5 ms·
It's important to note that the AstraZeneca vaccine is adenovirus based [0], not mRNA based like the Pfizer and Moderna candidates. It was to be expected that t
by aphextron 6y ago
It's important to note that the AstraZeneca vaccine is adenovirus based [0], not mRNA based like the Pfizer and Moderna candidates. It was to be expected that this approach could cause more complications. mRNA vaccines have their own issues, but they do not involve live viruses being injected [1]. Instead they use lipid nanoparticles as a substrate to enter the body's cells [2].
[0] https://www.astrazeneca.com/media-centre/press-releases/2020/astrazeneca-and-oxford-university-announce-landmark-agreement-for-covid-19-vaccine.html https://www.astrazeneca.com/media-centre/press-releases/2020...
[1] https://www.phgfoundation.org/briefing/rna-vaccines https://www.phgfoundation.org/briefing/rna-vaccines
[2] https://www.nature.com/articles/s41586-020-2639-4 https://www.nature.com/articles/s41586-020-2639-4
- mrfusion 6y agoSo how does this one work? Live adeno’s?
- aphextron 6y ago>So how does this one work? Live adeno’s? Yes. It uses a live (weakened) chimpanzee adenovirus to insert the spike protein. https://www.drugs.com/history/azd1222.html https://www.drugs.com/history/azd1222.html
- mrfusion 6y agoDo the adenos actually have to infect the cells to produce the spikes?
- dogma1138 6y agoYes, they don’t replicate virons that could be assembled the virus was modified to mainly replicate the spike proteins since your cells send samples of anything they replicate to the cell wall for your immune system to monitor and sample this is how the adaptive immune response is achieved.
- kurthr 6y agoExactly, for strong long term response you want T-cell involvement.
- im3w1l 6y ago> cells send samples of anything they replicate to the cell wall for your immune system to monitor Wow nature is truly a marvel! How do they do that? Or where could I read more?
- deleted 6y ago[deleted]
- nextos 6y ago> Wow nature is truly a marvel! How do they do that? Or where could I read more? Read about the HLA/MHC class I pathway. And also about JAK/STAT1, which is how cells decide if they are infected.
- ethbr0 6y agoThe chimpanzee adenovirus is used as a vector, with its payload replaced with instructions to manufacture SARS-CoV-2 spike protein. Virus enters body, hopefully survives immune system long enough to insert instructions into your cells, your cells churn out tons of copies of coronavirus spike protein, your immune system sees the surfeit of spike protein and develops a response (antibodies and T* cells). https://blogs.sciencemag.org/pipeline/archives/2020/04/23/a-close-look-at-the-frontrunning-coronavirus-vaccines-as-of-april-23 https://blogs.sciencemag.org/pipeline/archives/2020/04/23/a-...
- karmicthreat 6y agoThought Emporium has a decent video where he modifies an Adenovirus to inject the lactase gene into the cells of his intestinal tract. https://www.youtube.com/watch?v=J3FcbFqSoQY https://www.youtube.com/watch?v=J3FcbFqSoQY
- kevin_b_er 6y agoIt could still be an immune system misfire. A vaccine is trying to create an large immune system response enough that the real infection is thwarted. With that, a misfire can happen with any vaccine attempt, because an immune response is what's required.
- EForEndeavour 6y ago> rather than producing them outside the body and then injecting them That's not what the Oxford/AZ vaccine does, is it? From what I understand, it's a viral vector vaccine engineered to deliver DNA that encodes the SARS-CoV-2 spike protein into human cells and induce them to express the protein, stimulating the immune response. The plan was never to introduce spike protein "produced outside the body." The mechanism of action is getting the body to produce spike protein and learn to attack it as foreign. If the Oxford/AZ vaccine doesn't "take advantage of your own cells to produce the spike protein," I don't know what does. https://labblog.uofmhealth.org/rounds/top-5-covid-19-vaccine-candidates-explained https://labblog.uofmhealth.org/rounds/top-5-covid-19-vaccine...
- sudosysgen 6y agoYes, that was made in comparison to conventional vaccines that either use inactivated viruses or viral proteins
- dogma1138 6y agoPlenty of vaccines both today and historically used LAV or other natural strains of the virus when possible.
- kurthr 6y agoYes, the ChAdOx is an adenovirus carrier (chimp? to minimize human pre-infection) while Moderna and BioNTech as the parent states involve injection of mRNA (not DNA although there are other vaccines that do that) lipid particles that human cells then generate spike protein to simulate viral infection. There are still other attenuated virus and other vaccines under development, they just haven't reached Phase III. Novavax even does something similar to what you describe (spike proteins with adjuvant), but it's also not past Phase I/II.
- axaxs 6y agoI think COVID is going to be make or break for mRNA, at least for infectious disease. It's either going to usher in an exciting new era of treatments, or we're going to see a lot of funding dry up and shops close. I for one obviously hope for the former, but given the prior actions/statements of some in Inovio, Moderna, et al, it gives me pause.
- raxxorrax 6y agoYou cannot roll out such a vaccine on a large scale within a at least a year. Far too many unknowns compared to the virus itself.