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> presuming worldwide that we all maintained strict lockdown until the vaccine was universally available and the vast majority of the population took it We all

> presuming worldwide that we all maintained strict lockdown until the vaccine was universally available and the vast majority of the population took it We all remember that the vaccines were described as being able to prevent infection and transmission, certainly by some politicians, perhaps less so by scientists. One of those very politicians is currently Covid positive after four (count them) shots of vaccine. Doesn't mass vaccination, particularly with imperfect vaccines, increase the selection pressure on the virus to mutate? With hindsight I wish there had been much more international focus on protecting and vaccinating those truly at risk. It seems fairly clear by now that fit and healthy under-50s really didn't gain much from vaccination, their risk from this particularly virus was already tiny. After a couple of months the vaccines didn't stop them catching and spreading the virus either, so they weren't even protecting the vulnerable indirectly.

pertymcpert 4y ago
I don't think that's true. Vaccination is still beneficial to infection. Selection pressure exists, but they will exist whether or not the immune pressure comes from vaccination or infection, so it's preferable to protect first.
- logifail 4y ago
  > I don't think that's true. Vaccination is still beneficial to infection. The virus changed, thanks to Omicron not even the WHO agrees with that claim. "Vaccine-induced immunity following a primary vaccine series is modest against infection due to Omicron in the months after vaccination, and wanes significantly over time. Vaccine-induced immunity against Omicron-related mild symptomatic disease, asymptomatic infection, and viral shedding is also modest and short-lived even following a booster dose." https://www.who.int/news/item/01-06-2022-interim-statement-on-hybrid-immunity-and-increasing-population-seroprevalence-rates https://www.who.int/news/item/01-06-2022-interim-statement-o...
  - kenjackson 4y ago
    But from the same report: “ Currently available data from emergency-use listed COVID-19 vaccines show that vaccines provide higher levels of protection than SARS-CoV-2 infection against severe disease outcomes, with modest waning in the 6 months following completion of primary vaccine series. Further, they continue to protect against severe disease, hospitalizations and death due to Omicron, albeit to a lesser degree compared with other VOC.”
    - logifail 4y ago
      > But from the same report: “ Currently available data from emergency-use listed COVID-19 vaccines show that vaccines provide higher levels of protection than SARS-CoV-2 infection against severe disease outcomes [Now that we have them] the vaccines are indeed effective at protecting against severe outcomes. Even before the vaccines, and against this particular virus, being young and healthy is and always was also exceptionally effective: "People of different ages have been exposed to dramatically differing risks. Fatalities among school-children have been remarkably low. Taking women aged 30–34 as an example, around 1 in 70,000 died from Covid over the 9 peak weeks of the epidemic. Since over 80% of these had pre-existing medical conditions, we estimate that a healthy women in this age-group had less than a 1 in 350,000 risk of dying from Covid, around 1/4 of the normal risk of an accidental death over this period"[0] (from May 2020): "Coronavirus risk for young is 'staggeringly low', says UK's top statistician [..] “If we look at under 25s, there're 17 million of them in the country where we have 26 deaths recorded,” he said, suggesting a similar risk would be seen in “a couple of days” in general accidents and sudden deaths. However, he said the risk for the over 90s was 10,000 times as high, with more than one per cent of over 90s having died from Covid-19."[1] [0] https://medium.com/wintoncentre/what-have-been-the-fatal-risks-of-covid-particularly-to-children-and-younger-adults-a5cbf7060c49 https://medium.com/wintoncentre/what-have-been-the-fatal-ris... [1] https://archive.ph/WYas8 https://archive.ph/WYas8 ( https://www.telegraph.co.uk/news/2020/05/10/coronavirus-risk-young-staggeringly-low-says-uks-top-statistician/ https://www.telegraph.co.uk/news/2020/05/10/coronavirus-risk... )
Izkata 4y ago
> Doesn't mass vaccination, particularly with imperfect vaccines, increase the selection pressure on the virus to mutate? Absolutely: The variant that later became known as Delta was first identified in Oct 2020. The vaccines didn't start their heavy rollout until the beginning of 2021, and it took months before a decent percent of the population had been vaccinated. Before that point there was little concern about variants, as the virus didn't seem to be mutating very much in ways that would heavily change its infectivity dynamics. But after that? That's when Delta started easily out-competing prior variants, with the "delta waves" occurring in mid/late 2021. And since then we keep getting more and more named "variants of concern" that are expected to escape immunity.
- bonzini 4y ago
  This is incorrect. First, Alpha was from Dec 2020-Jan 2021 in the UK and was already substantially more infectious than the Wuhan wild type or D614G variant, though it did not escape immunity. Second, as far as we know neither Delta nor Omicron (nor all the other Greek letters that were outcompeted by them) developed in vaccinated people, and both of them are anyway incredibly more infectious even in unvaccinated people. I don't know about BA.4/5 but, at least for the three main lineages of concern that drove waves after mass vaccination, selective pressure was not a cause of either the birth or the spreading of the variant.
  - logifail 4y ago
    Where did Omicron come from? Three key theories https://www.nature.com/articles/d41586-022-00215-2 https://www.nature.com/articles/d41586-022-00215-2 "Omicron forms a stronger grip on ACE2 than do previously seen variants3. It is also better at evading the virus-blocking ‘neutralizing’ antibodies4 produced by people who have been vaccinated, or who have been infected with earlier variants [..] At some point [..] something happened to help Omicron explode, maybe because the progress of other variants — such as Delta — was gradually impeded by the immunity built up from vaccination and previous infection, whereas Omicron was able to evade this barrier."
    - 4y ago

pertymcpert 4y ago

I don't think that's true. Vaccination is still beneficial to infection. Selection pressure exists, but they will exist whether or not the immune pressure comes from vaccination or infection, so it's preferable to protect first.

logifail 4y ago
> I don't think that's true. Vaccination is still beneficial to infection. The virus changed, thanks to Omicron not even the WHO agrees with that claim. "Vaccine-induced immunity following a primary vaccine series is modest against infection due to Omicron in the months after vaccination, and wanes significantly over time. Vaccine-induced immunity against Omicron-related mild symptomatic disease, asymptomatic infection, and viral shedding is also modest and short-lived even following a booster dose." https://www.who.int/news/item/01-06-2022-interim-statement-on-hybrid-immunity-and-increasing-population-seroprevalence-rates https://www.who.int/news/item/01-06-2022-interim-statement-o...
- kenjackson 4y ago
  But from the same report: “ Currently available data from emergency-use listed COVID-19 vaccines show that vaccines provide higher levels of protection than SARS-CoV-2 infection against severe disease outcomes, with modest waning in the 6 months following completion of primary vaccine series. Further, they continue to protect against severe disease, hospitalizations and death due to Omicron, albeit to a lesser degree compared with other VOC.”
  - logifail 4y ago
    > But from the same report: “ Currently available data from emergency-use listed COVID-19 vaccines show that vaccines provide higher levels of protection than SARS-CoV-2 infection against severe disease outcomes [Now that we have them] the vaccines are indeed effective at protecting against severe outcomes. Even before the vaccines, and against this particular virus, being young and healthy is and always was also exceptionally effective: "People of different ages have been exposed to dramatically differing risks. Fatalities among school-children have been remarkably low. Taking women aged 30–34 as an example, around 1 in 70,000 died from Covid over the 9 peak weeks of the epidemic. Since over 80% of these had pre-existing medical conditions, we estimate that a healthy women in this age-group had less than a 1 in 350,000 risk of dying from Covid, around 1/4 of the normal risk of an accidental death over this period"[0] (from May 2020): "Coronavirus risk for young is 'staggeringly low', says UK's top statistician [..] “If we look at under 25s, there're 17 million of them in the country where we have 26 deaths recorded,” he said, suggesting a similar risk would be seen in “a couple of days” in general accidents and sudden deaths. However, he said the risk for the over 90s was 10,000 times as high, with more than one per cent of over 90s having died from Covid-19."[1] [0] https://medium.com/wintoncentre/what-have-been-the-fatal-risks-of-covid-particularly-to-children-and-younger-adults-a5cbf7060c49 https://medium.com/wintoncentre/what-have-been-the-fatal-ris... [1] https://archive.ph/WYas8 https://archive.ph/WYas8 ( https://www.telegraph.co.uk/news/2020/05/10/coronavirus-risk-young-staggeringly-low-says-uks-top-statistician/ https://www.telegraph.co.uk/news/2020/05/10/coronavirus-risk... )

Izkata 4y ago

> Doesn't mass vaccination, particularly with imperfect vaccines, increase the selection pressure on the virus to mutate? Absolutely: The variant that later became known as Delta was first identified in Oct 2020. The vaccines didn't start their heavy rollout until the beginning of 2021, and it took months before a decent percent of the population had been vaccinated. Before that point there was little concern about variants, as the virus didn't seem to be mutating very much in ways that would heavily change its infectivity dynamics. But after that? That's when Delta started easily out-competing prior variants, with the "delta waves" occurring in mid/late 2021. And since then we keep getting more and more named "variants of concern" that are expected to escape immunity.

bonzini 4y ago
This is incorrect. First, Alpha was from Dec 2020-Jan 2021 in the UK and was already substantially more infectious than the Wuhan wild type or D614G variant, though it did not escape immunity. Second, as far as we know neither Delta nor Omicron (nor all the other Greek letters that were outcompeted by them) developed in vaccinated people, and both of them are anyway incredibly more infectious even in unvaccinated people. I don't know about BA.4/5 but, at least for the three main lineages of concern that drove waves after mass vaccination, selective pressure was not a cause of either the birth or the spreading of the variant.
- logifail 4y ago
  Where did Omicron come from? Three key theories https://www.nature.com/articles/d41586-022-00215-2 https://www.nature.com/articles/d41586-022-00215-2 "Omicron forms a stronger grip on ACE2 than do previously seen variants3. It is also better at evading the virus-blocking ‘neutralizing’ antibodies4 produced by people who have been vaccinated, or who have been infected with earlier variants [..] At some point [..] something happened to help Omicron explode, maybe because the progress of other variants — such as Delta — was gradually impeded by the immunity built up from vaccination and previous infection, whereas Omicron was able to evade this barrier."
  - 4y ago