[hamdani yusuf]

....like a live animal, perhaps? Cheap, self-replicating with just enough variability to be a useful test, and a very good model of a live animal.

Preferably those with similar physiology as humans.
Something safe for tardigrades may not be safe for humans.

[Bored chemist]

Something safe for tardigrades may not be safe for humans.

Yes, and of course.
Something safe for organoids may not be safe for humans.

So, as Alan said, there's not much point testing vaccines on them, is there?

[hamdani yusuf]

Something safe for tardigrades may not be safe for humans.

Yes, and of course.
Something safe for organoids may not be safe for humans.

So, as Alan said, there's not much point testing vaccines on them, is there?

When the uncertainty is high, such as in early stages, simpler systems can be used for test. If it's promising, then increase the complexity step by step to resemble a more complete human body.

[Bored chemist]

When the uncertainty is high, such as in early stages, simpler systems can be used for test. If it's promising, then increase the complexity step by step to resemble a more complete human body.

What do you think they currently do?
Do you not think they worked that out already?

[acsinuk (OP)]

We have vaccines that work and limits the damage that Covid can inflict on human cells.  We were slow in issuing the vaccine but must now vaccinate the whole world. 
No point in putting your head in the sand like the Kiwis and Aussies are doing!!  Isolation can not work in the long term..

[Bored chemist]

No point in putting your head in the sand like the Kiwis and Aussies are doing!! 

That's not what they are doing.
And, whatever they are doing, it works.
Look at their death rates.

We should be copying them.

  Isolation can not work in the long term..

That's not what it is for.
It's a short term  measure which actually works. And you do that while you get your population vaccinated.

If you are successful, you get a vastly lower death rate- and they have.



Why are you criticising one of the big success stories?

[alancalverd]

Preferably those with similar physiology as humans.

Like a human, for instance? There wouldn't be much point in testing an anti-zoonotic vaccine on a mammal that tolerates the zoonosis. Thalidomide was deemed safe after testing on rabbits.

[alancalverd]

We were slow in issuing the vaccine

Less than a year from problem to solution, compares very well with smallpox or polio, thanks to a very rapid system for approving and monitoring tests. Only politics and stupidity have stood in the way.

[hamdani yusuf]

Preferably those with similar physiology as humans.

Like a human, for instance? There wouldn't be much point in testing an anti-zoonotic vaccine on a mammal that tolerates the zoonosis. Thalidomide was deemed safe after testing on rabbits.

Eventually, the new vaccines must be tested on humans in experimental setup, before they are released to public.
The problem is how to minimize risk before they are tested on human subjects. You can test on animals which are closely resemble humans physiologically, such as chimpanzee. The more similar they are, the accuracy would be better, and less risk for human subjects. Genetically modified chimpanzee with some human genome would be more accurate. But that would raise concerns from ethics committee.
That's where organoids may help. The ethics committee just have to draw the limit, how complete the organoid system can be to be approved as medical test subject.

Another option is to build an accurate and precise computer model to simulate human physiology, and how it will react to exposure of various substances. Alphafold can be seen as a starting point. I discuss the importance of building an accurate, precise, and relevant virtual universe in another thread.

[hamdani yusuf]

When the uncertainty is high, such as in early stages, simpler systems can be used for test. If it's promising, then increase the complexity step by step to resemble a more complete human body.

What do you think they currently do?
Do you not think they worked that out already?

Precisely. The question would then be: why you said this?

there's not much point testing vaccines on them, is there?

[hamdani yusuf]

Another good news related to current pandemic.
https://scitechdaily.com/highly-potent-covid-treatment-new-nanobodies-stop-sars-cov-2-and-its-dangerous-variants/

By Max Planck Institute August 4, 2021

Coronavirus Nanobodies Alpacas
The figure shows how two of the newly developed nanobodies (blue and magenta) bind to the receptor-binding domain (green) of the coronavirus spike protein (grey), thus preventing infection with Sars-CoV-2 and its variants. The nanobodies originate from alpacas and are smaller and simpler than conventional antibodies. Credit: Max Planck Institute for Biophysical Chemistry

Göttingen researchers have developed mini-antibodies that efficiently block the coronavirus SARS-CoV-2 and its dangerous new variants. These so-called nanobodies bind and neutralize the virus up to 1000 times better than previously developed mini-antibodies. In addition, the scientists optimized their mini-antibodies for stability and resistance to extreme heat. This unique combination makes them promising agents to treat COVID-19. Since nanobodies can be produced at low costs in large quantities, they could meet the global demand for COVID-19 therapeutics. The new nanobodies are currently in preparation for clinical trials.

Antibodies help our immune system to fend off pathogens. For example, the molecules attach to viruses and neutralize them so that they can no longer infect cells. Antibodies can also be produced industrially and administered to acutely ill patients. They then act like drugs, relieving symptoms and shortening recovery from the disease. This is established practice for treating hepatitis B and rabies. Antibodies are also used for treating COVID-19 patients. However, producing these molecules on an industrial scale is too complex and expensive to meet worldwide demand. Nanobodies could solve this problem.

Scientists at the Max Planck Institute (MPI) for Biophysical Chemistry in Göttingen (Germany) and the University Medical Center Göttingen (UMG) have now developed mini-antibodies (also known as VHH antibodies or nanobodies) that unite all the properties required for a potent drug against COVID-19. “For the first time, they combine extreme stability and outstanding efficacy against the virus and its Alpha, Beta, Gamma, and Delta mutants,” emphasizes Dirk Görlich, director at the MPI for Biophysical Chemistry.

At first glance, the new nanobodies hardly differ from anti-SARS-CoV-2 nanobodies developed by other labs. They are all directed against a crucial part of the coronavirus spikes, the receptor-binding domain that the virus deploys for invading host cells. The nanobodies block this binding domain and thereby prevent the virus from infecting cells.

“Our nanobodies can withstand temperatures of up to 95 °C without losing their function or forming aggregates,” explains Matthias Dobbelstein, professor and director of the UMG’s Institute of Molecular Oncology. “For one thing, this tells us that they might remain active in the body long enough to be effective. For another, heat-resistant nanobodies are easier to produce, process, and store.”

Single, double, and triple nanobodies
The simplest mini-antibodies developed by the Göttingen team already bind up to 1000 times more strongly to the spike protein than previously reported nanobodies. They also bind very well to the mutated receptor-binding domains of the Alpha, Beta, Gamma, and Delta strains. “Our single nanobodies are potentially suitable for inhalation and thus for direct virus neutralization in the respiratory tract,” Dobbelstein says. “In addition, because they are very small, they could readily penetrate tissues and prevent the virus from spreading further at the site of infection.”

A ‘nanobody triad’ further improves binding: The researchers bundled three identical nanobodies according to the symmetry of the spike protein, which is comprised of three identical building blocks with three binding domains. “With the nanobody triad, we literally join forces: In an ideal scenario, each of the three nanobodies attaches to one of the three binding domains,” reports Thomas Güttler, a scientist in Görlich’s team. “This creates a virtually irreversible bond. The triple will not let release the spike protein and neutralizes the virus even up to 30,000-fold better than the single nanobodies.” Another advantage: The larger size of the nanobody triad expectedly delays renal excretion. This keeps them in the body for longer and promises a longer-lasting therapeutic effect.

As a third design, the scientists produced tandems. These combine two nanobodies that target different parts of the receptor-binding domain and together can bind the spike protein. “Such tandems are extremely resistant to virus mutations and the resulting ‘immune escape’ because they bind the viral spike so strongly”, explains Metin Aksu, a researcher in Görlich’s team.

For all nanobody variants – monomeric, double as well as triple – the researchers found that very small amounts are sufficient to stop the pathogen. If used as a drug, this would allow for a low dosage and thus for fewer side effects and lower production costs.

[sceptic-eng]

Hamdani,  It has been several months since your most interesting post.  What progress has been made on developing a pill from Alpacca nanobodies as most people are fedup with Covid?

[sceptic-eng]

Well, it appears that the possible new treatment may not materialise; but we are already 90% vaccinated and herd immune to Covid, so what can we do now?  Possibly we should  consider :-     
1]  Admit that we are not God and cannot stop viruses mutating.

2]  Provide vaccinations to third world counties and develop Covid booster tablets to treat variants

3] Stop testing and track & trace completely as both are causing public anxiety and panic unnecessarily.

4]  Only consider lock-downs only when hospital ICU departments reach 50% Covid patients.

[evan_au]

we are already 90% vaccinated and herd immune to Covid

That was pretty true for Delta.
Preliminary data on Omicron suggest that it is:
- about twice as infectious as Delta,
- and our vaccines are less effective than on Delta (70% effective straight after a booster for omicron, vs 90% effective straight after a booster for Delta)

That suggests we would need very high vaccination rates to get herd immunity for Delta.
Back of the envelope calculation:
- Assume R₀ for omicron is 14 (nearly as bad as measles, at around 16)

For herd immunity, an infected person would need to come into contact with at most 1 susceptible individual, on average.
- IF the vaccines were 100% effective, that means 13/14 people would be vaccinated, or 93%
- Assuming the Booster shot wanes to 50% effective after 6 months, we would need 27/28 people vaccinated, or 96% triple-dosed

In a few more weeks, we should know more about severity of disease from Omicron.
- If the severity is less than Delta, AND the vaccines reduce severe disease, public health authorities may decide to let it run its course.
- I will still be taking my mask with me when I go out...
 

[alancalverd]

The secondary problem may be more significant than the primary one.

Even if omicron turns out to be less lethal than its predecessors, increased infectivity means that medical services can be swamped by "possibles", to the detriment of patients suffering from other diseases and injuries.

Furthermore, self-isolation of known contacts reduces the capacity of those services to handle anything: if one member of a team tests positive, you have to stand the entire team down. Cancelling football matches and brass band gigs (I speak from current experience of the latter) is an annoyance, but suspending a surgical team is really bad news.   

Within 60 years, Man had advanced from 30 seconds' powered flight to making round trips to the moon. We eliminated smallpox by quarantine and compulsory vaccination of travelers. Ebola is pretty well contained to a few endemic areas. What's gone wrong with the world in the face of COVID? 

[sceptic-eng]

Alan,   
What needs to be addressed is the requirement to self isolate if you have been near to an infectious person.  This is causing many sportsmen in particular to miss fixtures unnecessarily.  If a covid test then shows them clear then let them play and leave the team medics to keep an eye on them.

To me, everyone is infectious anyway and is carrying the virus but because they have been vaccinated do not develop the flu. Isolation for me is totally unnecessary unless you have tested positive to covid in which case it should be mandatory to stay at home and is common sense anyway.
Medical staff should be the very first to receive any vaccinations and booster treatment and again they should not self isolate unless they have a positive covid test result.
 If we were to stop public testing and issuing the results that would help immeasurably to stop the media hype which is causing so much anxiety and misery to everyone..

[Bored chemist]

What's gone wrong with the world in the face of COVID? 

Politicians who think making a fast buck is more important than maintaining the health of the population.
It's hard to imagine why anyone voted for them.

[Bored chemist]

This is causing many sportsmen in particular to miss fixtures unnecessarily. 

Who cares?

[evan_au]

everyone is infectious anyway and is carrying the virus

Speak for your own country.

Australia is an island, and managed to prevent widespread infection by quarantine and test/trace and mask-wearing practices, plus lockdowns.
- So the population had very low levels of natural immunity,
- but high levels of vaccination
- So they decided to relax all the rules for Christmas

...And then Omicron arrived!
- Extremely infectious
- Natural immunity is not very effective against infection
- Vaccination is not very effective against infection

So now many of the restrictions ae back on...
- Intentionally, eg mandating  mask-wearing in shops
- or accidentally: Internal borders have reopened, but so many aircrew were listed as close contacts that they could only staff half of the planes.

[alancalverd]

I saw a brief TV interview with a spokesman for a European country - was it Austria? - who said that their national health service would charge the full cost of treatment to anyone presenting with COVID who was eligible for free vaccination but had not accepted it. SImple, brilliant response to antivaxers.