The biology of coronavirus COVID-19 - including research and treatments

I am really surprised as to why journalists and scientists aren't bothering to look whether the same thing happens after other infections and vaccinations.

The observed pattern in antibody titres is typical post-infection and not yet a cause for concern.

 

I meant to say the observed pattern, it seems my attention to detail is poor today.

 

Derya Unutmaz on the decline in antibodies post Covid-19:

https://twitter.com/user/status/1285927522350370822

 

https://www.jwatch.org/na51986/2020/07/20/characterizing-cognitive-impairment-patients-recovered

 

This seems so basic I have been wondering if I am missing something when everyone is worried about antibody levels dropping.

 

I think there are two facets to this, one is people worrying that undetectable antibodies means no immunity, and that's a misperception -- there are other components to immune memory: memory B and memory T cells, that can quickly escalate an immune response, including regenerating antibodies, to a previously encountered antigen.

But the other facet, is that disappearing antibodies make the antibody tests much less useful for estimating prevalence rates, as it means they can only really provide a snapshot of infections over, say, the previous 6 week period with any degree of certainty. Perhaps this could mean that population exposure to Sars-Cov-2 is multiples greater than community samples suggest, depending on when the pandemic started and sample date.

 

Daily Mail again, sorry, but:

Protein drug 'reversed' deadly cytokine storm in COVID-19 patients

http://www.msn.com/en-gb/health/med...9-patients/ar-BB174xSi?li=BBoPWjQ&ocid=ASUDHP

 

Moved from the spread and control thread.

A new coronavirus mutation is taking over the world. Here's what that means.

https://www.livescience.com/new-coronavirus-mutation-explained.html

It goes on to rather blind me with science a bit, but I guess quite a few people here will be able to make sense of it

 

The antibody levels aren't disappearing, they're merely dropping because the immune system has no ongoing need of high antibody levels once the infection has been dealt with. The people who are "worried" have not bothered to read or cite what happens after other infections or vaccinations. It is a case of overreacting due to ignorance. The only surprise might be that such sloppy thinking is not merely limited to certain fields.

 

I didn't know on which of the many threads to say this, but this is as good as any.

It may, or may not, be worth pointing out that whatever it was that caused the Dalston outbreak of ME in 1955, which was considered similar in many respects to the Royal Free, it apparently affected the sense of taste and smell in a similar, but perhaps not identical way to Covid.

Walis said:

Impaiment acuity of the sense of taste and smell was
present in most cases and abnormal perception of various tastes
and smells was also commonly found.

Is this common in viral illnesses?

 

Possibly for upper respiratory infection sinus type viruses or bacterial infections?

 

@chrisb

What causes abnormal sense of taste and smell?
The most common causes of smell disorders are nasal and/or sinus disease, viral upper respiratory infections, and head trauma. The most common causes of taste disorders are upper respiratory tract infections and head injuries. Other infrequent causes of both include masses in the nasal or oral passageways, endocrine problems, side effects from medications, and degenerative processes of the brain.

https://my.clevelandclinic.org/health/diseases/16708-abnormal-sense-of-taste-and-smell

 

It is not common of all viral illnesses, and tends to be specific to 'neurotropic' viruses that infect the olfactory bulb. (of course herpesviruses and enteroviruses are on that list.)

Of course if you want to go down the speculative path of betacoronaviruses...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3194943/

 

Well I've had reduced sense of taste since I had both glandular fever and then coxsackie B3 in 1980. Though weirdly a times, or rather I think it's more with just some substances, my sense of smell is SO acute and I can react to small amounts of perfume, smoke, paint etc, so it's odd but certainly my taste has never fully recovered since these viral infections.

 

New antibody mix could form 'very potent' Covid-19 treatment, say scientists

Does anyone know exactly how these monoclonal antibodies are manufactured? Do they contain mouse protein, and would it be a problem if they did?

Full Liu et al, 22 July 2020, paper here:
Potent neutralizing antibodies directed to multiple epitopes on SARS-CoV-2 spike

 

Here are some research paper links that may belong in another thread. I'm hoping an administrator will find the right place. I'm dealing with other concerns at the moment.

BGR has a description of the paper in Nature Communications which details the discovery of an RNA cap which disguises viral mRNA, defeating one defense. This led me to some more investigation about enzymes involved leading to this publication. This is a very sophisticated natural pathogen which overcomes several problems typical of single-stranded RNA viruses.

We already knew it had RNA repair mechanisms to lower the rate at which it mutates. The next problem was hijacking mRNA without setting off alarms. A DNA virus could make changes inside the nucleus, so that the cell's own machinery would produce viral RNA. Working outside the nucleus requires a different solution.

SARS-CoV-2 also infects dogs and cats, as well as several other known species, including mustelids, like minks and feliforms, like palm-civets. This is a strong indication the host species where the different sequences from bats and pangolins came together was a member of the carnivora taxonomic group. Bats and pangolins are both insectovores with substantial divergence from common ancestors with this group. Predation is a natural way for infection to pass to such species.

The sophistication we see points to a long period of adaptation to new hosts, not human manipulation. Nobody knew a great deal about these mechanisms prior to this epidemic. Genetic manipulation also leaves artifacts, which are absent.

Interfering with enzymes like nsp16, or the nsp10 it requires, opens a new path to stopping infection. A year from now we will know exactly what we needed to know last year.

 

The monoclonal antibodies are typically manufactured using novel cell culture techniques. (though in-vivo in mice is also possible, though less desirable)
Engineered antibodies can also be produced in a recombinant manner in bacterial cell culture.

As far as the actual engineering goes:
https://en.wikipedia.org/wiki/Hybridoma_technology
https://en.wikipedia.org/wiki/Fusion_protein
https://en.wikipedia.org/wiki/Phage_display
https://en.wikipedia.org/wiki/Genetically_modified_mouse
https://en.wikipedia.org/wiki/Recombinant_antibodies

These days there is a huge range of monoclonal antibodies available, most are for laboratory use and not used for therapeutic purposes.

The specific mabs in that study were made using recombinant technology in Expi293 (human based) cell culture, based on screened B-cell receptor sequences: