16 ms·

Interesting shift in strategy. Instead of giving the second dose within a few weeks of the first they’re going to allow up to 12 weeks between doses. Allows the

by kjakm 6y ago

Interesting shift in strategy. Instead of giving the second dose within a few weeks of the first they’re going to allow up to 12 weeks between doses. Allows them to get more widespread level of some protection with dose 1 before later boosting protection.

interdrift 6y ago
Good idea indeed!
neals 6y ago
What would be interesting about that is what happens when people are not going to get the booster for various reasons.
- jimmygrapes 6y ago
  Mutation?
  - f6v 6y ago
    Mutations happen all the time regardless of vaccines. The vaccine adds evolutionary pressure and will likely give an advantage to the bearers of particular mutations.
    - ptaipale 6y ago
      If the virus has a smaller base of infected people who grow it, there will be less mutations. From that point of view, the sooner all the world is vaccinated, the better. The risk of a new, more dangerous mutation decreases.
- ehsankia 6y ago
  I think early data showed that you still get ~60% protection with the first shot (or was that for the Moderna vaccine?) Still, you get some level of immunity, booster only makes it higher.
  - maxerickson 6y ago
    The two dose studies provide incomplete information about the single dose efficacy — administration of the second dose ends the data collection for the first dose alone. The data collection also includes the period of time that the body spends responding to the vaccine (so if you get the shot and get infected that day, the shot gets counted as not being effective). And then on the other side of it, they don't have data on how long immunity from a single dose would last. But it's likely that the Moderna and Pfizer vaccines have quite high effectiveness after the initial immune response.
    - ehsankia 6y ago
      Sure, while it's not perfect, the data for those 3 weeks between the first and second shot still can provide a lower bound approximation for immunity, which I assume is where the 60% comes from. The point about how long single dose immunity lasts is fair though.
- sgt101 6y ago
  Why would they not get the booster?
  - jackweirdy 6y ago
    Some will forget, some won’t realise they need it, some will get symptoms the first time and not want it. I don’t expect it will be widespread but humans will be human
  - whiddershins 6y ago
    Why do people miss their flight? So much so that airlines can oversell a substantial number of tickets on any given flight and usually the plane departs with empty seats? Why do people get divorced? Why do...
  - neals 6y ago
    You must not be a software developer
- BurningFrog 6y ago
  All that happens is that they have somewhat smaller protection for a shorter time. Unless the vaccine or virus is very different from normal ones.
theflowerpot 6y ago
Recent reports mention 95% effectiveness for the Oxford-AstraZeneca vaccine if the doses are taken 3 months apart, which would be great if confirmed. https://www.businesstoday.in/current/economy-politics/oxford-covid19-vaccine-95-per-cent-effective-if-given-3-months-apart-says-siis-adar-poonawalla/story/426336.html https://www.businesstoday.in/current/economy-politics/oxford... https://www.thetimes.co.uk/article/covid-vaccine-boost-for-millions-as-hospitals-near-breaking-point-vj7fpj2hr https://www.thetimes.co.uk/article/covid-vaccine-boost-for-m...
- BillyTheKing 6y ago
  they always seem to find additional data supporting this or that. Idk, to me it seems like their reporting is literally all over the place, how did they confirm 95% effectiveness? what's the trial-size, is it also 30k participants like the others? What's the age-distribution of those that took part in this 3-months trial, there are a ton of unknowns with that vaccine, and neither Oxford nor AZ are particularly helpful with clearing those doubts atm.
  - grey-area 6y ago
    They have in many ways been more rigorous and transparent than other vaccine trials (weekly swab testing of all subjects, publishing the paper first rather than in the media first, being honest about mistakes made). They don’t control the media reporting. That said it seems the group who received smaller doses by mistake was only 1300, not sure where they got the data on 12 weeks but presumably it’s also a small number or they’d be going with that for everyone. Things should become clearer over time and I hope they can shift to the smaller doses first as it’d give us double the number of initial vaccinations when supplies are limited.
    - BillyTheKing 6y ago
      the just tried to fit in numerous trials into a single trial, whereas Biontech/Pfizer and Moderna were super clear about their trial-architecture and data (same 2-dose regime, given 3 weeks apart), we seem to have a ton of small trials with different data for that Oxford/AZ vaccine. Those 1300 participants who got the half dose full dose vaccine also turned out to be significantly younger than the other group who got the two full-dose regime, making those two groups really difficult to compare (apart from the fact that they were also differing in size) Now we have a new number out there, 90% if the two doses are given 3 months apart, does anyone here now what the trial-size was? the age distribution? The statistical significance for that finding?
f6v 6y ago
They are considering the same strategy in Belgium, but with even bigger gap. It seems that it’s the only way to achieve at least some herd immunity before summer.
- collyw 6y ago
  > that it’s the only way to achieve at least some herd immunity before summer. They could have let young healthy people live their lives as normal, as the virus barely affects them. Keep them away from vulnerable people (who could be put into some of the unused hotels for example) and viola, you have decent levels of herd immunity without the expense and destruction of civil liberties. Instead we drag this thing out as long as possible.
  - jackcodes 6y ago
    I think you’re significantly over-estimating the ease of keeping them away from older people.
    - colordrops 6y ago
      Trillions have been spent in the US on bailouts. You could have paid for full time care for every single vulnerable person for a year at that cost, and left everyone else to live normally.
      - seszett 6y ago
        It's not just a question of paying for the care for vulnerable persons. But young people sometimes also want to see their parents at least a few times a year, even if they aren't vulnerable and can care for themselves.
        colordrops 6y ago
        Wouldn't having a nurse or some other full time trained person present be more effective than anything at helping keep "young people" from getting too close? And if these "young people" are out of control, how does lockdown help anyway?
deanclatworthy 6y ago
The whole thing is ludicrous. This strategy also applies to the Pfizer vaccine. By having the booster further apart, it lowers its efficacy from over 90% to around 80%. Given the mistakes the UK government has made along the way, this just fills me with further dread for the situation (I have family there).
- _Gyan_ 6y ago
  Prolonging the 2nd dose interval increases the level of antibodies elicited after the 2nd dose. Dose Interval --> 28 days after dose 1 --> 28 days after dose 2 <6 weeks --> 8,734.08 --> 22,222.73 6-8 weeks --> 7,295.54 --> 24,363.10 9-11 weeks --> 7,492.98 --> 34,754.10 ≥12 weeks --> 8,618.17 --> 63,181.59 from https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-astrazeneca/information-for-healthcare-professionals-on-covid-19-vaccine-astrazeneca https://www.gov.uk/government/publications/regulatory-approv...
  - deanclatworthy 6y ago
    This is in the case of the Oxford/AstraZeneca vaccine. Not the Pfizer.
- BurningFrog 6y ago
  80% protection for 2 people is better that 90% for 1.
  - deanclatworthy 6y ago
    I would agree if this was for the general population but consider the most vulnerable are being vaccinated first. They should be treated with great care and priority and I think it’s unethical for the UK to lower their chances, especially considering the huge numbers of vaccines they are going to have over the coming weeks.
rich_sasha 6y ago
Is this driven by the desire to vaccinate more people, or more to do with the logistics of vaccinating this many people?
- n4r9 6y ago
  I believe it's because preliminary experimental results suggest that the efficacy is greatly increased.
  - n4r9 6y ago
    I can no longer edit this comment, but I was wrong. The reasoning behind the longer gap between doses is logistical, and attempt to get as many first doses in as short a time as possible. It is scientifically unfounded.
BurningFrog 6y ago
This is the way

by kjakm 6y ago

interdrift 6y ago

Good idea indeed!

neals 6y ago

What would be interesting about that is what happens when people are not going to get the booster for various reasons.

jimmygrapes 6y ago
Mutation?
- f6v 6y ago
  Mutations happen all the time regardless of vaccines. The vaccine adds evolutionary pressure and will likely give an advantage to the bearers of particular mutations.
  - ptaipale 6y ago
    If the virus has a smaller base of infected people who grow it, there will be less mutations. From that point of view, the sooner all the world is vaccinated, the better. The risk of a new, more dangerous mutation decreases.
ehsankia 6y ago
I think early data showed that you still get ~60% protection with the first shot (or was that for the Moderna vaccine?) Still, you get some level of immunity, booster only makes it higher.
- maxerickson 6y ago
  The two dose studies provide incomplete information about the single dose efficacy — administration of the second dose ends the data collection for the first dose alone. The data collection also includes the period of time that the body spends responding to the vaccine (so if you get the shot and get infected that day, the shot gets counted as not being effective). And then on the other side of it, they don't have data on how long immunity from a single dose would last. But it's likely that the Moderna and Pfizer vaccines have quite high effectiveness after the initial immune response.
  - ehsankia 6y ago
    Sure, while it's not perfect, the data for those 3 weeks between the first and second shot still can provide a lower bound approximation for immunity, which I assume is where the 60% comes from. The point about how long single dose immunity lasts is fair though.
sgt101 6y ago
Why would they not get the booster?
- jackweirdy 6y ago
  Some will forget, some won’t realise they need it, some will get symptoms the first time and not want it. I don’t expect it will be widespread but humans will be human
- whiddershins 6y ago
  Why do people miss their flight? So much so that airlines can oversell a substantial number of tickets on any given flight and usually the plane departs with empty seats? Why do people get divorced? Why do...
- neals 6y ago
  You must not be a software developer
BurningFrog 6y ago
All that happens is that they have somewhat smaller protection for a shorter time. Unless the vaccine or virus is very different from normal ones.

theflowerpot 6y ago

Recent reports mention 95% effectiveness for the Oxford-AstraZeneca vaccine if the doses are taken 3 months apart, which would be great if confirmed. https://www.businesstoday.in/current/economy-politics/oxford-covid19-vaccine-95-per-cent-effective-if-given-3-months-apart-says-siis-adar-poonawalla/story/426336.html https://www.businesstoday.in/current/economy-politics/oxford... https://www.thetimes.co.uk/article/covid-vaccine-boost-for-millions-as-hospitals-near-breaking-point-vj7fpj2hr https://www.thetimes.co.uk/article/covid-vaccine-boost-for-m...

BillyTheKing 6y ago
they always seem to find additional data supporting this or that. Idk, to me it seems like their reporting is literally all over the place, how did they confirm 95% effectiveness? what's the trial-size, is it also 30k participants like the others? What's the age-distribution of those that took part in this 3-months trial, there are a ton of unknowns with that vaccine, and neither Oxford nor AZ are particularly helpful with clearing those doubts atm.
- grey-area 6y ago
  They have in many ways been more rigorous and transparent than other vaccine trials (weekly swab testing of all subjects, publishing the paper first rather than in the media first, being honest about mistakes made). They don’t control the media reporting. That said it seems the group who received smaller doses by mistake was only 1300, not sure where they got the data on 12 weeks but presumably it’s also a small number or they’d be going with that for everyone. Things should become clearer over time and I hope they can shift to the smaller doses first as it’d give us double the number of initial vaccinations when supplies are limited.
  - BillyTheKing 6y ago
    the just tried to fit in numerous trials into a single trial, whereas Biontech/Pfizer and Moderna were super clear about their trial-architecture and data (same 2-dose regime, given 3 weeks apart), we seem to have a ton of small trials with different data for that Oxford/AZ vaccine. Those 1300 participants who got the half dose full dose vaccine also turned out to be significantly younger than the other group who got the two full-dose regime, making those two groups really difficult to compare (apart from the fact that they were also differing in size) Now we have a new number out there, 90% if the two doses are given 3 months apart, does anyone here now what the trial-size was? the age distribution? The statistical significance for that finding?

f6v 6y ago

They are considering the same strategy in Belgium, but with even bigger gap. It seems that it’s the only way to achieve at least some herd immunity before summer.

collyw 6y ago
> that it’s the only way to achieve at least some herd immunity before summer. They could have let young healthy people live their lives as normal, as the virus barely affects them. Keep them away from vulnerable people (who could be put into some of the unused hotels for example) and viola, you have decent levels of herd immunity without the expense and destruction of civil liberties. Instead we drag this thing out as long as possible.
- jackcodes 6y ago
  I think you’re significantly over-estimating the ease of keeping them away from older people.
  - colordrops 6y ago
    Trillions have been spent in the US on bailouts. You could have paid for full time care for every single vulnerable person for a year at that cost, and left everyone else to live normally.
    - seszett 6y ago
      It's not just a question of paying for the care for vulnerable persons. But young people sometimes also want to see their parents at least a few times a year, even if they aren't vulnerable and can care for themselves.
      - colordrops 6y ago
        Wouldn't having a nurse or some other full time trained person present be more effective than anything at helping keep "young people" from getting too close? And if these "young people" are out of control, how does lockdown help anyway?

deanclatworthy 6y ago

The whole thing is ludicrous. This strategy also applies to the Pfizer vaccine. By having the booster further apart, it lowers its efficacy from over 90% to around 80%. Given the mistakes the UK government has made along the way, this just fills me with further dread for the situation (I have family there).

_Gyan_ 6y ago
Prolonging the 2nd dose interval increases the level of antibodies elicited after the 2nd dose. Dose Interval --> 28 days after dose 1 --> 28 days after dose 2 <6 weeks --> 8,734.08 --> 22,222.73 6-8 weeks --> 7,295.54 --> 24,363.10 9-11 weeks --> 7,492.98 --> 34,754.10 ≥12 weeks --> 8,618.17 --> 63,181.59 from https://www.gov.uk/government/publications/regulatory-approval-of-covid-19-vaccine-astrazeneca/information-for-healthcare-professionals-on-covid-19-vaccine-astrazeneca https://www.gov.uk/government/publications/regulatory-approv...
- deanclatworthy 6y ago
  This is in the case of the Oxford/AstraZeneca vaccine. Not the Pfizer.
BurningFrog 6y ago
80% protection for 2 people is better that 90% for 1.
- deanclatworthy 6y ago
  I would agree if this was for the general population but consider the most vulnerable are being vaccinated first. They should be treated with great care and priority and I think it’s unethical for the UK to lower their chances, especially considering the huge numbers of vaccines they are going to have over the coming weeks.

rich_sasha 6y ago

Is this driven by the desire to vaccinate more people, or more to do with the logistics of vaccinating this many people?

n4r9 6y ago
I believe it's because preliminary experimental results suggest that the efficacy is greatly increased.
- n4r9 6y ago
  I can no longer edit this comment, but I was wrong. The reasoning behind the longer gap between doses is logistical, and attempt to get as many first doses in as short a time as possible. It is scientifically unfounded.

BurningFrog 6y ago

This is the way