D&D and the rising pandemic

[Eltab]

Another relevant example is the AstraZeneca vaccine itself. Supposedly, it’s only 70% effective- pretty good as vaccines go, but definitely not as gaudily potent as the Pfizer and Moderna ones. But it’s much easier to transport and store, is cheaper to produce, and can be made faster to boot.

(Emphasis added)

This is a good thing; getting a real handle on this disease will involve tools that people can acquire easily and/or use themselves, not require somebody else acting as a gatekeeper.

 

[Garthanos]

Another relevant example is the AstraZeneca vaccine itself. Supposedly, it’s only 70% effective- pretty good as vaccines go, but definitely not as gaudily potent as the Pfizer and Moderna ones. But it’s much easier to transport and store, is cheaper to produce, and can be made faster to boot.

Yes though anywhere standard refrigeration is available might prefer the 94% ones from Moderna.

Another factor we do not know yet duration of protection expectancy it could be a year like the flu or even as awesome ass MMR vaccines.

 

[Dannyalcatraz]

Yes though anywhere standard refridgeration is available might prefer the 90+ ones from Moderna

Yes though anywhere standard refrigeration is available might prefer the 94% ones from Moderna.

Another factor we do not know yet duration of protection expectancy it could be a year like the flu or even as awesome ass MMR vaccines.

My understanding- and please correct me if I’m wrong- is that Moderna’s vaccine is stable for 30 days at standard refrigerator temps. Anything longer requires colder storage.

In contrast, AZ’s vaccine is stable for 6 months at those temps. That’s a significant difference, especially in the developing world or rural areas of more affluent nations.

It could be even more important if C19 turns out to be a virus we have to live with like the flu, with annual shots or other periodic boosters.

 

[Umbran]

And another option could be AstraZeneca followed by a Pfizer/Moderna dose (or vice versa); if that is 95% effective, it stretches the supply.

I don't believe those are interchangable. Certainly, that protocol has not been tested for safety and efficacy, and has not been green-lit by the FDA (or anyone else).

Edit to add: The Pfizer/Moderna vaccine deliver mRNA to your cells in a lipid coating. The AstraZeneca vaccine is using a segment of SARS-COV-2 RNA put in a modified virus. Both induce a cell to make the spike protein from SARS-COV-2, and from that the body initiates an immune response, but they aren't the same, and you can't just swap one for another because it seems convenient.

 

[NotAYakk]

The AstraZeneca vaccine is viral-vector. They are not interchangeable.

So, the point of both the mRNA and the viral-vector is to get the immune system to recognize Covid-19 proteins and kick the crap out of Covid-19.

mRNA works by using your own cells as a bioreactor. The mRNA slides into your cells (it is wrapped in a fragile lipid package do allow that to happen). Your cell starts producing the (utterly useless) spike protein. Your body reacts to the foreign protein and bam, immune response.

The AZ vaccine has a modified chimpanzee virus with RNA that includes "make a spike protein". This virus is very bad at infecting humans, but it can do a bit. So it is injected, it infects some of your cells, and tries to make more chimpanzee virus... and while it is as it, it also makes some of the spike protein.

But because it is so so bad at infecting humans, our body wipes it out really quickly. But it also (hopefully) picks up on that spike protein and learns "spike protein bad!"

The downsides of the AZ live vaccine include that (a) if the person is already immune to that chimpanzee virus, it won't work (this can happen if some other unrelated virus has similar antigens), (b) the person is immune to the chimpanzee virus afterwards, so it cannot be used for this technique ever again.

But in both cases the end goal is exposing the immune system to that spike protein and generating an immune response to it.

The double-exposure idea is that if you are exposed to a virus once, your body cleans it up and might not remember it as important. When primed by one exposure, the second exposure goes into overdrive ("that wasn't just a one off thing, we are under attack! All hands, prepare to repel future boarders!")

As both are trying to do the same thing, it is plausible they can work together.

One possible reason the AZ Chimp virus trick might not work is that that Chimp virus is really, really crappy at infecting humans. So the second dose might get wiped out before it can make any spike proteins, as the immune system is primed from the first dose to repel it.

(This could explain why a half dose followed by a full dose could be more effective; don't prime the immune system as hard against the Chimp virus, and the 2nd invasion gets as far as making spike proteins).

But we could flip this. Give the AZ vaccine. Then the mRNA virus, which doesn't illicit an immune response from the Chimp virus component of the AZ vaccine, ensuring a robust immune response to the spike protein.

I am not a biologist. This is not meant to be a convincing argument. It is mainly meant to say why it is plausible that two different vaccine technologies could work together.

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The AZ vaccine's big advantage is that it is far, far more stable than the mRNA ones.

You could imagine giving someone the AZ vaccine in the field, and get them to come back in 4 weeks to get the mRNA one at a lab; half as much travel as otherwise.

But if the half-dose full-dose of the AZ vaccine is almost as effective as the mRNA one (we can't be certain due to possibility of p-hacking), then doing two passes in the field might still be better.

Also, we are getting so many different vaccine technologies coming down the pipe. Worrying about the quirks of the first 3 might be obsolete in a few weeks. Still, it is fun.

 

[Zardnaar]

Are you gonna get a choice if vaccines? I assume our government will aquire some, they'll be free and you get what's available.

 

[Garthanos]

In contrast, AZ’s vaccine is stable for 6 months at those temps. That’s a significant difference, especially in the developing world or rural areas of more affluent nations.

It could be even more important if C19 turns out to be a virus we have to live with like the flu, with annual shots or other periodic boosters.

Not doubting that AZ may well be the godsend for those developing areas I wonder if the higher quality might be THE difference between needing boosters and not needing them

 

[Umbran]

As both are trying to do the same thing, it is plausible they can work together.

So, "it is plausible" and, "they can just start doing that" are not the same thing. It would take at least several months more testing - that protocol would need its own Phase III trials, at least. By the time that is complete, the other vaccines will be up in full production swing, and there should be no need to "stretch" the supply.

 

[Umbran]

... I wonder if the higher quality might be THE difference between needing boosters and not needing them

So, first off, it isn't necessarily "higher quality". Remember - the reported efficacy of the AZ vaccine is an average of two different dosing regimens. One of those, alone, seemed to be 90% effective, but it wasn't a large enough part of the Phase III study to just lay claim to that number.

It may be that, with the right regimens, the three vaccines are basically equivalent in efficacy.

 

[Dannyalcatraz]

So, the point of both the mRNA and the viral-vector is to get the immune system to recognize Covid-19 proteins and kick the crap out of Covid-19.

mRNA works by using your own cells as a bioreactor. The mRNA slides into your cells (it is wrapped in a fragile lipid package do allow that to happen). Your cell starts producing the (utterly useless) spike protein. Your body reacts to the foreign protein and bam, immune response.

The AZ vaccine has a modified chimpanzee virus with RNA that includes "make a spike protein". This virus is very bad at infecting humans, but it can do a bit. So it is injected, it infects some of your cells, and tries to make more chimpanzee virus... and while it is as it, it also makes some of the spike protein.

But because it is so so bad at infecting humans, our body wipes it out really quickly. But it also (hopefully) picks up on that spike protein and learns "spike protein bad!"

The downsides of the AZ live vaccine include that (a) if the person is already immune to that chimpanzee virus, it won't work (this can happen if some other unrelated virus has similar antigens), (b) the person is immune to the chimpanzee virus afterwards, so it cannot be used for this technique ever again.

But in both cases the end goal is exposing the immune system to that spike protein and generating an immune response to it.

The double-exposure idea is that if you are exposed to a virus once, your body cleans it up and might not remember it as important. When primed by one exposure, the second exposure goes into overdrive ("that wasn't just a one off thing, we are under attack! All hands, prepare to repel future boarders!")

As both are trying to do the same thing, it is plausible they can work together.

One possible reason the AZ Chimp virus trick might not work is that that Chimp virus is really, really crappy at infecting humans. So the second dose might get wiped out before it can make any spike proteins, as the immune system is primed from the first dose to repel it.

(This could explain why a half dose followed by a full dose could be more effective; don't prime the immune system as hard against the Chimp virus, and the 2nd invasion gets as far as making spike proteins).

But we could flip this. Give the AZ vaccine. Then the mRNA virus, which doesn't illicit an immune response from the Chimp virus component of the AZ vaccine, ensuring a robust immune response to the spike protein.

I am not a biologist. This is not meant to be a convincing argument. It is mainly meant to say why it is plausible that two different vaccine technologies could work together.

---

The AZ vaccine's big advantage is that it is far, far more stable than the mRNA ones.

You could imagine giving someone the AZ vaccine in the field, and get them to come back in 4 weeks to get the mRNA one at a lab; half as much travel as otherwise.

But if the half-dose full-dose of the AZ vaccine is almost as effective as the mRNA one (we can't be certain due to possibility of p-hacking), then doing two passes in the field might still be better.

Also, we are getting so many different vaccine technologies coming down the pipe. Worrying about the quirks of the first 3 might be obsolete in a few weeks. Still, it is fun.

I was watching a couple of MDs & pharma types discussing the various vaccines- I believe it was on CNN- and someone asked about getting the Pfizer shot and following up with the Moderna shot instead of the second Pfizer injection.

They first offered the caveat that there was zero research on doing something like that, then continued. Although they are similar, and no one thought it would be dangerous to do do, not one member of the panel thought that would be truly effective.