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There’s an increasing likelihood that the AZ vaccine will arrive too late to the party in the US and will be the least effective of all the vaccines approved by

There’s an increasing likelihood that the AZ vaccine will arrive too late to the party in the US and will be the least effective of all the vaccines approved by the FDA. We don’t know the latter yet for sure, J&J’s data is supposed to come out in a few weeks, but if that comes to fruition it will be a HUGE misstep for AZ. It’s unclear at what level herd immunity will be reached with Covid, more recent estimates are trending towards the 80-90% of the population range. If that’s the case then the AZ vaccine may not be good enough to eradicate the disease, even with full vaccination of the population.

ggm 6y ago
I don't think you appreciate the economics of vaccination or the time it will take to get through the population on current rates. A 4C storage vaccine can be deployed in drugstores, carparks, by clinicians with normal training. The -60C vaccine demands ridiculously low wastage rates and a 30min hold time in case of anaphylaxis which is running anywhere up to 5x normal expected rates because of PEG. There is an increasing likelihood several vaccines will be used by every country, almost continuously for the next decade.
- woeirua 6y ago
  Both the J&J and moderna vaccines can be stored at much warmer temperatures. Pfizer likely can as well but they haven’t done the testing to verify that yet. I’m not saying that AZ’s stocks of vaccine are going to be thrown out by any measure.
  - ggm 6y ago
    Its too early to say, basically. Enough locked in sales that absent a huge problem in the field, all the six to ten leading vaccines are going to be used at high scale for years. There's massive competition in fluvax. We don't all use a single source, never have. Since the days of penicillin there was a standard to measure against for efficacy and you can source it as you see fit.
cm2187 6y ago
In my mind having some diversification in vaccines is a good thing. I understand we never used a mRNA vaccine on humans at scale before, so it is still somewhat experimental. It may work great but we can’t completely exclude an unexpected side effect in the long term. Also a few weeks shouldn’t change anything. We are talking about a 6-12 months vaccination campaign. I suspect the 80% number you mention is to eradicate the virus. I think at this stage it is a bit unrealistic. Between poorer countries that will not be able to vaccinate everyone and animals which can carry this disease, I would imagine the virus is here to stay. I think the primary objective is for it to cease to be a major public health issue. That it keeps contaminating people at low intensity in the background shouldn’t be a major concern.
SomeoneFromCA 6y ago
Herd immunity rate is directly dependendent on Rt. If something spreads faster, and Rt is therefore higher herd threshold will be higher too. I think the UK variant is the cause of recent updates on herd immunity percentage.
- irq11 6y ago
  And nobody has any idea if that variant actually affects the transmission rate, let alone what impact it might have on “Rt”. Speculation about this is irresponsible, at the very least. Moreover, we have eradicated exactly one human disease in all of history, and it took a couple hundred years of effort. Eradication is not the goal. Immunize the most vulnerable people in the population (those over 65 and/or with certain co-morbidities), and the death rate for this virus will be dramatically reduced long before any herd immunity threshold is achieved.
  - dragonwriter 6y ago
    > And nobody has any idea if that variant actually affects the transmission rate People very definitely have ideas: https://www.bmj.com/content/371/bmj.m4944 https://www.bmj.com/content/371/bmj.m4944 :: Is the new variant more infectious? Yes, according to a review of the current evidence by the UK’s New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG). Its 18 December report said that the rate of transmission of the variant, known as B.1.1.7 or VUI 202012/01 (variant under investigation, year 2020, month 12, variant 01), was 71% (95% confidence interval 67% to 75%), higher than for other variants, and that it may also have a higher viral load.1 While previous variants have emerged without clear evidence of having a selective advantage, the report noted, the “emergence and subsequent dominance” of this new variant in a period of relatively high prevalence indicated that it does have a “selective advantage over other variants.”
    - irq11 6y ago
      Yes, I’ve read the original report upon which that claim is based. They make it utterly clear that the evidence is weak, and that genetic variants can achieve high frequency even if selectively neutral: https://khub.net/documents/135939561/338928724/New+SARS-COV-2+variant+-+information+and+risk+assessment.pdf/b56d4591-0466-1a18-28dc-010e0fdeef53?t=1608569319930 https://khub.net/documents/135939561/338928724/New+SARS-COV-... This slide deck puts it in perspective: there’s a specific mutation that is increasing in prevalence in a certain surveillance network, there’s a hypothesis about why it might lead to increased spread, and it requires more investigation. That’s it. Any claim of knowledge about impact on Rt is simply wild exaggeration of the data. This is a case where if you don’t understand the field, you have no ability to judge the quality of the claim being made. People are irresponsibly reading second-hand sources, and quoting numbers out of context. Other people quote those sources, and before long, the snake is eating its own tail. I would wager that the author of that BMJ piece never even read the presentation I quoted above (even though it’s the cited source by NERVTAG for the “genetic evidence” claim in the brief whitepaper that the authors do cite). This stuff is almost 100% speculation.
onetimemanytime 6y ago
Can a person (in poorer countries) get this first and then Moderna /Pfizer a year or so later? Will the second vaccine cause problems? Even 60% is better than nothing. Add the percentage that already passed the virus and you get a decent % that no longer get sick or transmit. Not a bad thing, for now.
- brmgb 6y ago
  Unlikely to cause problem. Giving people multiple vaccines using different vectors is common and tend to help in reaching immunity. Tests are currently under way for dual inoculation of the Oxford and Russian vaccines. A multi-vaccines protocol is unlikely to include any of the RNA based one however. They are just too expensive and too difficult to store. But a combination of the more traditional is likely.

ggm 6y ago

I don't think you appreciate the economics of vaccination or the time it will take to get through the population on current rates. A 4C storage vaccine can be deployed in drugstores, carparks, by clinicians with normal training. The -60C vaccine demands ridiculously low wastage rates and a 30min hold time in case of anaphylaxis which is running anywhere up to 5x normal expected rates because of PEG. There is an increasing likelihood several vaccines will be used by every country, almost continuously for the next decade.

woeirua 6y ago
Both the J&J and moderna vaccines can be stored at much warmer temperatures. Pfizer likely can as well but they haven’t done the testing to verify that yet. I’m not saying that AZ’s stocks of vaccine are going to be thrown out by any measure.
- ggm 6y ago
  Its too early to say, basically. Enough locked in sales that absent a huge problem in the field, all the six to ten leading vaccines are going to be used at high scale for years. There's massive competition in fluvax. We don't all use a single source, never have. Since the days of penicillin there was a standard to measure against for efficacy and you can source it as you see fit.

cm2187 6y ago

In my mind having some diversification in vaccines is a good thing. I understand we never used a mRNA vaccine on humans at scale before, so it is still somewhat experimental. It may work great but we can’t completely exclude an unexpected side effect in the long term. Also a few weeks shouldn’t change anything. We are talking about a 6-12 months vaccination campaign. I suspect the 80% number you mention is to eradicate the virus. I think at this stage it is a bit unrealistic. Between poorer countries that will not be able to vaccinate everyone and animals which can carry this disease, I would imagine the virus is here to stay. I think the primary objective is for it to cease to be a major public health issue. That it keeps contaminating people at low intensity in the background shouldn’t be a major concern.

SomeoneFromCA 6y ago

Herd immunity rate is directly dependendent on Rt. If something spreads faster, and Rt is therefore higher herd threshold will be higher too. I think the UK variant is the cause of recent updates on herd immunity percentage.

irq11 6y ago
And nobody has any idea if that variant actually affects the transmission rate, let alone what impact it might have on “Rt”. Speculation about this is irresponsible, at the very least. Moreover, we have eradicated exactly one human disease in all of history, and it took a couple hundred years of effort. Eradication is not the goal. Immunize the most vulnerable people in the population (those over 65 and/or with certain co-morbidities), and the death rate for this virus will be dramatically reduced long before any herd immunity threshold is achieved.
- dragonwriter 6y ago
  > And nobody has any idea if that variant actually affects the transmission rate People very definitely have ideas: https://www.bmj.com/content/371/bmj.m4944 https://www.bmj.com/content/371/bmj.m4944 :: Is the new variant more infectious? Yes, according to a review of the current evidence by the UK’s New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG). Its 18 December report said that the rate of transmission of the variant, known as B.1.1.7 or VUI 202012/01 (variant under investigation, year 2020, month 12, variant 01), was 71% (95% confidence interval 67% to 75%), higher than for other variants, and that it may also have a higher viral load.1 While previous variants have emerged without clear evidence of having a selective advantage, the report noted, the “emergence and subsequent dominance” of this new variant in a period of relatively high prevalence indicated that it does have a “selective advantage over other variants.”
  - irq11 6y ago
    Yes, I’ve read the original report upon which that claim is based. They make it utterly clear that the evidence is weak, and that genetic variants can achieve high frequency even if selectively neutral: https://khub.net/documents/135939561/338928724/New+SARS-COV-2+variant+-+information+and+risk+assessment.pdf/b56d4591-0466-1a18-28dc-010e0fdeef53?t=1608569319930 https://khub.net/documents/135939561/338928724/New+SARS-COV-... This slide deck puts it in perspective: there’s a specific mutation that is increasing in prevalence in a certain surveillance network, there’s a hypothesis about why it might lead to increased spread, and it requires more investigation. That’s it. Any claim of knowledge about impact on Rt is simply wild exaggeration of the data. This is a case where if you don’t understand the field, you have no ability to judge the quality of the claim being made. People are irresponsibly reading second-hand sources, and quoting numbers out of context. Other people quote those sources, and before long, the snake is eating its own tail. I would wager that the author of that BMJ piece never even read the presentation I quoted above (even though it’s the cited source by NERVTAG for the “genetic evidence” claim in the brief whitepaper that the authors do cite). This stuff is almost 100% speculation.

onetimemanytime 6y ago

Can a person (in poorer countries) get this first and then Moderna /Pfizer a year or so later? Will the second vaccine cause problems? Even 60% is better than nothing. Add the percentage that already passed the virus and you get a decent % that no longer get sick or transmit. Not a bad thing, for now.

brmgb 6y ago
Unlikely to cause problem. Giving people multiple vaccines using different vectors is common and tend to help in reaching immunity. Tests are currently under way for dual inoculation of the Oxford and Russian vaccines. A multi-vaccines protocol is unlikely to include any of the RNA based one however. They are just too expensive and too difficult to store. But a combination of the more traditional is likely.