OT: COVID-19 thread #2

[dice]

As I said, if you arranged all the questions/answers like I did and let an orangutan pick next to the CDC, the orangutan would have got more right.

WHO now saying that asymptomatic spread of the virus is very rare. If true, that would make the lockdowns one of the dumbest, most destructive public health and economic policy decisions of all time.

But they didn't know that at the time- so the lockdown was still a smart decision. You have to make decisions on your best available knowledge. If they had not locked down, and asymptomatic spread was common, we would have had 3 or 4 times the number of deaths that we did. And then everyone would be blaming them for not shutting down.

Also, the shelter in place made it imperative that people who were sick stay at home. If they hadn't enforced a universal shut down, a lot of sick people would have been out living their normal lives, spreading the virus like wildfire.

asymptomatic spread or not, shutdowns have helped avoid 4.8 million additional DIAGNOSED cases and 60 million infections:

https://www.cnbc.com/2020/06/08/lockdowns-prevented-nearly-5-million-us-coronavirus-cases-study-says.html

that's 250% more than the 1.9 mil plus we have seen to date

and the deaths would have been disproportionately higher given hospital capacities. so yeah, we would have very likely had 3-4 times as many deaths so far

[DuckIII]

A recent study says our social distance has so far prevented over 60,000 new cases.

Edit: that was supposed to be 60 million.

https://www.google.com/amp/s/amp.cnn.com/cnn/2020/06/08/health/coronavirus-shutdowns-effective-study-wellness-bn/index.html

[dice]

A recent study says our social distance has so far prevented over 60,000 new cases.

do you mean deaths?

[Dez]

A recent study says our social distance has so far prevented over 60,000 new cases.

The protests and rioting will fix that in the coming weeks.

[dice]

As I said, if you arranged all the questions/answers like I did and let an orangutan pick next to the CDC, the orangutan would have got more right.

leave trump out of this

[dice]

sound familiar?

https://www.nytimes.com/2020/06/08/world/europe/uk-quarantine-johnson.html

and the polar opposite:

https://www.nytimes.com/2020/05/23/world/asia/jacinda-ardern-coronavirus-new-zealand.html?campaign_id=154&emc=edit_cb_20200608&instance_id=19194&nl=coronavirus-briefing&regi_id=94658923&segment_id=30390&te=1&user_id=7ea4e9d4dbdb5ec9d68d451510e3f47d

and brazil can't handle the dead bodies as their president promotes chloroquine and hydroxycholoroquine:

https://www.nytimes.com/2020/06/08/opinion/brazil-coronavirus-bolsonaro.html?campaign_id=9&emc=edit_nn_20200608&instance_id=19177&nl=the-morning&regi_id=94658923&segment_id=30343&te=1&user_id=7ea4e9d4dbdb5ec9d68d451510e3f47d

epidemiologists expect themselves not to be doing the following for around a year from now or more:

-weddings and funerals
-hugs/handshakes
-go to church
-stop wearing face covering
-attend a sporting event, concert or play
-go out with someone you don't know well

https://www.nytimes.com/interactive/2020/06/08/upshot/when-epidemiologists-will-do-everyday-things-coronavirus.html?campaign_id=154&emc=edit_cb_20200608&instance_id=19194&nl=coronavirus-briefing&regi_id=94658923&segment_id=30390&te=1&user_id=7ea4e9d4dbdb5ec9d68d451510e3f47d

[2018C3]

I'm still convinced Like I said earlier in this topic that the lockdown had the potential to cause more harm than good. As it stands today I believe it has.

I have taken precautions and have been self isolated for months, and am just starting to venture out, I'm still taking precautions with masks and gloves. I have self cooked each and every meal except for one since this all started. I don't think the lifting of this lock down has magically made anyone's life any safer.

The local economy is starting to open up again, we will all know the answers soon.

As it stand now 113,000 people in the US have now died from this virus since it first started. This equals 1 in every 2904 people over a several month span.

The average death toll per month in the US is 234,785 people, or 2,813,420 a year per 2017 statistics. Come January 1, 2021 it will be interesting to see how many additional US people have passed in 2020, and what the real death toll is related to this virus, compared to a average year.

I'm sure it will be higher,but by how much?

[molepharmer]

.....On antibodies, again, from the start they were saying it's likely antibodies will be developed and help protect you, but they didn't have evidence of it. And I'm not sure they still do have that evidence.

There's never been a question of whether antibodies work. They do. Abs have been one of the primary defense mechanisms the human body has used to ward off infection since the beginning of time. Convalescent serum is not a new therapy.

The great unknown is how long will one's neutralizing Abs work and what level of Ab is necessary to maintain some kind of immunity against infection (or re-infection). The only way of answering that is with time. It's why they don't know if once a vaccine has been made, will individuals need booster shots.

Then you have to hope the Covid-19 doesn't mutate to the extent of making the vaccine useless. Fortunately Covid mutates less than most viruses because of it's unique proof reading system and even less so in the spike region which is where many of the vaccines are being directed.

I don't think people realize how fast science is progressing during this pandemic. The first genomic sequence for SARS/MERS was ~2 years after those appeared. For Covid-19 the sequence was known within ~2 months. Groups are publishing pre-print, non-peer reviewed, articles at record pace. There are currently 398 (or 216 ongoing) clinical trials for hydroxychlorquine/chloroquine. Manufacturers are attempting to get out a vaccine by the end of this year, most likely next year. But that's still a record pace. Unfortunately speed doesn't always produce high quality results and magnifies flaws in an ill prepared system (e.g. article retractions, test kits, poor tracing). Our understanding of the Covid-19 pandemic is constantly changing - probably one reason why we see so many models; we're trying to make educated guesses on what the future may hold.

[DuckIII]

A recent study says our social distance has so far prevented over 60,000 new cases.

do you mean deaths?

Cases. But I meant to write 60 million.

[Red8911]

The WHO is pretty much always used as a political football. If they over prepare for a potential epidemic/pandemic, then they get blamed for ruining the economy. If they under prepare, they get blamed the rise in infections/fatalities. Politically, they are always in a lose-lose situation.

They have no power or jurisdiction at all. They can't force themselves into a country to study without the country's approval. They can't force China to tell them what's really going on. The only thing they can do is evaluate the data as they get it. When dealing with something novel, it's nearly impossible to say anything definitive without extensive studies and the replication of those studies from different labs. Unfortunately, science is slow, but a country's response to the information at hand is purely on the government of that country.

South Korea had the same exact info as the US and everyone else from the WHO. They took the antigen test from the WHO in late Jan and told their medical companies to start mass producing testing kits. By early March, they tested something like 150k people when the US still hadn't even declared an emergency! The FDA didn't even allow private companies to start testing until mid March while SK started in late Jan/early Feb. SK didn't have any extra/insider info that nobody else had, they had a playbook they developed from lessons they learned from MERS, SARS, H1N1, etc. It's silly to blame public health experts when in reality it's politics that get's in the way of addressing serious global problems. Pandemics now are a political football in the US which is incredibly scary to think about.

Good post. And the CDC was warning Trump administration officials of the likelihood that this would become a pandemic in mid January, and throughout February, and Trump was just laughing about it, saying that soon our cases would be down to zero. Can't really blame the CDC, which has also been underfunded for years, for that.

Fake news once again from you. Trump laughed about it?
Did he not stop flights to/from China which saved a lot of people from getting sick? What did the democrats do, criticize that move and called him xenophobic.Pelosi was telling people to continue going out to public places and to eat at restaurants.
Thank goodness they weren’t in charge during this time!

When trump said the cases could drop to zero the US only had about 5 cases at the time and he also mentioned that the numbers could go up but hopes they don’t. No one in the world knew it was going to get this bad and this affected everyone, not just trump and the US. You can’t shut down the whole country over 5 cases. When the numbers went up that’s when governors took action to close states down.

Overall Trump did a fine job, there’s not much else he could of done. Then blaming him over the tests is just BS, lets not blame the people who make the tests and send them nah doesn’t fit the narrative, Trumps at fault for everything lol.

[Dresden]

The WHO is pretty much always used as a political football. If they over prepare for a potential epidemic/pandemic, then they get blamed for ruining the economy. If they under prepare, they get blamed the rise in infections/fatalities. Politically, they are always in a lose-lose situation.

They have no power or jurisdiction at all. They can't force themselves into a country to study without the country's approval. They can't force China to tell them what's really going on. The only thing they can do is evaluate the data as they get it. When dealing with something novel, it's nearly impossible to say anything definitive without extensive studies and the replication of those studies from different labs. Unfortunately, science is slow, but a country's response to the information at hand is purely on the government of that country.

South Korea had the same exact info as the US and everyone else from the WHO. They took the antigen test from the WHO in late Jan and told their medical companies to start mass producing testing kits. By early March, they tested something like 150k people when the US still hadn't even declared an emergency! The FDA didn't even allow private companies to start testing until mid March while SK started in late Jan/early Feb. SK didn't have any extra/insider info that nobody else had, they had a playbook they developed from lessons they learned from MERS, SARS, H1N1, etc. It's silly to blame public health experts when in reality it's politics that get's in the way of addressing serious global problems. Pandemics now are a political football in the US which is incredibly scary to think about.

Good post. And the CDC was warning Trump administration officials of the likelihood that this would become a pandemic in mid January, and throughout February, and Trump was just laughing about it, saying that soon our cases would be down to zero. Can't really blame the CDC, which has also been underfunded for years, for that.

Fake news once again from you. Trump laughed about it?
Did he not stop flights to/from China which saved a lot of people from getting sick? What did the democrats do, criticize that move and called him xenophobic.Pelosi was telling people to continue going out to public places and to eat at restaurants.
Thank goodness they weren’t in charge during this time!

When trump said the cases could drop to zero the US only had about 5 cases at the time and he also mentioned that the numbers could go up but hopes they don’t. No one in the world knew it was going to get this bad and this affected everyone, not just trump and the US. You can’t shut down the whole country over 5 cases. When the numbers went up that’s when governors took action to close states down.

Overall Trump did a fine job, there’s not much else he could of done. Then blaming him over the tests is just BS, lets not blame the people who make the tests and send them nah doesn’t fit the narrative, Trumps at fault for everything lol.

Yes, Trump was laughing about the seriousness of it. He made light of it, and the list of things he failed to do is a long one, and has been listed on this forum numerous times, so I won't repeat them. Closing off flights from China did not do much since most of the cases on the east coast were originating from people coming back from Europe.

[Red8911]

Good post. And the CDC was warning Trump administration officials of the likelihood that this would become a pandemic in mid January, and throughout February, and Trump was just laughing about it, saying that soon our cases would be down to zero. Can't really blame the CDC, which has also been underfunded for years, for that.

Fake news once again from you. Trump laughed about it?
Did he not stop flights to/from China which saved a lot of people from getting sick? What did the democrats do, criticize that move and called him xenophobic.Pelosi was telling people to continue going out to public places and to eat at restaurants.
Thank goodness they weren’t in charge during this time!

When trump said the cases could drop to zero the US only had about 5 cases at the time and he also mentioned that the numbers could go up but hopes they don’t. No one in the world knew it was going to get this bad and this affected everyone, not just trump and the US. You can’t shut down the whole country over 5 cases. When the numbers went up that’s when governors took action to close states down.

Overall Trump did a fine job, there’s not much else he could of done. Then blaming him over the tests is just BS, lets not blame the people who make the tests and send them nah doesn’t fit the narrative, Trumps at fault for everything lol.

Yes, Trump was laughing about the seriousness of it. He made light of it, and the list of things he failed to do is a long one, and has been listed on this forum numerous times, so I won't repeat them. Closing off flights from China did not do much since most of the cases on the east coast were originating from people coming back from Europe.

The virus started from China and at the time they had the most cases so it actually did do much . Fauci even admitted that this move saved a lot of lives.

Why can’t you at least give credit to Trump when he clearly did the right thing? Also when Europe was starting to get bad mostly Italy then they shut down all flights to Europe as well.

[Dresden]

Fake news once again from you. Trump laughed about it?
Did he not stop flights to/from China which saved a lot of people from getting sick? What did the democrats do, criticize that move and called him xenophobic.Pelosi was telling people to continue going out to public places and to eat at restaurants.
Thank goodness they weren’t in charge during this time!

When trump said the cases could drop to zero the US only had about 5 cases at the time and he also mentioned that the numbers could go up but hopes they don’t. No one in the world knew it was going to get this bad and this affected everyone, not just trump and the US. You can’t shut down the whole country over 5 cases. When the numbers went up that’s when governors took action to close states down.

Overall Trump did a fine job, there’s not much else he could of done. Then blaming him over the tests is just BS, lets not blame the people who make the tests and send them nah doesn’t fit the narrative, Trumps at fault for everything lol.

Yes, Trump was laughing about the seriousness of it. He made light of it, and the list of things he failed to do is a long one, and has been listed on this forum numerous times, so I won't repeat them. Closing off flights from China did not do much since most of the cases on the east coast were originating from people coming back from Europe.

The virus started from China and at the time they had the most cases so it actually did do much . Fauci even admitted that this move saved a lot of lives.

Why can’t you at least give credit to Trump when he clearly did the right thing? Also when Europe was starting to get bad mostly Italy then they shut down all flights to Europe as well.

Ok, I'll give Trump credit for that. Now will you accept blame for all the things he's botched? Like not getting testing ramped up? Forcing states to compete against themselves for supplies? Not listening to his own CDC when they told him how serious this would be in early February? Continually lying to the American people in his press conferences, like saying anyone who wanted a test could get one? By showing up to factories and not following the protocol of his own CDC and wearing a mask? Like encouraging churches to re-open, when the CDC was saying that wasn't wise? You could go on and on with such a long list of the ways he's botched this. So again, will you admit his mistakes? Or continue to say he did the best anyone could do?

[PlayerUp]

Why can’t you at least give credit to Trump when he clearly did the right thing? Also when Europe was starting to get bad mostly Italy then they shut down all flights to Europe as well.

Viruses like COVID-19 are the start of what is to come. We could see this happen again in the future. The right thing to do is not just ban travel to Europe but all countries. Had that been done when we learned about COVID-19, over 100,000 american lives would have been saved by now, we wouldn't have had to shut down our economy. Yes the virus would have eventually reached the US but banning travel and making it mandatory for people to be checked would have greatly reduced all the problems we're going through now.

[dice]

Fake news once again from you. Trump laughed about it?
Did he not stop flights to/from China which saved a lot of people from getting sick? What did the democrats do, criticize that move and called him xenophobic.Pelosi was telling people to continue going out to public places and to eat at restaurants.
Thank goodness they weren’t in charge during this time!

When trump said the cases could drop to zero the US only had about 5 cases at the time and he also mentioned that the numbers could go up but hopes they don’t. No one in the world knew it was going to get this bad and this affected everyone, not just trump and the US. You can’t shut down the whole country over 5 cases. When the numbers went up that’s when governors took action to close states down.

Overall Trump did a fine job, there’s not much else he could of done. Then blaming him over the tests is just BS, lets not blame the people who make the tests and send them nah doesn’t fit the narrative, Trumps at fault for everything lol.

Yes, Trump was laughing about the seriousness of it. He made light of it, and the list of things he failed to do is a long one, and has been listed on this forum numerous times, so I won't repeat them. Closing off flights from China did not do much since most of the cases on the east coast were originating from people coming back from Europe.

The virus started from China and at the time they had the most cases so it actually did do much . Fauci even admitted that this move saved a lot of lives.

Why can’t you at least give credit to Trump when he clearly did the right thing? Also when Europe was starting to get bad mostly Italy then they shut down all flights to Europe as well.

they never shut down all flights to europe. he incorrectly stated that in his zombie-like televised address to the american people, causing panicked americans in europe to book exorbitantly priced fights back. just one more of countless screwups. the reality is that the suspension of flights did not apply to the UK, nor american citizens, who were free to acquire and bring back COVID-19 from any country they wished. he also said that trade would be halted, which was also not the case

as for china, US citizens were also permitted to do as they pleased. they were just asked to quarantine after their return.
hundreds of planes were still arriving here from beijing on a daily basis. and hundreds of thousands of people came here from china in the month of january

it was the consensus recommendation of US health officials that trump restrict travel to china. but there is no evidence that it had any impact on slowing the spread of the virus. and china had already begun suspending flights, causing airlines to cancel flights due to low traveler volume

early january - trump's daily brief warns of mysterious respiratory illness spreading in china
jan 8 - CDC issues public alert
jan 9 - china releases genetic data on the virus
jan 17 - CDC begins screening passengers in NYC, san fran and LA
jan 18 - trump calls HHS secretary "alarmist" during a discussion about the outbreak
jan 20 - first US case reported
jan 22 - trump: "it's one person coming in from china...it's going to be just fine
jan 23 - china shuts down wuhan, singapore restricts travel to china
jan 24 - trump praises china's response
jan 29 - coronavirus task force created, focusing on US-china travel
jan 29 - trump informed by trade advisor of possibility of as many as half a million deaths
jan 30 - WHO declares international public health emergency, HHS warns trump about possibility of pandemic
jan 31 - HHS declares public health emergency

feb 2 - trump's china travel restrictions take effect
feb 5 - HHS, after having requested funding in late jan due to "startling shortage of medical PPE, formally requests $4 billion. white house is outraged
feb 12 - director of national intelligence scheduled to deliver assessment to house intelligence committee on US unpreparedness for global pandemic. trump administration postpones it w/o explanation
feb 15 - hundreds of US nationals stranded on cruise ship w/ 14 infected individuals are evacuated after trump had expressed concern about them "increasing the numbers"
feb 17 - homeland security begins advocating federal leadership on shutdowns
feb 24 - trump: "coronavirus is very much under control in the USA"
feb 25 - prominent CDC official indicates that "disruption to everyday life might be severe." trump is furious
feb 25 - HHS secretary testifies to senate about dearth of PPE
feb 26 - trump: "15 within a couple of days is going to be down close to zero - that's a pretty good job we've done"
feb 26 - health expert mike pence replaces HHS secretary as leader of coronavirus task force. he becomes the first person to coordinate planning and response, two months after we had learned of the virus

mar 3 - republican ohio governor cancels schwarzenegger sports festival despite no confirmed cases in state
mar 6 - trump authorizes $8 billion to HHS for medical PPE, a month after having balked at half that amount, by which point we are competing for supplies with many other nations. states denied federal assistance, forcing them to bid against each other. trump refuses to order businesses to ramp up production, letting the free market do its thing
mar 9 - ohio and iowa first to declare state of emergency, ohio after reporting first cases
mar 10 - NY, MA and WA transition to online college classes
mar 12 - most major sports leagues suspend seasons, public school closures in many states
mar 12 - HHS places first order for N95 respirators. former HHS secretary: "we basically wasted two months"
mar 15 - CDC recommends against 50+ person gatherings for 8 weeks
mar 15 - illinois and ohio ban dine-in customers at restaurants and bars
mar 15 - puerto rico first to close non-essential businesses
mar 16 - trump issues guidelines urging avoidance of 10+ person gatherings and restriction on discretionary travel until perhaps july or august
mar 17 - trump: "this is a pandemic...i felt it was a pandemic long before it was called a pandemic"
mar 17 - CA issues first stay at home orders
mar 18 - spring break in florida!
mar 21 - trump tweets about hydroxychloroquine
mar 27 - stimulus bill signed into law
late march - US performing 110,000 tests per day. experts say 500,000 are necessary daily

early apr - still several states w/ no restrictions
apr 9 - protest outside OH governor daily press conference
apr 14 - trump halts WHO funding
apr 15 - MI stay at home order protests despite cases rising
apr 16 - trump unveils federal guidelines for 3 phase reopening of economy, w/ each phase lasting at least 2 weeks and strong testing/decrease in cases required
apr 18 - IN stay at home protests despite cases rising
apr 20 - texas begins phased reopening - "there are more important things than living" - lieutenant gov. dan patrick
apr 24 - GA allows gyms, salons and tattoo parlors to reopen - widespread condemnation

may 1 - OH phase 1 reopening
may 19 - OH downgrades stay at home to "strong recommendation"
may 22 - MI phased reopening

june 1 - MI stay at home order lifted

as for democrats calling him xenophobic, there was a fake tweet falsely attributed to chuck schumer. and a misleading video made about a pelosi tweet that was unrelated to the travel ban. and biden noted trump's "record of hysteria and xenophobia" but did not specifically mention the travel restrictions. he DID mention that trump had been advocating travel bans during the 2014 ebola epidemic in which the obama administration listened to the science and chose a different tact:

Read on Twitter

know where a lot of chinese people travel to? japan, singapore and korea. there were no travel restrictions on those countries, nor were we testing those who arrived from those nations

trump has weaponized the pandemic to divide the nation, which is unconscionable. he has consistently undersold the damage that would be done, fixated on the stock market and rooted on protesters against his own administration's recommendations. and he hasn't cared much about the pandemic for some time now. he's currently trying to find a location that will let him accept the birther party nomination for president in front of a packed, sycophantic crowd

and let's not forget that trump dismantled obama's pandemic response team to save money

[dice]

harvard study suggests COVID-19 may have been spreading in wuhan as early as late summer:

https://abcnews.go.com/International/satellite-data-suggests-coronavirus-hit-china-earlier-researchers/story?campaign_id=154&emc=edit_cb_20200609&id=71123270&instance_id=19244&nl=coronavirus-briefing&regi_id=94658923&segment_id=30492&te=1&user_id=7ea4e9d4dbdb5ec9d68d451510e3f47d

[PlayerUp]

trump has weaponized the pandemic to divide the nation, which is unconscionable.

Trump or no Trump the dividing of the nation was inevitable. The worst has yet to come. Swap Biden for Trump in 2020, now you have the right side fighting back and the far left pushing Biden for their extreme left socialist policies. When you have different people wanting different things and neither political party is willing to break away from their party and come back down to earth to focus on core issues like the immense debt crisis we're in for a major recession far worse than 2008 with hyperinflatation imminent.

We need a moderate federal government more than ever and/or more than 2 party system. US is falling apart and our leaders, the media and these extremist mobs are the core issue.

[dice]

trump has weaponized the pandemic to divide the nation, which is unconscionable.

Trump or no Trump the dividing of the nation was inevitable

the nation was already very divided. trump is a symptom of that and has exploited and exacerbated it

Swap Biden for Trump in 2020, now you have the right side fighting back and the far left pushing Biden for their extreme left socialist policies. When you have different people wanting different things and neither political party is willing to break away from their party and come back down to earth to focus on core issues like the immense debt crisis we're in for a major recession far worse than 2008 with hyperinflatation imminent. We need a moderate federal government more than ever and/or more than 2 party system. US is falling apart and our leaders, the media and these extremist mobs are the core issue.

1) the democratic party is very broad. everything from moderates in red districts to far left in very blue districts. biden has always positioned himself in the center of the party and there's no reason to believe that will change. he won the nomination because there's simply not a broad appetite for the kinds of far left policies that bernie sanders and others advocate for

2) we do not have an immense debt crisis. we have a relatively high debt, but more importantly a strong credit rating. because we have the wealth to pay off that debt relatively quickly if necessary. net government debt as % of GDP along with S&P credit rating:

153.04 A+  Japan
119.885 BBB  Italy
108.098 BBB  Portugal
90.324 AA  Belgium
87.651 AA  France
86.344 A  Spain
82.268 AA+  United States
78.166 AA  United Kingdom
66.413 BBB  Hungary
59.829 AA-  Ireland
57.928 AA  Israel
54.32 AA+  Austria
49.159 AA-  Slovenia
46.668 A-  Poland
46.173 AAA  Netherlands
46.12 BBB+  Mexico
45.099 AAA  Germany
41.27 BBB  Colombia
33.344 A  Iceland
29.717 A+  Lithuania
27.793 AAA  Canada
26.918 A+  Latvia
23.053 AAA   Switzerland
22.869 AA-  Czech Republic
22.736 B+  Turkey
22.574 AA+  Finland
19.094 AAA-  Australia
16.273 AAA  Denmark
9.014 AAA  Sweden
6.609 AA  Korea, South
5.257 A+  Chile
4.649 AA  New Zealand
-0.572 AA-  Estonia
-8.284 AAA  Luxembourg
-90.469 AAA  Norway

the countries with BBB+ or worse ratings might be considered to have "debt problems". maybe poland w/ A- rating as well? iceland and spain w/ A ratings? that's about as far as you could reasonably stretch that characterization

3) why would hyperinflation be imminent? and why do you think this recession will be far worse than 2008 when it has not been caused by underlying economic problems?

[Dresden]

WHO clarifies comments on asymptomatic spread of coronavirus


Anne Gulland
,The Telegraph•June 9, 2020

...However, after experts called her comments into question she told a live question and answer session the following day that her comments on asymptomatic spread were based on small number of studies of contact tracing and cluster investigations. She added that modelling estimates suggest that up to 40 per cent of transmission was by asymptomatic carriers.

...Some scientists expressed surprise at Dr Van Kerkhove's initial comments.

Liam Smeeth, professor of clinical epidemiology at the London School of Hygiene and Tropical Medicine, said evidence so far suggests that asymptomatic and pre-symptomatic are an "important source of infection to others".

"There remains scientific uncertainty, but asymptomatic infection could be around 30 per cent to 50 per cent of cases. The best scientific studies to date suggest that up to half of cases became infected from asymptomatic or pre-symptomatic people," he said.

https://news.yahoo.com/true-asymptomatic-spread-coronavirus-rare-103749400.html

[Dresden]

From the Mayo Clinic's website:

So why weren't face masks recommended at the start of the pandemic? At that time, experts didn't yet know the extent to which people with COVID-19 could spread the virus before symptoms appeared. Nor was it known that some people have COVID-19 but don't have any symptoms. Both groups can unknowingly spread the virus to others.

These discoveries led the U.S. Centers for Disease Control and Prevention (CDC) to do an about-face on face masks. The CDC updated its guidance to recommend widespread use of simple cloth face coverings to help prevent transmission of the virus by people who have COVID-19 but don't know it.

Some public health groups argue that masks should be reserved for health care providers and point to the critical shortage of surgical masks and N95 masks. The CDC acknowledged this concern when it recommended cloth masks for the public and not the surgical and N95 masks needed by health care providers.