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Modeling coronavirus spread, or why are there different numbers of expected deaths?

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  • #31
    Worthy note when comparing viruses: MERS is a Middle East virus transmitted to humans from camels, and a very low threat beyond the Middle East.

    SARS origin is a specific wild animal civiet in China.
    Glendower: I can call spirits from the vasty deep.
    Hotspur: Why, so can I, or so can any man;
    But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

    go with the flow the river knows . . .

    Frank

    I do not know, therefore everything is in pencil.

    Comment


    • #32
      Excellent preliminary research on the origins of this variety of coronavirus. Please note the bold:


      Source: https://www.nature.com/articles/s41591-020-0820-9



      Theories of SARS-CoV-2 origins

      It is improbable that SARS-CoV-2 emerged through laboratory manipulation of a related SARS-CoV-like coronavirus. As noted above, the RBD of SARS-CoV-2 is optimized for binding to human ACE2 with an efficient solution different from those previously predicted 7,11. Furthermore, if genetic manipulation had been performed, one of the several reverse-genetic systems available for betacoronaviruses would probably have been used 19. However, the genetic data irrefutably show that SARS-CoV-2 is not derived from any previously used virus backbone 20. Instead, we propose two scenarios that can plausibly explain the origin of SARS-CoV-2: (i) natural selection in an animal host before zoonotic transfer; and (ii) natural selection in humans following zoonotic transfer. We also discuss whether selection during passage could have given rise to SARS-CoV-2.

      1. Natural selection in an animal host before zoonotic transfer

      As many early cases of COVID-19 were linked to the Huanan market in Wuhan1,2, it is possible that an animal source was present at this location. Given the similarity of SARS-CoV-2 to bat SARS-CoV-like coronaviruses2, it is likely that bats serve as reservoir hosts for its progenitor. Although RaTG13, sampled from a Rhinolophus affinis bat1, is ~96% identical overall to SARS-CoV-2, its spike diverges in the RBD, which suggests that it may not bind efficiently to human ACE27 (Fig. 1a).

      Malayan pangolins (Manis javanica) illegally imported into Guangdong province contain coronaviruses similar to SARS-CoV-221. Although the RaTG13 bat virus remains the closest to SARS-CoV-2 across the genome1, some pangolin coronaviruses exhibit strong similarity to SARS-CoV-2 in the RBD, including all six key RBD residues21 (Fig. 1). This clearly shows that the SARS-CoV-2 spike protein optimized for binding to human-like ACE2 is the result of natural selection.

      Neither the bat betacoronaviruses nor the pangolin betacoronaviruses sampled thus far have polybasic cleavage sites. Although no animal coronavirus has been identified that is sufficiently similar to have served as the direct progenitor of SARS-CoV-2, the diversity of coronaviruses in bats and other species is massively undersampled. Mutations, insertions and deletions can occur near the S1–S2 junction of coronaviruses22, which shows that the polybasic cleavage site can arise by a natural evolutionary process. For a precursor virus to acquire both the polybasic cleavage site and mutations in the spike protein suitable for binding to human ACE2, an animal host would probably have to have a high population density (to allow natural selection to proceed efficiently) and an ACE2-encoding gene that is similar to the human ortholog.

      Natural selection in an animal host before zoonotic transfer

      As many early cases of COVID-19 were linked to the Huanan market in Wuhan1,2, it is possible that an animal source was present at this location. Given the similarity of SARS-CoV-2 to bat SARS-CoV-like coronaviruses 2, it is likely that bats serve as reservoir hosts for its progenitor. Although RaTG13, sampled from a Rhinolophus affinis bat1, is ~96% identical overall to SARS-CoV-2, its spike diverges in the RBD, which suggests that it may not bind efficiently to human ACE27 (Fig. 1a).

      Malayan pangolins (Manis javanica) illegally imported into Guangdong province contain coronaviruses similar to SARS-CoV-221. Although the RaTG13 bat virus remains the closest to SARS-CoV-2 across the genome 1, some pangolin coronaviruses exhibit strong similarity to SARS-CoV-2 in the RBD, including all six key RBD residues 21 (Fig. 1). This clearly shows that the SARS-CoV-2 spike protein optimized for binding to human-like ACE2 is the result of natural selection.

      Neither the bat betacoronaviruses nor the pangolin betacoronaviruses sampled thus far have polybasic cleavage sites. Although no animal coronavirus has been identified that is sufficiently similar to have served as the direct progenitor of SARS-CoV-2, the diversity of coronaviruses in bats and other species is massively undersampled. Mutations, insertions and deletions can occur near the S1–S2 junction of coronaviruses22, which shows that the polybasic cleavage site can arise by a natural evolutionary process. For a precursor virus to acquire both the polybasic cleavage site and mutations in the spike protein suitable for binding to human ACE2, an animal host would probably have to have a high population density (to allow natural selection to proceed efficiently) and an ACE2-encoding gene that is similar to the human ortholog.

      2. Natural selection in humans following zoonotic transfer

      It is possible that a progenitor of SARS-CoV-2 jumped into humans, acquiring the genomic features described above through adaptation during undetected human-to-human transmission. Once acquired, these adaptations would enable the pandemic to take off and produce a sufficiently large cluster of cases to trigger the surveillance system that detected it1,2.

      All SARS-CoV-2 genomes sequenced so far have the genomic features described above and are thus derived from a common ancestor that had them too. The presence in pangolins of an RBD very similar to that of SARS-CoV-2 means that we can infer this was also probably in the virus that jumped to humans. This leaves the insertion of polybasic cleavage site to occur during human-to-human transmission.

      Estimates of the timing of the most recent common ancestor of SARS-CoV-2 made with current sequence data point to emergence of the virus in late November 2019 to early December 201923, compatible with the earliest retrospectively confirmed cases 24. Hence, this scenario presumes a period of unrecognized transmission in humans between the initial zoonotic event and the acquisition of the polybasic cleavage site. Sufficient opportunity could have arisen if there had been many prior zoonotic events that produced short chains of human-to-human transmission over an extended period. This is essentially the situation for MERS-CoV, for which all human cases are the result of repeated jumps of the virus from dromedary camels, producing single infections or short transmission chains that eventually resolve, with no adaptation to sustained transmission 25.

      © Copyright Original Source



      There is the need for more research on the genetic origins for Covie19 but I believe the evidence points to the wild animals butchered at the Wuhan MArket, and there is along history there, and other places in China.
      Glendower: I can call spirits from the vasty deep.
      Hotspur: Why, so can I, or so can any man;
      But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

      go with the flow the river knows . . .

      Frank

      I do not know, therefore everything is in pencil.

      Comment


      • #33
        To add: The consumption of these animals butchered at Wuhan and consumed in China for medicinal and health reasons is over two thousand years dated to the earliest Chinese writing on health and medicine.
        Glendower: I can call spirits from the vasty deep.
        Hotspur: Why, so can I, or so can any man;
        But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

        go with the flow the river knows . . .

        Frank

        I do not know, therefore everything is in pencil.

        Comment


        • #34
          Originally posted by shunyadragon View Post
          There is the need for more research on the genetic origins for Covie19 but I believe the evidence points to the wild animals butchered at the Wuhan MArket, and there is along history there, and other places in China.
          Your contention was that there's a long history of viruses being transferred to humans there. Still waiting for evidence of that.
          "Any sufficiently advanced stupidity is indistinguishable from trolling."

          Comment


          • #35
            Originally posted by TheLurch View Post
            Your contention was that there's a long history of viruses being transferred to humans there. Still waiting for evidence of that.
            I provided some of it. I did not say it was in any way conclusive, but it is a fact that they are experiencing weaker levels of infections all over the Orient that I believe may be partly explained be herd immunity, which has been the case for many pandemics throughout the history of humanity. Your bogus response coronaviruses are everywhere was meaningless.
            Last edited by shunyadragon; 04-10-2020, 08:08 AM.
            Glendower: I can call spirits from the vasty deep.
            Hotspur: Why, so can I, or so can any man;
            But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

            go with the flow the river knows . . .

            Frank

            I do not know, therefore everything is in pencil.

            Comment


            • #36
              Originally posted by shunyadragon View Post
              I provided some of it. I did not say it was in any way conclusive, but it is a fact that they are experiencing weaker levels of infections all over the Orient that I believe may be partly explained be herd immunity, which has been the case for many pandemics throughout the history of humanity. Your bogus response coronaviruses are everywhere was meaningless.
              It's not a bogus response. You have to explain why the strains of coronavirus found in East Asia are in some way different from the ones that are endogenous to the rest of the planet. Otherwise, we'd all have herd immunity.

              Note: as far as i'm aware, the genome sequences indicate they're not that different, so you have a large hurdle to clear here.
              "Any sufficiently advanced stupidity is indistinguishable from trolling."

              Comment


              • #37
                Originally posted by TheLurch View Post
                They are not the curves you get from an infection with no preventive measures being taken. If you want to define that as "natural", go ahead, but it's not how most people use the term.
                The curves people like to stare at now are not informative, because part of the increase is obviously due to an increase in testing. How much of the observed increase is due to actual cases increase and how much to testing increases is generally not deconvoluted. Just using the raw curve to predict a peak is basically useless.
                Remember that you are dust and to dust you shall return.

                Comment


                • #38
                  Originally posted by TheLurch View Post
                  It's not a bogus response. You have to explain why the strains of coronavirus found in East Asia are in some way different from the ones that are endogenous to the rest of the planet. Otherwise, we'd all have herd immunity.

                  Note: as far as i'm aware, the genome sequences indicate they're not that different, so you have a large hurdle to clear here.
                  Hey, Lurch. I don't have your expertise, but I'm trying to keep my students and folks I encounter online abreast of the best information available. I'd consider it a real favor if you were to check my math on the Imperial College COVID-19 Response Team Report / March 16. I presented those results to my students. I need to fix that if I got it wrong.

                  In another thread, I'm trying to extend those results to a new report suggesting R0 is not on the order of 2.2 to 2.6, but is instead around 5.7. The report itself looks kinda shaky to me, and if you could look at that, too ...

                  I know, everyone is overburdened right now, but if you could give me a bit of your time, I'll multiply it with my students.

                  Comment


                  • #39
                    Originally posted by Juvenal View Post
                    Hey, Lurch. I don't have your expertise, but I'm trying to keep my students and folks I encounter online abreast of the best information available. I'd consider it a real favor if you were to check my math on the Imperial College COVID-19 Response Team Report / March 16. I presented those results to my students. I need to fix that if I got it wrong.

                    In another thread, I'm trying to extend those results to a new report suggesting R0 is not on the order of 2.2 to 2.6, but is instead around 5.7. The report itself looks kinda shaky to me, and if you could look at that, too ...

                    I know, everyone is overburdened right now, but if you could give me a bit of your time, I'll multiply it with my students.
                    Completely blanked on that, sorry - will set it aside to look this evening.

                    EDIT: one of your links is broken.
                    Last edited by TheLurch; 04-10-2020, 10:47 AM.
                    "Any sufficiently advanced stupidity is indistinguishable from trolling."

                    Comment


                    • #40
                      Originally posted by TheLurch View Post
                      Completely blanked on that, sorry - will set it aside to look this evening.

                      EDIT: one of your links is broken.
                      And of course it's the more important link.



                      But it's also the same link I shared earlier.

                      Comment


                      • #41
                        Originally posted by TheLurch View Post
                        It's not a bogus response. You have to explain why the strains of coronavirus found in East Asia are in some way different from the ones that are endogenous to the rest of the planet. Otherwise, we'd all have herd immunity.

                        Note: as far as i'm aware, the genome sequences indicate they're not that different, so you have a large hurdle to clear here.
                        You have failed to acknowledge that the whole history of the relationship between humans and viruses is regional differences and herd immunity in thse regions and contacts between regions in the past have resulted in pandemics in regions that lack the herd immunity.

                        You cannot compare regional viruses like MERS with the regional viruses from China.
                        Last edited by shunyadragon; 04-10-2020, 11:40 AM.
                        Glendower: I can call spirits from the vasty deep.
                        Hotspur: Why, so can I, or so can any man;
                        But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                        go with the flow the river knows . . .

                        Frank

                        I do not know, therefore everything is in pencil.

                        Comment


                        • #42
                          Originally posted by shunyadragon View Post
                          You cannot compare regional viruses like MERS with the regional viruses from China.
                          Why not?
                          "Any sufficiently advanced stupidity is indistinguishable from trolling."

                          Comment


                          • #43
                            Originally posted by TheLurch View Post
                            Why not?
                            . . . because as I have described that even though all viruses are, of course, related as viruses through billions of years of evolution there are regionally distinct viruses that evolve with their animal hosts including humans. The evidence of this regional relationship is that both humans and the viruses evolve in this relationship. There are many cases in the past that in the past humans in one region developed 'herd immunity' from their viruses, and when exposed to regions without the 'herd immunity' creating more severe pandemics. There is nothing wrong with considering the possibility that in the Orient especially among the Chinese, since it was common throughout the history of China that they consumed those animals for medicinal and health purposes, and likewise in Korea and Japan, which inherited Chinese traditional medicine from the Tang Dynasty to the present. I know some of this history in Chinese when I investigated this when I lived in China during the SARS epidemic. I believe a more recent New York Times article addressed this recently, and I will try and find it.

                            No, you cannot compare MERS, with SARS, and the Coval-19, because they are evolved viruses in their own environments and different host relationships.
                            Last edited by shunyadragon; 04-10-2020, 06:36 PM.
                            Glendower: I can call spirits from the vasty deep.
                            Hotspur: Why, so can I, or so can any man;
                            But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                            go with the flow the river knows . . .

                            Frank

                            I do not know, therefore everything is in pencil.

                            Comment


                            • #44
                              Originally posted by shunyadragon View Post
                              No, you cannot compare MERS, with SARS, and the Coval-19, because they are evolved viruses in their own environments and different host relationships.
                              They are all coronaviruses from the same genera that evolved in an animal host before acquiring mutations that allowed them to infect humans. In humans, they infect a similar range of cells and cause a similar range of symptoms. There are some differences among them, but they are very comparable.
                              "Any sufficiently advanced stupidity is indistinguishable from trolling."

                              Comment


                              • #45
                                Originally posted by TheLurch View Post
                                They are all coronaviruses from the same genera that evolved in an animal host before acquiring mutations that allowed them to infect humans. In humans, they infect a similar range of cells and cause a similar range of symptoms. There are some differences among them, but they are very comparable.
                                The evidence is conclusive that colds, flus, MERS, SARS, numerous other viruses, and COVAG 19 are of course, all viruses, but that is where similarity ends. China coronaviruses related to SARS and the Wuhan coronavirus are part of a distinctive family of viruses.

                                Source: https://www.businessinsider.com/wuhan-coronavirus-genome-close-to-sars-originated-in-bats-2020-2



                                In the first study, a team led by scientists at the Wuhan Institute of Virology looked at virus samples from seven patients that initially reported cases of severe pneumonia. Six of the patients worked at the Huanan wholesale seafood market in Wuhan, China, which is thought to be where the outbreak started in December. About 70% of the samples were nearly identical to each other, and their genetic sequence was 79.5% similar to SARS.

                                The researchers behind that study also found that 2019-nCoV is nearly identical to other coronaviruses circulating in Chinese bat populations — 96% of the genetic codes match.

                                A second study, led by scientists from Fudan University in Shanghai and the Chinese Center for Disease Control and Prevention, examined a 41-year-old male who also worked at the market. He checked into a Wuhan hospital on December 26 with symptoms of respiratory illness and a fever. An analysis of the virus that infected him showed it is 89% similar to a group of SARS-like coronaviruses called betacoronaviruses that had previously been found in Chinese bats.

                                © Copyright Original Source

                                Glendower: I can call spirits from the vasty deep.
                                Hotspur: Why, so can I, or so can any man;
                                But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

                                go with the flow the river knows . . .

                                Frank

                                I do not know, therefore everything is in pencil.

                                Comment

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