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The saliva stays inside the tube for that very reason. The test specifically identifies the virus, not the antibodies, again for the reason you identify.

Currently most public buildings are closed, so adding ten minutes is a big improvement relative to that. Also, it probably took them more than ten minutes to drive to work, so I don't think it's completely implausible.

Assuming everything goes to plan, how will these be staffed and manufactured at scale?

It's a fully automated solution, like an airport kiosk or a subway turnstile. Maybe I need to make that more clear?

Yes, I didn't get that from the essay. It's a fully automated scanner that can be operated by the person being tested?

People hop over subway turnstiles all the time. It would have to be more secure than that to make me feel safe once I'm inside.

You could have security guards with masks at every entrance. But if even one person with COVID-19 gets past security, you could start an outbreak.

How far along is development?

I might be misreading your comment, but I don't think the blog is promoting antibody testing? It sounds like the blog is about a method of detecting viral particles directly, perhaps using an immunoassay based on the wiki for SPR, but not to test for antibodies directly.

And in terms of medical records laws, the regulatory environment has loosened so quickly with the advent of this virus that I'm sure regulators and legislators will be favorable to making it easier for the company if the test demonstrates the appropriate sensitivity and specificity in clinical trials. People are getting reimbursed for sending emails to patients, health visits done over zoom, would have been impossible to imagine this level of regulatory flexibility just six months ago.

A shopping mall could have screeners at literally every entrance, and there are sometimes dozens of entrances at a shopping mall.

Even then, traffic might be reduced, but it would be enough traffic for something like regular life to resume. Some businesses would be able to survive, even if not all.

* IDEA *

They could also do checks in the parking lot of any business. You drive up, someone comes out to start the process and marks down your license plate. After 10 minutes they return to your car and tell you your results.

This way nobody is standing in long lines possibly spreading the disease to each other. And it scales well to large numbers of people being tested simultaneously.

There would be a lag time of 10 minutes, but throughput would be nearly the same as before COVID.

Not to quibble too much with most of your criticism, but this one seems minor and trivially solved:

> this does not allow the screener to differentiate between "has COVID-19" and "had COVID-19"

As a policy matter, this doesn't rule out the use of the test in a pandemic management protocol at all, it just changes how it needs to be administered. For example it might require that people who are antibody-positive have a standardized note confirming recovery (in Contagion, this was a cute electronic bracelet).

The critical requirement is that we detect unknown positives, and this test would do that.

I also don't think this particular test is an antibody test? It seems that this test detects viral particles based on:

"The most proven and ready to scale technology is based on surface plasmon resonance. It’s able to detect even a very small number of viral particles, which is very important because we want to detect everyone who is contagious"

(6th paragraph in the "A third solution" paragraph)

> people who are antibody-positive have a standardized note confirming recovery

How do you prove recovery if you were never proven sick first?

As an example, I had all the symptoms of Covid in late February, the same severity many people in my age group described, yet was never tested since our health authority dropped the ball and claimed community transmission wasn't a thing back then.

If I tested positive for antibodies, would I get treated like someone newly infected? The only way to prove recovery is to prove you have antibodies and don't have the virus, so we'd essentially have to test every single member of society.

There are different subtypes of antibodies that you test, some that emerge early in infection and others that emerge later. The current understanding is that the later emerging antibodies being positive generally indicates that you are not only recovered but also immune from the virus and can donate your own convalescent plasma to be used as a drug for people with the infection. If you test positive for early antibodies you are assumed to still be undergoing the course of the infection.

Test positive. Wait 14 days. Now you're positive clean.

Also test igg instead of igm, and data suggests igg is more reliable anyway

And is someone going to verify I waited 14 days? Also, why should I have to if I already am clean?

> And is someone going to verify I waited 14 days?

Sure, good idea.

> Also, why should I have to if I already am clean?

Oh, you don't have to. You can just stay at home like now.

I mean, my reaction is certainly on the "let us know when you start scaling out a quite accurate test" side of things, but I don't understand the point of declaring that it can't work.

Especially based on assumptions.

The petty whinging in your third paragraph is basically ridiculous. Imagine, waiting 10 or 20 minutes a day for a few months to help save millions of life-years.

People don't even observe yield signs reliably. You think everyone on earth is going to suddenly obey testing requirements?

If there's a fast, accurate, cheap test, I don't think compliance is going to be a big issue.

There will be a few people who have some issue with regular testing, the vast majority of people will be happy to have a tool that works.

> antibody assays; this does not allow the screener to differentiate between "has COVID-19" and "had COVID-19"

It does if it's an IgM test - IgM is only around during the illness. However, it takes a while to come up, so it can't tell you if someone is presymptomatic, at which point they are highly infectious.

Some of the assays do appear to functionalize the surface to directly bind and detect viral particles. I have some familiarity with SPR but haven't used it and not to detect viruses (otherwise experienced with surface science).

What they’re describing is an antigen test, not an antibody test. It tests directly for part of the virus, not an immune response, so it’s more a replacement for the existing PCR testing.

That said, I have some serious doubts about the particular mechanism being used here being ready for $1/test within say the next year or two. It’s been studied for a few decades and while there has been some promising progress, this would be the first saliva viral antigen test using this technology. It seems a bit like trying to solve global warming by bringing fusion generators to market. I have doubts it will be deployable before a vaccine, let alone more conventional and boring antigen rapid diagnostic tests that we have developed for a wide array of viruses.