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Comment by rlpb | Hacker News Reader

What I think really matters for most people is not to find out whether they have covid or not, but whether they are infectious or not. I'd really like to see research (any at all!) into how effective different test methods are at predicting infectiousness and am disappointed that this never seems to get addressed.

Because who cares if you're asymptomatic but your viral load is low and you're unlikely to infect others? If lack of viral load is the reason that the test is a false negative but that's also correlated with low likelihood that you can infect others, then this understanding is not useful. The test still did it's job for what people needed it for.

The full article does not seem to be publicly accessible, so I'm not sure if my comment is already covered.

View on HN

It was researched and the results were beyond poor, which is why you never heard about them.

IIRC ~75% of PCR positive samples couldn't have any virus cultured from them at all. Viral culturing isn't easy, but PCR tests can trigger on destroyed virus, so it's not a surprise that you can't get replicating virus out of many such samples especially at CT>40.

But even if you can grow virus, that doesn't mean someone is infectious. To determine that the ground truth is contact tracing and followup. But this showed that many people who were clearly sick with COVID never infected people they were in close contact with. Even within the home, most cases did not transmit, I think. I got direct experience of this when my wife got COVID and was sick for a couple of weeks, I was then quarantined by the government at home but never got sick. How this could happen was never officially explained.

This reveals one of the core scientific problems with the epidemiological simulations that were driving policy: they assumed infection is a one-way event i.e. 100% pre-existing susceptibility. I infect you, because I'm sick, you never were when we get close together we roll a dice and if it comes up 3-6 then you get infected too. This isn't how it works in reality. People's immune systems differ significantly and some are just stronger than others. To be infected I have to be infected but you have to be susceptible. The COVID models basically ignored this and assumed a homogenous population. When adjusted to reflect a more realistic heterogeneous population herd immunity thresholds went down a lot:

https://www.medrxiv.org/content/10.1101/2020.04.27.20081893v...

This research wasn't merely unnoticed, it was actively suppressed. Journals refused to publish it because, "Given the implications for public health, it is appropriate to hold claims around the herd immunity threshold to a very high evidence bar, as these would be interpreted to justify relaxation of interventions, potentially placing people at risk."

https://twitter.com/mgmgomes1/status/1291162358962937857

I've read several of your responses here, and thanks for the info, but I have to say, your tone comes off as "I know better and would have been more sensible if I were in charge."

When you're in the heart of an epidemic that's going to kill millions, you err on the side of caution. Quarantining you at home, for example, makes sense when you're dealing with a deadly disease and you don't know enough to know you're not contagious.

Again, thanks for the info, but "lessons learned" should generally be left to the people who will have to deal with the next pandemic, especially since (I'm betting) they won't express their lessons learned as confidently as you are.

Everybody gets a say in “lessons learned”. Not just a bunch of cherry picked doomsday epidemiologists. The “experts” were phenomenally myopic in their focus and would be in “lessons learned” as well.

There is far more to life than the prevention of exactly one very specific respiratory illness. If you leave it to only the “experts” the only lessons you’ll get will be so narrowly focused as to be completely useless.

“Experts” never should have been allowed to directly drive public policy. Public policy is a holistic exercise focusing on the big picture, not just one very tiny myopic thing.

An entire generation of kids will grow up forever scarred thanks to the myopic, hysterical actions of these “experts”.

"experts" keep your plane in the air, your water safe to drink, your electricity supply consistent and steady, and on and on.

Putting scare quotes around the word "experts" says more about you than the experts.

I'll use scare quotes all day long to describe the "experts" who pushed all that nonsense covid public policy. I didn't vote for them. They did nothing to earn my respect. I was just told I had to shut off my brain and follow their divine edicts no matter what nonsense they spouted. And if I didn't agree with what they said, I was labeled an alt-right wacko grandma killer.

These covid "experts" lied, manipulated the narrative, hid data, played politics, ignored data, and coerced media and big tech to play along. They silenced and attempted to discredit any colleague who went against their narrative--no matter how qualified or expert that colleague was.

I trust all kinds of experts from lawyers to water quality folks. Experts are always needed. But once you start lying and bending the truth the way the covid "experts" did... you lose the right to be considered an expert.

Nobody gets to tell me or anybody who gets to be an actual expert. That title is earned, not pushed by some authority figure and a bunch of hysterical people on social media.

I find it depressing how many people still buy into the narrative these "experts" pushed. It has nothing to do with tribalism or politics--these "experts" fucked up big time and caused incalculable damage to society that will haunt us all for decades to come. In short, Covid "experts" can rot in hell. And mark my words, what I just wrote will become the mainstream opinion soon enough.

You and I were told by “experts” that amalgams of B+ rated mortgages could be, in combination, AAA securities.

You and I were told by “experts” that SH had WMD and that the brief war would cost about 400M.

Yes, I hope my scare quotes do, indeed, say something about me.

The fact that the weather forecast is sometimes wrong doesn't mean you should listen to your best friend about whether to pack an umbrella. Demanding that experts be right all the time is unrealistic. And damning all experts because some used their authority to lie is sub-optimal.

Then perhaps those “experts” shouldn’t be making broad, far reaching, incredibly costly public policy? Especially ones as incredibly destructive as what was enacted for covid.

All the crap these “experts” pushed was the exact opposite of what was in tons of different pandemic plans. It was all unproven and untested. Making us all in unconsenting research subjects.

Policy is extremely different from engineering. Would you accept “policy experts”?

I don't expect policy experts to have all the answers, just as I don't expect physicists to be able to reconcile quantum theory with gravity. Some fields are harder to predict than others.

> Quarantining you at home, for example, makes sense when you're dealing with a deadly disease

Intuitively yes, in reality no. It was known by March 2020 that quarantines had no effect because of the outcome of trying it on the Diamond Princess, a sealed environment where quarantine could be perfectly enforced. That didn't stop SARS-CoV-2 spreading between cabins and causing COVID apparently at random, i.e. it'd propagated everywhere but not everyone was susceptible. This knowledge was never incorporated into health policy. The same thing had been found during the SARS-1 outbreak in Hong Kong, where it was able to move between apartment blocks separated by a garden on air currents. The quarantine within the origin apartment block didn't work due to airborne transmission, something the WHO denied was possible.

It was even known before 2020. Public health planning before this time said clearly not to use mass testing and mass quarantines because they don't work. This was torn up once COVID started.

> your tone comes off as "I know better and would have been more sensible if I were in charge."

Frustrated, yes, I know how it sounds.

The COVID response was deeply flawed from the start, and in ways that were obvious even to outsiders. I was writing about the impossible claims being made for PCR tests and the history of failed epidemic models in Spring 2020, but I don't think I'd have done better if I ran the WHO. That's because the incentives and structures such people operate under are terrible, and apparently overwhelmingly strong.

Consider this article from 2010 [1]. Der Spiegel investigated the Swine Flu "mass hysteria" and stated that the world clearly overreacted. Reporting on the WHO, "At any rate, efforts to downplay the risks were unwelcome, and the WHO made it clear that it preferred to base its decisions on a worst-case scenario. "We wanted to overestimate rather than underestimate the situation," says Fukuda."

Given everything that happened since I'm really convinced that the right way to handle a pandemic is just to let individuals and their doctors get on with it. Academics and NGOs can make recommendations if they want, but giving these people power is a bad idea. Central health planners are incentivized to maximally over-react, every single time. No lessons are ever learned, and why would any be? They have absolute immunity from accountability and consider interventions to be cost free. That is corrupting. What happened with COVID will happen again.

[1] https://www.spiegel.de/international/world/reconstruction-of...

The Diamond Princess was sealed, but impossible to effectively quarantine since the cabins have shared air circulation. That was back when people were still hoping it wasn't airport.

Again, there are people who get paid to spend all their time determining whether, for example, overestimation is worse or underestimation is.

It is an absolute certainty that the response to covid was suboptimal. Apart from how complex the situation and the response was, just given that responses varied widely from region to region guarantees that most were not perfect.

But while it's certainly possible to nitpick some aspect or another of the response, to jump from that to therefore you (or I) know better than the people being paid to do nothing but study the situation and learn from the outcomes, is as conceited as looking at the Challenger explosion and saying, "Clearly there was a problem with the O-rings, therefore I know better how NASA should be run."

I didn't mean to attack you with my comment -- I just wanted to inform you of how your tone seemed in case you were unaware. It seems that you're not only aware, you think your tone is justified. So good for you, enjoy your confidence.

You make the same argument in another post, will reply once.

Your examples of experts you trust are all engineers, not public health scientists. Air disasters, power outages and rocket explosions are immediate, visible and concrete failures. You can't consensus your way out of a plane crash. If a plane goes down ordinary people demand serious answers and because plane travel is run by the private sector the operators are all very incentivized to cooperate with a real investigation, in order to reassure the public it won't happen again. The investigations into these failures are very deep, very real, root cause what went wrong and generate concrete changes.

Scientists aren't operating in the same environment. Many people use as a test of scientific competence "do you agree with other scientists" and nothing else, which is circular reasoning. When scientists fail there's a tendency for them to argue that oh well the situation was complex, lots of unknowns, did the best we could, consensus of experts etc. People are trained to never argue with scientists so they can do this.

Engineers don't get the same privilege. Saying "the experts decided it" is worth nothing to governments, the media or the public if your oil drilling ship just sank.

> It seems that you're not only aware, you think your tone is justified

I encourage you to play the other side of this argument for a while. I've been called all kinds of absolutely awful things by people I used to respect. Why? Because I dared to question or examine things myself. I guess I was just expected to shut up and listen to "the experts" even if I found their edicts to be completely useless, unethical, immoral, and not even close to being driven by data. I've been banned, blocked, and called "dangerous" just for linking to public data hosted on a government website.

Somewhere I read "consensus"... well, there was absolutely no consensus. Any critic, no matter how qualified, was immediately discredited by those in power. Covid policy was completely one-sided the entire time.

So, I'm kinda sorry but not really sorry about my tone. Those of us who had to suffer through 3 years of hell thanks to "the experts" intentionally painting us as heartless alt-right grandma killers... well we are kinda pissed. We've all heard every argument you write. We heard it for three years. And we believe it is wrong; ethically, morally, and legally.

And we have a complete right to that opinion. Because public policy is not based on "experts" or "the science" but on opinion and values. And quite frankly, the values that drove the lockdowns and all the other nonsense covid theater are, in my opinion, bad...even evil.

The values that drove lockdowns and such expose some of the absolute worst aspects of humanity--arrogance, hubris, and tribalism. Modern humans think they are way more advanced than people thousands of years ago, but based on our reactions to covid, I'd say we have the same archaic superstitions our ancestors had back when we all lived in caves.

Anyway, I hope this helps you understand where those of us with a difference of opinion come from.

Sweden seemed quite sensible. Maybe we should just copy them next time.

> I got direct experience of this when my wife got COVID and was sick for a couple of weeks, I was then quarantined by the government at home but never got sick. How this could happen was never officially explained.

It seems you have been doing in-depth research about Sars-Cov-2/Covid-19, how did you miss the secondary attack rate/household infection rate? It used to be one of the crucial measures of transmission in early 2020, and has been studied for every variant ever since.

What I don't understand is this jump between the complexity of the situation and the simplicity of your conclusions. You go into great length to point out the shortcomings of PCR tests or that 100% susceptibility is an unrealistic modelling assumption, but your interpretations/conclusions are often blanket statements like

> This reveals one of the core scientific problems

> This research wasn't merely unnoticed, it was actively suppressed.

I notice that in your conclusions you tend to lump together very heterogeneous groups, like "scientists", "the media", "government", "the people who run healthcare" - and "they" seem to be responsible for the shortcomings? I find it very puzzling. E.g. scientific consensus is rarely clear-cut, but you will find plenty of papers/opinions arguing for and against something. Same with governments, there are some 200 countries and "they" followed very different policies. Wouldn't it be more convincing to present both evidence for and against a certain hypothesis?

I referenced the SAR in the post you're replying to (not under that name). Measuring that it's quite low isn't an explanation of why that happens, or an incorporation of that fact into policy.

I get what you mean about consensus but scientific consensus is by definition clear cut, it's supposed to mean 100% agreement. Often something is presented as a scientific consensus when it's really not, rather, people who disagree are being ignored or blocked from publishing.

During COVID a lot of things were presented to the public as if it were 100% obvious and agreed with by every specialist, then policy was made on that basis. You couldn't just disagree with government mitigations and ignore them, they were enforced by law and this was justified by the idea that anyone who disagreed with their effectiveness was a misinformation-addled rube who had to be forced for the good of everyone else. People who pointed out data or papers that disagreed with this supposed consensus were fired or banned from social media to try and maintain this illusion of universal agreement.

> there are some 200 countries and "they" followed very different policies

Did they? I'm pretty sure virtually every (rich) country all imposed mass testing, quarantines, mask mandates, lockdowns and mass vaccinations. Other than Sweden famously rejecting lockdowns, which countries didn't do these things? Policy was globally homogenous because the public health community is global and their methods don't really vary. Tegnell was the exception that proved the rule.

> Often something is presented as a scientific consensus

> During COVID a lot of things were presented to the public as if it were 100% obvious and agreed with by every specialist

Who is it that presents things to the public? Who are "they"? Who is "the media"? At least in the country I live in different journalists/writers/bloggers had very different opinions and they changed significantly over time. You could even watch the scientific process in real-time: New evidence comes in, people update their beliefs.

> scientific consensus is by definition clear cut

> maintain this illusion of universal agreement.

> Policy was globally homogenous

We can agree or disagree whether there are these groups that all act in unison, what I want to point out is that you need these homogenous groups for your argument to work.

If different countries had come to similar conclusions independently, that would mean the conclusion are likely valid, no? If different journalists/experts/scientist from different countries/cultures/political backgrounds came to similar conclusions independently, that would mean the conclusion is likely valid, no?

I'm making a guess here: I hypothesise that your discontent stems from the fact that you don't want other people to tell you what to do or not to do. In particular you disagree with the concept that society is a mechanism to distribute both wealth but also burden. Does that ring a bell?

"They" means scientists. The CDC, SAGE in the UK and the equivalents in other countries. They were directly giving briefings and press conferences.

We got to watch the scientific process in real time, indeed. It consisted of new evidence coming in and nobody updating their beliefs.

> If different countries had come to similar conclusions independently, that would mean the conclusion are likely valid, no?

No. After all, that cuts both ways. Many hundreds of millions of people around the world who were fully independent of the scientific grant funding structure watched this process and came to very different conclusions. So that must be mean the conclusions are likely invalid, no?

> People's immune systems differ significantly and some are just stronger than others.

Just a nit but stronger is a weird term to describe any functioning immune system. Some genetic trade-off that makes one immune system better suited to blocking COVID infection might make it worse at something else.

> To be infected I have to be infected but you have to be susceptible. The COVID models basically ignored this and assumed a homogenous population.

And the data used to drive those models is going to be a result of a real world average across the population, so that is fine for nation level decision making.

Let’s say you’re using data from two traced cases, a case with high susceptibility (HS) family members and one with low susceptibility (LS) family members.

The HS case was in contact with 4 family members, 3 of which became infected. The LS case was in contact with 4 family members and 1 became infected.

Two infections, 50% transmission rate. That is fine for modeling and policy, unless we have some sort of a test to determine if you are HS/LS which could be used to make more granular policies.

All of this is moot considering the the different variants we never reached some magical “herd immunity” anyways.

In theory yes. In practice no. The models weren't driven by data in the way you're thinking. Go take a look at their source code if you don't believe me. COVID-Sim had ~150 parameters, virtually all of which were made up guesses. Of the rest they were computed from random things like news reports from Chinese media, friends who happened to work in hospitals, etc.

When more data did become available the models were often never updated. I reviewed the code of several models during the pandemic. Beyond having severe bugs, they also frequently used values from January in December or even well into 2021! As more data came in it became clear that the original assumptions were far too pessimistic, but epidemiology doesn't distinguish clearly between assumptions, simulation results and observational data. So they just kept using the old numbers. It got their results in the news and peer reviewers didn't care.

> All of this is moot considering the the different variants we never reached some magical “herd immunity” anyways.

Well, we don't really know why variants suddenly displaced each other so fast and so completely. It would appear that there's some kind of viral interference, in which you can't be infected with multiple respiratory viruses at once. That doesn't fit with any classical form of germ theory, but the COVID response was based on the assumption of high-school level germ theory being complete, even when collected sample data showed that couldn't be true.

> In theory yes. In practice no. The models weren't driven by data in the way you're thinking. Go take a look at their source code if you don't believe me. COVID-Sim had ~150 parameters, virtually all of which were made up guesses.

The parameter’s my region’s epidemiologists were using for their models was certainly being updated as new data became available. I even had a conversation with one of them on Reddit about it.

> Well, we don't really know why variants suddenly displaced each other so fast and so completely. It would appear that there's some kind of viral interference, in which you can't be infected with multiple respiratory viruses at once.

Eh? It is the same natural selection, competitive process at large scale and in the body.

You can be infected with multiple variants.

> How this could happen was never officially explained.

Maybe you caught Covid but went asymptomatic because your immune system is just better at handling it? (and PCR tests won't detect it because, as this story says, they miss 90% of asymptomatic cases)

This is hardly unheard of, unexpected or unexplained.

Yeah, I read that part and was like... but I remember reading & hearing pretty damn early in the pandemic that a fairly high percentage of infections are asymptomatic, and continuing to see that stated periodically and never (that I read or heard) contradicted for the whole rest of the pandemic. And sure enough, most households I know that had Covid roll through (which is, at this point, practically every household of everyone I know) played out like that—it was more common than not for at least one person in the house to never get signs or symptoms.

Right? Is that not how it went?

Yes that's how it went. That experience was very common.

It was unexpected. The models deployed to justify lockdown assumed 100% susceptibility to COVID-the-disease on the grounds that the virus was "novel". Although they had some crude notion of chance involved in transmission, they didn't have any notion that you could be heavily and repeatedly exposed to the virus and just never catch it at all. When did governments admit that this expectation had been violated, that must be a lot of pre-existing immunity? IIRC, they never did.

And what's the official explanation for how that happened? AFAIK there isn't one? There were some attempts at the edges to claim that all these people must have had symptoms, just so mild they didn't notice. But if neither you nor anyone else ever notice you got sick, then you didn't get sick using any conventional definition of sickness because disease is defined as a collection of symptoms.

> But if neither you nor anyone else ever notice you got sick, then you didn't get sick using any conventional definition of sickness because disease is defined as a collection of symptoms.

So was Typhoid Mary sick? Is an asymptomatic patient with a positive HIV test? Kary Mullis--the inventor of PCR!--says no:

> A man with gray hair and a goatee raises his hand. He says he's been HIV-positive since 1984, that he took the anti-AIDS drug AZT for a couple years but stopped. Now, he says, his T-cell count -- the number of a kind of white blood cell that is killed by HIV -- has gone way down.

> Mullis interrupts him: "Change doctors!"

> The man continues. His T-cell count is down to 150, which is usually thought of as dangerously low. He asks Mullis for advice.

> "I would say there is no evidence that I can find in the scientific literature that you should worry about HIV or your T-cell count," Mullis tells him. "If you'd stop worrying, maybe you'll be all right. You look pretty healthy to me."

https://www.washingtonpost.com/archive/lifestyle/1998/11/03/...

Do you think he gave that patient good advice?

HIV and AIDS is a good example of separating pathogen and disease. Being HIV+ isn't the same thing as having AIDS. You can have HIV+ and not be sick as the anecdote from the story indicates (14 years HIV+ without developing AIDS?).

If he's not sick, then why should he take AZT? And if Typhoid Mary isn't sick, then why can't she work as a cook?

The point is that even if you feel good now, a positive HIV test means that without treatment, you'll almost certainly die within the next 10-20 years. You can also infect others, and they'll die too. (As to the 14 years, the patient Mullis talked to was presumably some combination of lucky and/or benefiting from the AZT he'd taken previously.)

Likewise, a positive SARS-CoV-2 test meant that you'll die with p ~ 1%[1] within the next couple months. That's much less bad than HIV, and the relative benefits of treatment are much smaller; but that's spectacularly higher than baseline mortality, so the test is clearly predictive.

The concept of asymptomatic disease is well-recognized in medicine; just google the phrase. I'm not sure how Kary Mullis managed to convince so many people to reject it.

1. That's a CFR over all ages, confirmed deaths divided by confirmed positives. The IFR is of course lower, but the statement is conditioned on a positive test.

You're conflating asymptomatic with pre-symptomatic. The former means you never develop symptoms. The latter means you are about to get sick but aren't currently.

That HIV patient was indeed near-certain to be symptomatic later, but Typhoid Mary was permanently asymptomatic. That's unusual for typhoid, but for other pathogens (e.g. cytomegalovirus) most infected patients are permanently asymptomatic, with only a small minority of patients showing symptoms:

https://www.cdc.gov/cmv/congenital-infection.html

Your claims are inconsistent with at least a century of boring, uncontroversial medicine. I don't know whether you're doing it knowingly, but you're closely repeating the arguments of Kary Mullis, who was clearly smart (he invented PCR!) but not exactly reliable (he denied that HIV causes AIDS! he saw a talking, fluorescent raccoon!).

Ah, OK, I see the distinction you intended now. Thanks.

Also there was an outbreak at a Belgian Antarctic base. Incoming personel took PCR tests, tested negative and were also quarantined for 10 days in South Africa. Then they took an additional PCR test 48h before departure. Six days after arrival there was the first Covid case.

https://abcnews.go.com/Health/covid-outbreak-belgian-researc...

Of course, certain news outlets like for instance the BBC have failed to disclose these additional details.

Interesting. I hadn't heard that one. However it's happened before, in the 1980s. Some researchers who were staying at a British Antarctic base over winter were entirely isolated once the last plane left. Months later they starting coming down with colds, despite none of them being sick originally.

Back then epidemiology was a more curious field so this was investigated in some depth. Nobody had opened any new crates or done anything else that could expose fomites. There had obviously been no contact with anyone else. No source for the infection could be identified.

In the wake of this there were a couple of hypotheses which have since been forgotten:

1. Transmission from the atmosphere. There's some other work that explored the idea that influenza could travel long distances in the upper atmosphere whilst remaining viable.

It's known that SARS-like viruses can float through the air because this is how it spread between apartment blocks in a SARS-1 outbreak in Hong Kong. It's also hard to see how it could have spread on the Diamond Princess except via air ducts. Despite being called SARS-2 though, the possibility of airborne transmission was strongly denied at every point by the WHO and other health agencies, presumably because it would have invalidated the rationale for lockdown.

2. Constant low level infection that our immune systems normally keep suppressed. Then you have a bad day, don't sleep well or something else knocks you off balance and this is enough for the infection to start replicating out of control until the big guns are fired up.

There are some number of viruses that can remain latent in the human body, it is still being researched if covid can, but it is thought to be the case.

>WHAT ABOUT SARS-COV-2? CAN IT UNDERGO VIRUS REACTIVATION? >Research on SARS-CoV-2, the virus that causes the COVID-19 disease, is still ongoing. Infectious Disease specialists are studying its behavior to figure out if this virus can remain latent in the human body. Early research suggests that the virus may cause a latent viral infection, i.e., people who are believed to be cured of COVID-19 may test positive again due to reactivated virus rather than a re-infection. A person with a reactivated infection can potentially cause virus spread.

>COVID “long haulers,” especially previously healthy people who are experiencing long-term symptoms after COVID, are of special interest to scientists. Researchers are trying to figure out whether the continuing symptoms are because their bodies are unable to put the virus into a dormant state. Only time will tell if SARS-CoV-2 is truly a virus that can undergo latent viral reactivation.

#2 could hold some truth. Almost every time I have a drinking session, I develop a common cold: runny nose, maybe a little cough. Summer, winter, doesn't matter. Resolves in a day or two but it's another inconvenience on top of the hangover.

It's a true tragedy of our time that the CDC, scientific journals, and the media turned to trained epidemiologists for sophisticated pandemic risk assessments rather than random internet guys who find their truth on Twitter. /s

I was looking at [1] recently to understand omicron variant positivity length and they cite a few other papers. The article [1] is publicly available. I haven’t checked if all of the others are.

* Routsias JG , Mavrouli M , Tsoplou P , Dioikitopoulou K , Tsakris A . Diagnostic performance of rapid antigen tests (RATs) for SARS-CoV-2 and their efficacy in monitoring the infectiousness of COVID-19 patients. Sci Rep. 2021;11(1):22863. doi:10.1038/s41598-021-02197-z

* Currie DW , Shah MM , Salvatore PP , et al; CDC COVID-19 Response Epidemiology Field Studies Team. Relationship of SARS-CoV-2 antigen and reverse transcription PCR positivity for viral cultures. Emerg Infect Dis. 2022;28(3):717-720. doi:10.3201/eid2803.211747

* Korenkov M , Poopalasingam N , Madler M , et al. Evaluation of a rapid antigen test to detect SARS-CoV-2 infection and identify potentially infectious individuals. J Clin Microbiol. 2021;59(9):e0089621. doi:10.1128/JCM.00896-21

* Killingley B , Mann A , Kalinova M , et al. Safety, tolerability and viral kinetics during SARS-CoV-2 human challenge in young adults. Nat Med. 2022;28:1031-1041. doi:10.1038/s41591-022-01780-9

[1] COVID-19 Symptoms and Duration of Rapid Antigen Test Positivity at a Community Testing and Surveillance Site During Pre-Delta, Delta, and Omicron BA.1 Periods. https://jamanetwork.com/journals/jamanetworkopen/fullarticle...

> but whether they are infectious or not.

We don't have a labor and cost effective test for this, and we require the test to be done in a BSL-3 facility.

So what remains is that we need to solve public health problems with tests that produce only correlates of infectiousness. Those correlates will be necessarily imperfect, but they're all that we have to craft policy around.

The perfect home test which only detects infectious virus doesn't exist.

And I'd just like to see more published studies which actually cultured virus rather than using PCR as a proxy for infectious virus, but even that is hard to get. So many lazy scientific studies out there conflating PCR positive with virus, but there's a lot more researchers who can do PCR than researchers than have access+funding to a BSL-3 lab.

It's not just whether you are infectious but whether you will become infectious. Hardly anyone cares about covid anymore, but a year or two ago, people would often take a test before they, for example, stayed over at a relative's house.

If you take a test right before you arrive, and you stay for a couple of days, if you just caught covid the day you arrived, you'd like to know that. That's where a more sensitive test is really useful.

This is a particular problem with newer variants of covid because they multiply much faster. A very low viral load in the nose when the test is taken can turn into a lot in a matter of hours.

Anyhow all of this is fairly academic at this point because no one is taking any tests and everyone is doing big events with lots of people.

> What I think really matters for most people is not to find out whether they have covid or not, but whether they are infectious or not.

While some folks are certainly still worried about spreading the virus, for most folks it's always been about whether a positive test requires them to restrict their movement or activities (e.g. whether or not one could fly on a plane in 2020-2022).

That may be true for most, but there are many of us who interact with at-risk people (elderly parents, an immune suppressed family member, etc.) and the daily concern is whether or not I might be infectious and potentially bring harm to someone else. I don't care if I have Covid if I can't spread it to someone else.

Public service request: There are millions of Americans with compromised immune systems who are finding the current environment treacherous since most people have completely moved on. If we have an interaction with someone who is masked, it would be great if we could just mask up at least during that interaction as a courtesy. That person could be at significant risk and it does no harm to us to mask up for a few minutes to help reduce their risk even if we aren't concerned for ourselves.

Agreed, and that's why I mentioned there are certainly some folks still concerned.

Yep. I just wanted to emphasize that side of it.

I think if you go back to polls and news from the time, "most folks" only caring about legal requirements is probably a projection of your opinion and direct contacts'. Pretty sure most people were actually concerned with not infecting others, within reason (which is a different level for everyone, but still)

It sounds like you might be conflating two different issues here (being why people were taking covid tests without any symptoms, and why people were doing the superset of actions that would mitigate spreading the virus). There certainly was some overlap where folks who needed to take them for their jobs also wanted to keep people safe, but in general do you believe there were a large number of folks who were or are taking covid tests while not showing symptoms and not being required to take the tests?

Additionally, you made a huge leap in assumptions about me that simply aren't true when you assumed what my opinion is/was and how that would project. Let's keep it away from getting personal like that?

> for most folks it's always been about whether a positive test requires them to restrict their movement or activities

Sure but that problem is once removed from the real problem. The underlying reason for restrictions is infectiousness. If tests measured infectiousness accurately, rules on restrictions would follow and use those tests instead.

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