8 ms·

Is there any evidence that this new 'variant' has any impact to infectiousness or death? Or is it simply genetic drift?

by iridium_core 6y ago

avl999 6y ago
No evidence that it is deadlier than other variants. Some evidence that it is more infectious.
- sbinthree 6y ago
  It's been rapidly becoming the dominant variant in places with various different kinds of measures so I think it's for sure more infectious at this point.
  - iridium_core 6y ago
    So incessant, and seemingly ineffective, lockdowns have succeeded - in selecting for a variant of COVID which is resistant to lockdown? What biological or physical mechanism could allow it to spread more than the original?
    - sbinthree 6y ago
      Yes
    - wwweston 6y ago
      On one hand, it may be plausible that taking any measure that makes it harder to spread... favors a variant that can spread more easily. On the other hand, spreading more easily means higher reproductive fitness under any circumstance. And not taking measures to reduce spread probably just means more infections faster, which is more opportunity for reproduction and mutation, which means you probably get higher fitness variations sooner. Also I'm trying to think of anywhere in US/UK society for which "incessant lockdown" could possibly be an accurate description of policy much less behavior.
    - nmca 6y ago
      Imperial study was in the context of a tiered UK system that keeps schools, so increased infection from young people is my personal and ill-informed hypothesis of how the new variant achieved 50-70% increased r0 under restrictions.
- JamesBarney 6y ago
  Just a reminder that greater infectiousness is worse than greater lethality. Say you have two variants, variant S-spreader and variant L-lethal. S kills 1 in 100 people and has a doubling time of 3.5 days L kills 2 in 100 people and has a doubling time of a week. First week L kills twice as many people of S. Week 2 they kill the same number of people. Week 3 S kills twice as many people as L Week 4 S kills 4x as many people as L.
  - lazyjones 6y ago
    This is plain wrong. You have 2 variables there and can't claim that one has greater effect based on 2 examples. It can be refuted by a suitably chosen 3rd example, e.g. N-nonlethal kills 1 in 10000000000000 people and has a doubling time of 1 day.
- fpgaminer 6y ago
  It should be noted that increased infectiousness will inherently result in a larger number of deaths, even if it is not "deadlier". i.e. the new strain may still only be fatal in 0.5% of cases, but if it infects more people that's more rolls of the dice. The original strain was only projected to infect 60-70% of the population (if left unchecked). A new strain being 70% more infectious drastically changes that figure. Not to mention a similar uptick in serious cases and even just more people presenting to the hospital. Imagine the current situation, where some cities are already at 0% capacity, but 70% worse... Just something worth noting when we say that a new strain is _just_ more infectious.
  - Erlich_Bachman 6y ago
    Yep, but at the same time if they would have said that it is "more infectious and more deadly" - that would have even more incorrect (without clarification), given that those terms usually refer to specific properties.
  - lazyjones 6y ago
    > It should be noted that increased infectiousness will inherently result in a larger number of deaths, even if it is not "deadlier". That's wrong if this virus, like many other viruses, is mutating to become simultaneously more infectious and less lethal. https://www.reuters.com/article/us-health-coronavirus-mutation-idUSKCN25E08Y https://www.reuters.com/article/us-health-coronavirus-mutati...
    - graeme 6y ago
      Actually it isn’t wrong. A 70% increase in an exponential gain leads to many multiples more cases. You could halve the death rate in that scenario and still have 10x the number of deaths or more. Run two exponential series: one at 1.1x, one at 1.7x. Start at 1,000 cases each. Death rate 1% for the first, 0.5% for the second. Assume doubling in a week. Check new cases and thus new deaths after eight weeks. 2143 new cases on week eight fir the second one, 21.4 deaths. 110,199 new cases on week eight for second one, resulting in 550.5 deaths. 20x worse. And unfortunately the new strain doesn’t seem to be less deadly, so it would be 40x worse if death rate the same.
maxerickson 6y ago
What does 'evidence' mean in the question? There is certainly something going on in the UK and Ireland, but it's not a randomized controlled study designed to measure the infectiousness of the variants that have recently been sampled there. (because it's exponential, higher infectiousness can be quite a lot worse than higher lethality)
aqme28 6y ago
The British variant is estimated to be about 40-70% more infectious, which is pretty bad of course. https://www.who.int/csr/don/21-december-2020-sars-cov2-variant-united-kingdom/en/ https://www.who.int/csr/don/21-december-2020-sars-cov2-varia...
JamesBarney 6y ago
There is. In the UK you are seeing a huge spike in infections at the same time the percentage of coronaviruses attributed to the new variant sky rocket. Look here for how one of the lines is not like the others. (UK) https://ourworldindata.org/coronavirus-data-explorer?zoomToSelection=true&time=2020-03-01..latest&country=IND~USA~GBR~CAN~DEU~FRA&region=World&casesMetric=true&interval=smoothed&perCapita=true&smoothing=7&pickerMetric=total_cases&pickerSort=desc https://ourworldindata.org/coronavirus-data-explorer?zoomToS...
elij 6y ago
https://www.imperial.ac.uk/mrc-global-infectious-disease-analysis/covid-19/report-42-sars-cov-2-variant/ https://www.imperial.ac.uk/mrc-global-infectious-disease-ana... It's very important, specifically in the UK, to put N501Y in the context of political decisions that impact the R index. https://twitter.com/dgurdasani1/status/1344774576371335175 https://twitter.com/dgurdasani1/status/1344774576371335175
graeme 6y ago
Yes. Denmark has studied it and the new variant is doubling its prevalence in denmark every week too.

Is there any evidence that this new 'variant' has any impact to infectiousness or death? Or is it simply genetic drift?

avl999 6y ago

No evidence that it is deadlier than other variants. Some evidence that it is more infectious.

sbinthree 6y ago
It's been rapidly becoming the dominant variant in places with various different kinds of measures so I think it's for sure more infectious at this point.
- iridium_core 6y ago
  So incessant, and seemingly ineffective, lockdowns have succeeded - in selecting for a variant of COVID which is resistant to lockdown? What biological or physical mechanism could allow it to spread more than the original?
  - sbinthree 6y ago
    Yes
  - wwweston 6y ago
    On one hand, it may be plausible that taking any measure that makes it harder to spread... favors a variant that can spread more easily. On the other hand, spreading more easily means higher reproductive fitness under any circumstance. And not taking measures to reduce spread probably just means more infections faster, which is more opportunity for reproduction and mutation, which means you probably get higher fitness variations sooner. Also I'm trying to think of anywhere in US/UK society for which "incessant lockdown" could possibly be an accurate description of policy much less behavior.
  - nmca 6y ago
    Imperial study was in the context of a tiered UK system that keeps schools, so increased infection from young people is my personal and ill-informed hypothesis of how the new variant achieved 50-70% increased r0 under restrictions.
JamesBarney 6y ago
Just a reminder that greater infectiousness is worse than greater lethality. Say you have two variants, variant S-spreader and variant L-lethal. S kills 1 in 100 people and has a doubling time of 3.5 days L kills 2 in 100 people and has a doubling time of a week. First week L kills twice as many people of S. Week 2 they kill the same number of people. Week 3 S kills twice as many people as L Week 4 S kills 4x as many people as L.
- lazyjones 6y ago
  This is plain wrong. You have 2 variables there and can't claim that one has greater effect based on 2 examples. It can be refuted by a suitably chosen 3rd example, e.g. N-nonlethal kills 1 in 10000000000000 people and has a doubling time of 1 day.
fpgaminer 6y ago
It should be noted that increased infectiousness will inherently result in a larger number of deaths, even if it is not "deadlier". i.e. the new strain may still only be fatal in 0.5% of cases, but if it infects more people that's more rolls of the dice. The original strain was only projected to infect 60-70% of the population (if left unchecked). A new strain being 70% more infectious drastically changes that figure. Not to mention a similar uptick in serious cases and even just more people presenting to the hospital. Imagine the current situation, where some cities are already at 0% capacity, but 70% worse... Just something worth noting when we say that a new strain is _just_ more infectious.
- Erlich_Bachman 6y ago
  Yep, but at the same time if they would have said that it is "more infectious and more deadly" - that would have even more incorrect (without clarification), given that those terms usually refer to specific properties.
- lazyjones 6y ago
  > It should be noted that increased infectiousness will inherently result in a larger number of deaths, even if it is not "deadlier". That's wrong if this virus, like many other viruses, is mutating to become simultaneously more infectious and less lethal. https://www.reuters.com/article/us-health-coronavirus-mutation-idUSKCN25E08Y https://www.reuters.com/article/us-health-coronavirus-mutati...
  - graeme 6y ago
    Actually it isn’t wrong. A 70% increase in an exponential gain leads to many multiples more cases. You could halve the death rate in that scenario and still have 10x the number of deaths or more. Run two exponential series: one at 1.1x, one at 1.7x. Start at 1,000 cases each. Death rate 1% for the first, 0.5% for the second. Assume doubling in a week. Check new cases and thus new deaths after eight weeks. 2143 new cases on week eight fir the second one, 21.4 deaths. 110,199 new cases on week eight for second one, resulting in 550.5 deaths. 20x worse. And unfortunately the new strain doesn’t seem to be less deadly, so it would be 40x worse if death rate the same.

maxerickson 6y ago

What does 'evidence' mean in the question? There is certainly something going on in the UK and Ireland, but it's not a randomized controlled study designed to measure the infectiousness of the variants that have recently been sampled there. (because it's exponential, higher infectiousness can be quite a lot worse than higher lethality)

aqme28 6y ago

The British variant is estimated to be about 40-70% more infectious, which is pretty bad of course. https://www.who.int/csr/don/21-december-2020-sars-cov2-variant-united-kingdom/en/ https://www.who.int/csr/don/21-december-2020-sars-cov2-varia...

JamesBarney 6y ago

There is. In the UK you are seeing a huge spike in infections at the same time the percentage of coronaviruses attributed to the new variant sky rocket. Look here for how one of the lines is not like the others. (UK) https://ourworldindata.org/coronavirus-data-explorer?zoomToSelection=true&time=2020-03-01..latest&country=IND~USA~GBR~CAN~DEU~FRA&region=World&casesMetric=true&interval=smoothed&perCapita=true&smoothing=7&pickerMetric=total_cases&pickerSort=desc https://ourworldindata.org/coronavirus-data-explorer?zoomToS...

elij 6y ago

https://www.imperial.ac.uk/mrc-global-infectious-disease-analysis/covid-19/report-42-sars-cov-2-variant/ https://www.imperial.ac.uk/mrc-global-infectious-disease-ana... It's very important, specifically in the UK, to put N501Y in the context of political decisions that impact the R index. https://twitter.com/dgurdasani1/status/1344774576371335175 https://twitter.com/dgurdasani1/status/1344774576371335175

graeme 6y ago

Yes. Denmark has studied it and the new variant is doubling its prevalence in denmark every week too.