
Covid-19 now exists in two forms, indicating it's already mutated at least once - bookofjoe
https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaa036/5775463?searchresult=1
======
nostrademons
There's some pretty sharp criticism of this paper on the r/COVID19 subreddit
(which is the one where the scientists hang out):

[https://www.reddit.com/r/COVID19/comments/fdsltf/about_the_l...](https://www.reddit.com/r/COVID19/comments/fdsltf/about_the_l_and_s_strains/)

Basically, there are 111 different mutations, not 2, and it's misleading to
point to a single point mutation and set that as the arbitrary division point
between strains while ignoring the other 110 mutations that have been
catalogued. There is currently not enough evidence for the researcher's claims
that this particular mutation causes observable differences in the virus's
reproduction or virulence characteristics that the other mutations do not.

~~~
_bxg1
What about whether or not you can "catch it again" once your immune system has
beaten one version?

~~~
abiogenesis
Immune system is amazing. It can actually detect different strains of the same
virus, even if it has never seen that specific mutation.
[https://www.sciencedaily.com/releases/2018/04/180430212353.h...](https://www.sciencedaily.com/releases/2018/04/180430212353.htm)

> "After exposure to one strain of virus, these memory cells are then better
> able to recognise variants of the virus if they encounter them in the
> future. The immune system learns to protect against a whole group of related
> viruses, not just the one it experienced."

~~~
tryptophan
This is kind of a double edged sword though.

Say the virus mutates so that only 50% of its features are recognizable.

You'd think that the fact that your cells can recognize this is good, and it
is to some extent, but, it also prevents new cells from learning about the
virus(in efforts to prevent autoimmunity in analogous scenarios with non
malicious objects; our immune system has to walk the fine line between being
too permissive and allowing infections, and being too restrictive and
murdering its own host through nasty autoimmune diseases).

So, it mounts a 50% response, which is often good enough, and more than makes
up for the more limited response with speed.

But what happens when the % recognizable drops to like 3%? Some percentage of
cells will recognize the 3%, and be able to mount a weak response, but more
critically, block other cells from developing new responses. This limited
response will slow down a proper response and itself will be likely
ineffective.

Its known as "original antigenic sin", if you want to read more.

~~~
kohtatsu
I hope COVID-19 isn't reading this.

~~~
Eldandan
I'm pretty sure covid-19 doesn't read Hacker News.

------
lacker
The key part of the summary to me is this:

 _Although the L type (∼70%) is more prevalent than the S type (∼30%), the S
type was found to be the ancestral version. Whereas the L type was more
prevalent in the early stages of the outbreak in Wuhan, the frequency of the L
type decreased after early January 2020. Human intervention may have placed
more severe selective pressure on the L type, which might be more aggressive
and spread more quickly. On the other hand, the S type, which is
evolutionarily older and less aggressive, might have increased in relative
frequency due to relatively weaker selective pressure._

It's too early to really know for sure, but one thing that often happens with
viruses is that over time, the less fatal versions spread more effectively. It
might be that the L type is the more lethal type which killed so many people
in Wuhan, and the S type is the more silent type that is spreading around the
world with a lower mortality rate.

Probably just wishful thinking on my part, but it's interesting to be aware of
the possibility.

~~~
flukus
> It might be that the L type is the more lethal type which killed so many
> people in Wuhan, and the S type is the more silent type that is spreading
> around the world with a lower mortality rate.

I suspect this is the main reason we're seeing divergences in different
countries, with South Korea getting the "good" type and Italy getting the bad
one.

> but one thing that often happens with viruses is that over time, the less
> fatal versions spread more effectively

The key here is selection pressure more than time, with no controls in place
there's no selection pressure until it runs out of hosts, until then it's
highly successful and does not need to adapt. In this case we've added some
artificial selection pressure.

If there are places with only the bad type of the virus I wonder if we could
ethically introduce the good type? On one hand your saving overall lives but
you'd be purposefully infecting people with something that potentially has
life long effects.

~~~
remote_phone
I think it has to do with the number of hospital beds per capita. South Korea
has over 12 per 1000 but Italy only has 3.1. That is probably making a huge
difference.

The US only has 2.8 per thousand which is horrifying, I hope the Italy
situation doesn’t happen here.

~~~
dmurray
Wow, how are those numbers so different? You would think a functioning health
care system in any developed country would be similar. The controversial topic
in the US isn't really the quality or quantity of healthcare, it's about who
pays for it.

You might tell me it's because of something unique and bad in the US system,
and we should see the Scandinavian countries to see how it should be done -
but no, Denmark 2.6, Canada 2.5, Sweden 2.2 all have fewer beds per capita
than the US. It's Japan and Korea who are the outliers at the top at 12 and
13. [0]

It really must be a cultural/lifestyle thing. Would I really spend 4 times as
much of my life in a hospital bed if I lived in Korea? And if so, would that
really be a good thing? I assume usage is reasonably high in both, the beds
don't sit empty waiting for a pandemic.

Or you might remind me that those countries have famously old populations. But
that's not it either. Japan has an old population, but still only twice as
many 70+ as the USA (according to the population pyramids at [1]). And Korea
has the same proportion as the US.

It makes me wonder if they are comparing like with like: maybe some of the
reported hospital beds in Korea would be considered to be in nursing homes or
convalescence centres in Europe or the US.

[0]
[https://en.wikipedia.org/wiki/List_of_OECD_countries_by_hosp...](https://en.wikipedia.org/wiki/List_of_OECD_countries_by_hospital_beds)

[1] [https://www.populationpyramid.net/republic-of-
korea/2020/](https://www.populationpyramid.net/republic-of-korea/2020/)

~~~
mysterypie
It is indeed very strange that Korea and Japan should have 400% more hospital
beds per capita than the U.S., Canada, or Scandanavia. I tried to dig into the
OECD methodology[0] to see if they mentioned anything noteworthy, but nothing
grabbed my attention. Their notes about the U.S.[1] and Korea[2] seem pretty
similar. I'm wondering if in Japan and Korea, people stay in hospitals for
longer periods for the same condition than in the U.S. For example, in the
U.S. mothers giving birth would stay in the hospital for a week or more in
1950s from what I heard, but these days they are discharged after a couple
days. What's a typical stay for uncomplicated childbirth in Japan and Korea?
If it's a week or 10 days, then that would give a possible datapoint for
having many more beds.

[0]
[https://stats.oecd.org/index.aspx?DataSetCode=HEALTH_REAC](https://stats.oecd.org/index.aspx?DataSetCode=HEALTH_REAC)

[1] Notes about the United States: Coverage: AHA-registered hospitals in the
United States. U.S. hospitals located outside the United States are excluded.
Includes all the AHA registered hospital beds for all types of hospitals.
Estimates are for all AHA registered hospitals. AHA-registered hospitals
include facilities such as short-term general, psychiatric hospitals, wards,
rehabilitation institutes, maternity homes, tuberculosis hospitals,
leprosariums and alcoholic treatment institutions. Estimates exclude U.S.
associated areas such as Puerto Rico and AHA non-registered hospitals.

[1] Notes about the Korea: Coverage: Hospitals: all sorts of medical
institutions equipped with wards of at least 30 beds. Excludes day-care beds,
emergency beds, surgical tables, recovery trolleys, delivery beds and cots for
normal neonates.

~~~
dmurray
The methodology sounds quite similar, indeed.

Maybe the stays are just longer. In Ireland we've seen the same trend in
maternity hospitals: mother and baby used to stay for a week, now a couple of
days. But I thought that was just best practice now and keeping them longer
doesn't improve health outcomes.

------
glofish
Covid-19 is the name of the disease. The virus is called SARS-Cov-2.

The virus has mutated plenty of times already and exists in many forms not
just two. The paper talks about being able to group existing mutations into
two types. Within each type the genomes share more common elements than
differences.

~~~
microcolonel
The disease differs too though, the mutations are not inert, and they have a
measurable effect on the severity of the complications.

~~~
glofish
the disease does differ greatly already within a subtype, the same subtype may
cause severe or mild effects - the response is primarily host-related, not
virus related

------
jml7c5
See also:
[https://nextstrain.org/ncov/gisaid](https://nextstrain.org/ncov/gisaid)

------
nod
Go look at [https://nextstrain.org/ncov](https://nextstrain.org/ncov) if you
want to see all of the mutation paths! Wonderful site/org with contributors
doing great work around the globe sending in sequences.

------
voldacar
A critique of this paper by some scottish virologists:
[http://virological.org/t/response-to-on-the-origin-and-
conti...](http://virological.org/t/response-to-on-the-origin-and-continuing-
evolution-of-sars-cov-2/418)

------
SubuSS
[https://bedford.io/blog/ncov-cryptic-
transmission/](https://bedford.io/blog/ncov-cryptic-transmission/) \- For
anyone looking for more info around how the transmission/mutation works. Quick
read.

------
jnbiche
Can we please correct the title? This is in reference to the virus SARS-Cov-2.
Covid-19 is the name of the disease.

~~~
birdyrooster
To back your claim: "The disease caused by infection with SARS-CoV-2 is now
called COVID-19."

Source:[https://www.worldaware.com/resources/intelligence-
alerts/sar...](https://www.worldaware.com/resources/intelligence-alerts/sars-
cov-2-and-covid-19-coronavirus-intelligence-center)

------
iskander
Detailed rebuttal:
[https://docs.google.com/document/d/1niBInt7tgQ57iihgenPFMyn7...](https://docs.google.com/document/d/1niBInt7tgQ57iihgenPFMyn7O1NHLLxsrgEQQnxXLSA/edit)

tl;dr this paper should be retracted

------
sizzle
Why does it take so long to develop a deactivated vaccine version of the virus
to teach our immune system what to attack?

------
Munky-Necan
What was interesting about this, that is contrary to common understanding of
virology and pandemics, is that there as a mutation that significantly
increased the virulence of one strain of SARS-CoV-2. Over time, viruses will
become less virulent as they continue to infect new hosts.

~~~
fspeech
They used the word "aggressiveness", which does not necessarily associate with
"virulence". As they are only looking at frequency data at the genomic level
it is everyone's guess on how the distribution is achieved. I take it to mean
shorter incubation time so that it spreads faster but also more easily
impacted through infection control measures.

~~~
Munky-Necan
> It is also unclear whether the L type is more virulent than the S type

You're right. I finally got a chance to read the study fully, but was basing
my comments from the r/COVID-19 thread.

------
ggm
Genes do what genes do. Nothing here is unexpected, surely? But, if the
lethality drops and becomes sustaining in the population, we're still net-
worse-off overall compared to not having had this virus. Its just 'choose the
least-worst outcome' time.

I think at this point, public health initiatives are aimed at moving the shape
of the curve, not the final trajectory of the virus. It's going to spread
everywhere but if it does so more slowly the health system will not be
overloaded by point-explosions of calls on staff and equipment.

I feel for the Tasmanian toilet-paper workers who will work overtime to meet a
panic-demand, and then be unemployed with a mountain of un-wanted rolls, as we
consume the 6 month supply we bought in a frenzy.

------
ngcc_hk
One of the problem is naming. What is the difference of all these names? The L
and the S type are they the one found in patient. Why stress non-recomb...

And all those mainland chinese academics ... sorry but CSB we trust them.

~~~
lacker
Ah, those untrustworthy Chinese academics who are calling for the
controversial action of... more comprehensive followup studies.

~~~
perl4ever
That is controversial in some circles:

"Academic journal editors were banning unqualified FRIN statements as early as
1990"

[https://en.wikipedia.org/wiki/Further_research_is_needed](https://en.wikipedia.org/wiki/Further_research_is_needed)

~~~
stordoff
Remainder of sentence:

", requiring more specific information such as what types of research were
needed, and what questions they ought to address."

Article:

> Further studies investigating how the different alleles of SARS-CoV-2
> viruses compete with each other will be of significant value.

> If these changes are not due to sequencing errors, it would be interesting
> to test whether and how these mutations affect the transmission and
> pathogenesis of SARS-CoV-2.

> Thus, it will be interesting to investigate the function of the S84L AA
> change in ORF8, as well as the combinatory effect of these two mutations in
> SARS-CoV-2 pathogenesis.

> follow-up analyses of a larger set of data are needed to have a better
> understanding of the evolution and epidemiology of SARS-CoV-2. There is a
> strong need for further immediate, comprehensive studies that combine
> genomic data, epidemiological data, and chart records of the clinical
> symptoms of patients with SARS-CoV-2.

I'm not sure if I would call those unqualified statements. Some are a bit
vague, but they do identify questions that should be addressed and that a
larger dataset is required.

~~~
perl4ever
I was being mildly facetious.

