Coronavirus 2019-2020 thread (no unsubstantiated rumours!)

[Rettam Stacf]

Because it most resembles the original virus with its motifs in native conformations.

The other one is live attenuated vaccine which is live viruses modified to be less virulent and dangerous. However, in some cases, they mutate and become dangerous again. Experts avoid this method nowadays.


All the hype on mRNA or Adenovirus vaccines is just hype. They're all startups whose executives want to dump stocks.

The big players like Merck are all working on inactivated or subunit vaccines. The latter of which is more difficult but safer as it only uses a small portion of the virus.

An inactivated vaccine is the quickest way to get to a working vaccine, usually.

Localizer, thanks for the explanation.

If what you said is true, then China is way way ahead in Covid-19 vaccine development because all the leading vaccines are :

• CNBG (China / 2 vaccines) and Sinovac (China) are inactivated vaccine in human clinical trial.
• Moderna (US), Imperial College (UK), BioNTech (Germany) are all mRNA vaccines
• CanSino Biologic (China) and Oxford University (UK) are Adenovirus vaccines
• No other inactivated vaccines worldwide have started human clinical trial

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[localizer]

Localizer, thanks for the explanation.

If what you said is true, then China is way way ahead in Covid-19 vaccine development because all the leading vaccines are :

• CNBG (China / 2 vaccines) and Sinovac (China) are inactivated vaccine in human clinical trial.
• Moderna (US), Imperial College (UK), BioNTech (Germany) are all mRNA vaccines
• CanSino Biologic (China) and Oxford University (UK) are Adenovirus vaccines
• No other inactivated vaccines worldwide have started human clinical trial

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Yes, but the virus undergoes conformational changes as part of its immune evasion abilities that makes it hard for vaccine development. Special techniques might be necessary for this vaccine.

China also has the problem of not having many patients to test the vaccine on.

 

[Rettam Stacf]

Yes, but the virus undergoes conformational changes as part of its immune evasion abilities that makes it hard for vaccine development. Special techniques might be necessary for this vaccine.

China also has the problem of not having many patients to test the vaccine on.

Agree. China need to quickly work out agreements on Phase 3 clinical trial with other countries that are still under intense Covid -19 infection. Countries like Russia, some EU members and South American or African countries are appropriate.

But China has to be careful not to cooperate with certain countries that cannot be trusted to protect China's trade secrets and will likely pass them on to another country to curry favor.

 

[manqiangrexue]

Any inactivated vaccine is most likely to work.

We've got to be careful, though. I previously thought so too, that this would be straight forward and you wouldn't even need a control group but that turned out it would be a really bad idea because safety is actually a big concern here. There are reports that COVID-19 patients with higher antibody titre leading to cytokine storm in their lung tissues suffer worse outcome. They've seen this in both SARS and MERS vaccine candidates and call it antibody-dependent enhancement, with the enhancement referring to enhancing disease severity. In those cases, vaccination led to greater lung damage when the patient contracted the virus. So due to the similarity between the 3, it's almost guaranteed that this needs to be paid attention to in SARS-CoV-2 as well.

Ricke, D., & Malone, R. W. (2020). Medical countermeasures analysis of 2019-nCoV and vaccine risks for antibody-dependent enhancement (ADE). Available at SSRN 3546070.

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[localizer]

We've got to be careful, though. I previously thought so too, that this would be straight forward and you wouldn't even need a control group but that turned out it would be a really bad idea because safety is actually a big concern here. There are reports that COVID-19 patients with higher antibody titre leading to cytokine storm in their lung tissues suffer worse outcome. They've seen this in both SARS and MERS vaccine candidates and call it antibody-dependent enhancement, with the enhancement referring to enhancing disease severity. In those cases, vaccination led to greater lung damage when the patient contracted the virus. So due to the similarity between the 3, it's almost guaranteed that this needs to be paid attention to in SARS-CoV-2 as well.

Ricke, D., & Malone, R. W. (2020). Medical countermeasures analysis of 2019-nCoV and vaccine risks for antibody-dependent enhancement (ADE). Available at SSRN 3546070.

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Yes, but so far we've yet to see repeated infections as a problem. That is a good sign that ADE is not contributing, at least not yet, maybe some seasons later.

 

[Intrepid]

Yes, but so far we've yet to see repeated infections as a problem.

The virus lives on for weeks in the body of supposedly recovered people. However, these no longer have symptoms and are not infectious. They are only tested positive occasionally.

 

[Intrepid]

Duisburg is not far from where I live. 35 container trains from China arrive there every week.

In the last few weeks the number was 50 trains arriving every week.

 

[localizer]

Vaccines for a single disease come in many forms after decades of development.

We all aim for subunit vaccines due to its safety and ability to be mass produced.


We can't do attenuated vaccine for covid due to old people being most vulnerable to the disease.

 

[vesicles]

Any inactivated vaccine is most likely to work.

Well, whether inactivated or attenuated, it’s a case-by-case thing. Some of most effective vaccines are derived from attenuated viruses. Measles and chickenpox vaccines are good examples.

Inactivated viruses are dead viruses, thus generating weaker immune responses in people (even if you use the whole virus). You might have to inject multiple doses to get your body to generate enough antibodies.

Attenuated viruses are actually more preferable in many cases because they are live viruses. Most of the times, a single dose is enough for healthy people to generate enough immune responses. Of course, the drawback would be that the live virus might be too strong for some people with immune issues and they might suffer some side effects.

 

[Rettam Stacf]

China building secure facilities to fast track coronavirus vaccine production

• Four of the five Chinese candidates are inactivated vaccines – a technique that involves killing the virus so that it cannot cause a serious infection but does stimulate an immune response and requires secure facilities.
• The other Chinese vaccine, and five developed in other countries, are using genetic techniques that need lower levels of biosecurity because the actual Sars-CoV-2 virus is not used in the production process.
• Two CNBG subsidiaries – the Beijing Institute of Biological Products and Wuhan Institute of Biological Products – have designed inactivated vaccines that are undergoing phase 2 trials.
• “The facility in Beijing has been completed and is in the process of qualifying for certification. The annual production capacity will be 100 million doses. The workshop in Wuhan has finished building the main structure … Its annual production capacity will be 80 million doses,” Yu said.
• The facilities will have a biosecurity rating of 3, the second highest level, because Sars-CoV-2, the virus that causes Covid-19, is highly pathogenic and will need a secure environment if it used to make the vaccine.

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