3 ms·

What does 70% more transmissible mean?

kordlessagain 6y ago
R number changed when that one nucleotide change increased the number of spikes on the surface by 5-8X. This modification was seen occurring in multiple locations, so maybe not a single linage change. Maybe more like an increase in probability that one nucleotide would "flip" in multiple organisms, with enough organisms at hand. The spike itself attacks/props open ACE2 receptors, like those found on your eyes, and is mostly encoded using ~39 some odd nucleotides borrowed from a South Asian fish. Plotting the number of "words" repeated in the genome (~30K nucleotides) yields a phi-like curve, with the words/codons in the spike occurring more statistically significantly than others. The mutation is not expected to cause more severe cases, but is more infectious due to more spikes needing to be neutralized to fend off the infection. In bloodstream plant lectins have been shown to be effective at this, as well as llama nanoparticles. All of this is Googlable using the right key terms. Fish DNA in the spike: https://dnascience.plos.org/2020/02/20/covid-19-vaccine-will-close-in-on-the-spikes/ https://dnascience.plos.org/2020/02/20/covid-19-vaccine-will... One nucleotide changes number of spikes: https://www.washingtonpost.com/science/2020/06/29/coronavirus-mutation-science/?arc404=true https://www.washingtonpost.com/science/2020/06/29/coronaviru...
- mehrdadn 6y ago
  Oh thanks, I was just trying to understand what it's measuring. So are they saying its R factor is now 1.7R?
  - kordlessagain 6y ago
    Not sure on the new R number. Not a lot of data yet. Check this out, however: https://www.sciencedaily.com/releases/2020/11/201112144040.htm https://www.sciencedaily.com/releases/2020/11/201112144040.h... > Kawaoka and Halfmann contributed their unique coronavirus study model, which uses hamsters. The University of Wisconsin-Madison team -- including Shiho Chiba, who ran the hamster experiments -- performed replication and airborne transmission studies with both the original virus and the mutated version created by Baric and Hou. > They found that the mutated virus not only replicates about 10 times faster -- it's also much more infectious. > Hamsters were inoculated with one virus or the other. The next day, eight uninfected hamsters were placed into cages next to infected hamsters. There was a divider between them so they could not touch, but air could pass between the cages. > Researchers began looking for replication of the virus in the uninfected animals on day two. Both viruses passed between animals via airborne transmission, but the timing was different. > With the mutant virus, the researchers saw transmission to six out of eight hamsters within two days, and to all the hamsters by day four. With the original virus, they saw no transmission on day two, though all of the exposed animals were infected by day four. > "We saw that the mutant virus transmits better airborne than the [original] virus, which may explain why this virus dominated in humans," Kawaoka said.
    - mehrdadn 6y ago
      Thanks but I'm still confused what 70% is referring to. Exactly what quantity is 70% higher than it used to be?

R number changed when that one nucleotide change increased the number of spikes on the surface by 5-8X. This modification was seen occurring in multiple locations, so maybe not a single linage change. Maybe more like an increase in probability that one nucleotide would "flip" in multiple organisms, with enough organisms at hand. The spike itself attacks/props open ACE2 receptors, like those found on your eyes, and is mostly encoded using ~39 some odd nucleotides borrowed from a South Asian fish. Plotting the number of "words" repeated in the genome (~30K nucleotides) yields a phi-like curve, with the words/codons in the spike occurring more statistically significantly than others. The mutation is not expected to cause more severe cases, but is more infectious due to more spikes needing to be neutralized to fend off the infection. In bloodstream plant lectins have been shown to be effective at this, as well as llama nanoparticles. All of this is Googlable using the right key terms. Fish DNA in the spike: https://dnascience.plos.org/2020/02/20/covid-19-vaccine-will-close-in-on-the-spikes/ https://dnascience.plos.org/2020/02/20/covid-19-vaccine-will... One nucleotide changes number of spikes: https://www.washingtonpost.com/science/2020/06/29/coronavirus-mutation-science/?arc404=true https://www.washingtonpost.com/science/2020/06/29/coronaviru...

mehrdadn 6y ago
Oh thanks, I was just trying to understand what it's measuring. So are they saying its R factor is now 1.7R?
- kordlessagain 6y ago
  Not sure on the new R number. Not a lot of data yet. Check this out, however: https://www.sciencedaily.com/releases/2020/11/201112144040.htm https://www.sciencedaily.com/releases/2020/11/201112144040.h... > Kawaoka and Halfmann contributed their unique coronavirus study model, which uses hamsters. The University of Wisconsin-Madison team -- including Shiho Chiba, who ran the hamster experiments -- performed replication and airborne transmission studies with both the original virus and the mutated version created by Baric and Hou. > They found that the mutated virus not only replicates about 10 times faster -- it's also much more infectious. > Hamsters were inoculated with one virus or the other. The next day, eight uninfected hamsters were placed into cages next to infected hamsters. There was a divider between them so they could not touch, but air could pass between the cages. > Researchers began looking for replication of the virus in the uninfected animals on day two. Both viruses passed between animals via airborne transmission, but the timing was different. > With the mutant virus, the researchers saw transmission to six out of eight hamsters within two days, and to all the hamsters by day four. With the original virus, they saw no transmission on day two, though all of the exposed animals were infected by day four. > "We saw that the mutant virus transmits better airborne than the [original] virus, which may explain why this virus dominated in humans," Kawaoka said.
  - mehrdadn 6y ago
    Thanks but I'm still confused what 70% is referring to. Exactly what quantity is 70% higher than it used to be?