General > General Technical Chat
Vaccine
madires:
There are already dangerous idiots among us, Two week ago: Dutch Covid test centre hit by suspected bomb attack (https://www.theguardian.com/world/2021/mar/03/dutch-covid-test-centre-hit-by-suspected-bomb-attack).
DrG:
--- Quote from: JohnnyMalaria on March 18, 2021, 12:59:46 pm ---
--- Quote from: jpanhalt on March 18, 2021, 10:55:13 am ---That question has been asked often. First, the J&J vaccine is a viral vector vaccine that uses a replication defective adenovirus. Moderna and Pfizer vaccines do not use a viral vector. They use synthetic liposomes. The latter two vaccines are quite similar and seem to differ mostly in the liposome.
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The liposomal part is just a vehicle for the mRNA that protects the mRNA and enables it to survive the journey to into our cells. Once there, our cells use the genetic information encoded in the mRNA to synthesize proteins identical to those made by the virus. By choosing the correct protein to be made, it can trigger our immune response as if it were the virus itself that was present. The Moderna and Pfizer vaccines are not the same when it come to the mRNA but the concept is the same.
The stability of the liposome is important and a challenge. I worked on similar products about 10 years ago. I suspect Pfizer's difficulties with storage temperature lie with the structure of the liposome and the fact that Pfizer hadn't generated any data to support storage at less extreme temperatures. This has changed.
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I am not a virologist, but I have probably spent 1000 hours with the literature / watching /discussing over the last year. Sadly, it has been consuming, but a fantastic story.
Re: The mRNA vaccines - Agree completely (see #45 in this thread). To me, these two represent a huge breakthrough and are likely to have a huge impact on future vaccines and particularly combo vaccines.
The similarity between the J&J approach and the Pfizer/Moderna approach is that they both use cells to manufacture the protein. The adenovirus approach has been around for a while (tried and true). The Pfizer/Moderna mRNA approach has also been tried for influenza and some others, but unsuccessfully. I think historically, the roots of the approach was probably in some cancer treatments.
The distinction are vaccines which do not instruct the cell to make anything but instead, contain fragments/deactivated virus and the like. I think that Novovax may have some advanced ways to synthesize the substance it uses, but that general approach is the oldest as I see the situation.
I don't know, but I think you are probably right about the stability and Pfizer. But, when you are out their first and the race is all-important, you do not want to risk a failure. I agree that this is changing.
In fact, I believe that we will be taking another covid vaccine in ~ a year, maybe sooner if a a variant becomes dominant. And it will be an mRNA vaccine.
1xrtt:
--- Quote from: Circlotron on March 17, 2021, 11:40:43 pm ---I wonder what would happen if you got the first dose of one brand of vaccine and the second does of a different brand? Would it still work? Would it cause any harm?
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Not sure how it is done in other parts, but around here, you get a vaccination card with the brand, lot number and the date you should return for the second dose. Upon return, you present the card and you get a shot from the same brand.
AFAIK, it´s working, my grandfather and my mother already got two doses and the medical team always show you the label, before.
There was an intense debate as if the vaccination centers should use all doses available, to spread as much population as possible, or keep stock for the second dose and ensure whoever is vaccinate got the full coverage. Eventually, keeping he stock was favored.
DrG:
--- Quote from: 1xrtt on March 18, 2021, 03:30:21 pm ---
--- Quote from: Circlotron on March 17, 2021, 11:40:43 pm ---I wonder what would happen if you got the first dose of one brand of vaccine and the second does of a different brand? Would it still work? Would it cause any harm?
--- End quote ---
Not sure how it is done in other parts, but around here, you get a vaccination card with the brand, lot number and the date you should return for the second dose. Upon return, you present the card and you get a shot from the same brand.
AFAIK, it´s working, my grandfather and my mother already got two doses and the medical team always show you the label, before.
There was an intense debate as if the vaccination centers should use all doses available, to spread as much population as possible, or keep stock for the second dose and ensure whoever is vaccinate got the full coverage. Eventually, keeping he stock was favored.
--- End quote ---
Yes, similar situation (including the debate) in the US. As it is now clear that here we will have enough vaccine soon, the debate part has largely gone away.
As far as mix and match, right now, most place (all that I know about) have only one vaccine. As we get more and more, I am sure some intentional or unintentional mix and match will happen, but not likely with dire consequences.
One issue in the US is the small site vs. mass center. Right now, my state is favoring mass vaccination sites. There have been some problems ("entitled" folks cutting in line in their cars), but they are getting better.
Once I became eligible, I scored an appointment at a smaller Med Clinic. They did a great job! everything was smooth - triage outside - questions at station 1 - nurse at station 2 (filled out card after injection) - off to the anaphylaxis waiting room - out the door.
To get that appointment, I was searching for about an hour a day. 50-60 mile radius - registered with whomever I could - checking with sites (grocery stores and drug store chains) who had appointment software up but (as far as I can tell) no vaccine at this point. Even used browser refresh add-ons....and BTW: I am not happy that some drug stores here "say" you have to be a member of their pharmacy club to get the vaccine. Sure, you have to give a lot of info, including a consent form, as it should be, but at the time of vaccination - but join your club - what is up with that?
tooki:
--- Quote from: NiHaoMike on March 17, 2021, 10:42:36 pm ---
--- Quote from: Zero999 on March 16, 2021, 06:47:46 pm ---I do agree we need to cut our use of antibiotics and develop new ones. It's possible the next pandemic could be caused by an antibiotic resistant bacterium.
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--- Quote from: madires on March 16, 2021, 03:07:07 pm ---Antibiotics are meant to deal with bacteria, not viruses. But it's true that we use way too much antibiotics, not just in human and veterinary medicine but also in industrial livestock farming which is possibly the larger threat.
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Indeed, they should rapidly phase out factory farming. I hope that if factory farming causes another pandemic, it would be one that decimates factory farms but cause little or no harm to humans or sustainably raised animals.
--- Quote from: Nominal Animal on March 17, 2021, 01:53:18 pm ---Particularly funny/weird/sad is that the most effective way to stop the spread of pandemics is to restrict human movement, drastically: no exceptions, even for the super rich or politicians.
So simple, yet so costly and difficult. Proven to save lives, but how do you calculate potential losses, or how much is a single avoidable death worth? How do you balance the near-term loss of life with the long-term loss of life due to increased statistical financial hardships? It is not easy.
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Hence why I'm strongly against reopening schools early, since school has become bloated and overpriced. In its place, we could have online learning services instead. Hands on activities (e.g. science experiments) could be done by sending kits to the students or small workshops could be opened if that's not practical, done in such a way that possible spread would be very limited.
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While I completely agree with you on factory farming, as someone currently in school, I could not disagree more on the online learning idea. We have to do that, and it’s simply no substitute for in-person instruction. It’s less effective, and it creates a lot more work for the teachers to boot.
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