~~
ivars
There are many. For example:

[https://link.springer.com/article/10.1007/s40618-020-01370-x](https://link.springer.com/article/10.1007/s40618-020-01370-x)

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badhabit
probably because the most vulnerables are already phased out leaving the more
resistant types

