7 ms·

I seriously don't understand this. How does J&J vaccine offer 50%+ protection, but AZ does not? Don't they use the same technology? Don't they target the sam

by raducu 6y ago

I seriously don't understand this. How does J&J vaccine offer 50%+ protection, but AZ does not? Don't they use the same technology? Don't they target the same spike protein?

bushbaba 6y ago
Different tech. J&j isn’t an mrna vaccine
- tebbers 6y ago
  Nor is AZ. The Pfizer is one with the mRNA technology.
  - godelmachine 6y ago
    Pfizer and Moderna use mRNA.
    - elif 6y ago
      neither of those are astrazeneca
- ilogik 6y ago
  neither is AZ
dogma1138 6y ago
The J&J and AZ vaccines both use a similar viral vector with a modified gene. They target the same protein but just like with the mRNA vaccine they usually do not encode the entire protein but rather target specific amino acid chains in various regions of interest on the protein itself. Other differences in the vaccine would be the level and type of immune response generated in general which will be based on the specific viral vector used, dose and regiment, adjuvants etc. The study which measured the J&J efficacy also used a different methodology to this one. Overall this is a very limited study and should be taken in context. Another key part is that the T-cell response for the AZ vaccine group seems to remain intact. >Although the correlation between antibody response and vaccine efficacy is high, which suggests that the neutralizing antibody response is important, T-cell responses may contribute to protection from Covid-19 even in the presence of lower neutralizing antibody titers.32 In a post hoc analysis reported here, we found that in spike-specific T cells that expanded after vaccination with ChAdOx1 nCoV-19, the majority of antigens and epitopes remained intact in recognition of the B.1.351 variant. Until we have data on actual severe cases it seems that the AZ vaccine is still effective at preventing hospitalization and deaths. There were also no tracking of non-symptomatic cases in the study so the actual prevalence of infections in either group is unkown.
- raducu 6y ago
  Thanks, somehow with my software engineering mindset, I thought they somehow just copy&pasted the whole ARN sequence for encoding the spike protein from one virus to the other, and the end result should have been the same, but if its only parts of the S protein, then it makes sense that the outcome will be different.
  - nicoburns 6y ago
    If you want a software analogy, then I think it's more like using regular expressions to try to match inconsistent data, where new data (which is potentially inconsistent in new and exciting ways) is coming in all the time.
    - dboreham 6y ago
      Like a virus scanner.
      - dogma1138 6y ago
        That’s a pretty good analogy the signature isn’t often not a simple hash of the malware but rather a more fuzzy signature based on core functions that are harder to alter without loss of function.
  - dogma1138 6y ago
    I don’t know if they even have enough room to encode the entire protein, that said even if they do it’s quite likely better to focus on specific amino acid chains that relate to specific structural areas of the protein that serve a critical function like interfacing with the receptors these aren’t likely to mutate without loss of function and it increases the likelihood of more targeted immune response. If for example each vaccine selected 30 amino acid chains say 15 common ones and 15 that are varied between vaccines you can end up with vaccines that are more effective against certain mutations than others. Realistically COVID-19 isn’t going anywhere and it will likely become very much endemic and will require a yearly vaccine especially for risk groups just like influenza.
jhh 6y ago
They don't target the exact same protein and they use a different vector.
- dogma1138 6y ago
  J&J uses a similar vector adenovirus just the human type instead of the chimp adenovirus. But yes none of the vaccines use the actual spike protein, they all target slightly different amino acid chains on that protein.
deleted 6y ago
[deleted]
raverbashing 6y ago
They don't translate the spike protein from the original to the target the same way, they might have minor modifications for stability, etc
KaiserPro 6y ago
AZ tested every patient weekly for covid, regardless of self reported symptoms. No other trial did this. Which means the 95% efficacy for phizer/moderna is not actually correct. we have no way of knowing how many were asymptomatic.
- _Microft 6y ago
  Data from Israel suggests that the Pfizer/Biontech vaccine prevents 97% of symptomatic and 94% of asymptomatic cases. (After the intial trial phases had concluded Pfizer only reported how many symptomatic cases were prevented which might be the "95%" number you have in mind)
  - mutagen 6y ago
    Is this the Israel study you're referring to? https://www.nejm.org/doi/full/10.1056/NEJMoa2101765 https://www.nejm.org/doi/full/10.1056/NEJMoa2101765 Just curious, as I've received the Pfizer/Biontech vaccine.
    - _Microft 6y ago
      I think it was more recent than that but I only saw reports about the numbers, not the thing itself.
- orblivion 6y ago
  I assumed every vaccine trial would be testing people regularly. I'm a little shocked if what you're saying is true. Is there not a lot on the line here? Maybe because it was in their interest to hide bad news?
  - linuxftw 6y ago
    These are for-profit companies shielded from liability. They're going to do only the bare minimum to get the product to market. For other classes of drugs, these same companies have been sued and fined for billions of dollars for covering up problems with their drugs. The regulators are beyond incompetent, they're typically industry shills.
manojlds 6y ago
This article talks about at least one tweak that Pfizer, Moderna and J&J do that AZ doesnt https://cen.acs.org/pharmaceuticals/vaccines/tiny-tweak-behind-COVID-19/98/i38 https://cen.acs.org/pharmaceuticals/vaccines/tiny-tweak-behi...
- Throwawayaerlei 6y ago
  I've heard this multiple times, but never with a citation. Can you point us at anything? Trying to prove a negative with searches hasn't worked for me so far, and this vaccine is not a good option for me so I haven't trying looking up and parsing its spike protein nucleotide or amino acid sequence. However all these vaccines you listed coerce a small number of your cells to make spike proteins of whatever sort, which results in bits of them being put on the surface of the cells. I don't know how much of the spike protein gets outside cells, either through direct escape or creation of new viruses, have not looked up the exact details of what J&J and Oxford mean by their viral vectors being replication deficient. That is, they don't produce new viruses that can attack other cells.
ashtonkem 6y ago
Without any knowledge of how vaccines work, it's pretty trivial to determine that there are significant differences between AZ and J&J vaccines; J&J only needs one dose while AZ needs two. That alone implies that there are differences in technology or targeted protein, even if the specifics aren't clear to a non-expert.
- Throwawayaerlei 6y ago
  There are essentially no differences, except J&J's platform had been successful in an European Phase III trial for an Ebola vaccine, but not the one widely used in the last big outbreak, and Oxford's had an 8 year history of Phase I failures. Both replication deficient adenovirus vectors, with the spike protein spliced in, although maybe significantly different versions of the protein. The biggest difference is their goals, Oxford was intended to be a regular vaccine, J&J intended to get the very best protection from a single vaccination, with an initial goal of protecting a billion people in 2021, now increased to 3 billion. Besides J&J's press releases and slow but sure development methodology see the difference in their Phase III trial primary endpoints, here's J&J's https://www.jnj.com/coronavirus/ensemble-1-study-protocol https://www.jnj.com/coronavirus/ensemble-1-study-protocol: To demonstrate the efficacy of Ad26.COV2.S in the prevention of molecularly confirmed, moderate to severe/critical coronavirus disease-2019 (COVID-19), as compared to placebo, in SARS-CoV-2 seronegative adults As in, not stopping people from getting the disease, that's a secondary objective. AZ/Oxford will be hard to track down because they did several different Phase III trails in even more countries. I'd start with ClinicalTrials.gov, look for Primary Outcome Measures and this is a good search to start with: https://clinicaltrials.gov/ct2/results?term=ChAdOx1&cond=Covid19&age_v=&gndr=&type=&rslt=&phase=2&Search=Apply https://clinicaltrials.gov/ct2/results?term=ChAdOx1&cond=Cov... For the US trial: The efficacy of 2 IM doses of AZD1222 compared to saline placebo for the prevention of COVID-19 J&J is also doing a 2 dose 8 weeks apart US based Phase III trail to see what that can accomplish.

by raducu 6y ago

I seriously don't understand this. How does J&J vaccine offer 50%+ protection, but AZ does not? Don't they use the same technology? Don't they target the same spike protein?

bushbaba 6y ago

Different tech. J&j isn’t an mrna vaccine

tebbers 6y ago
Nor is AZ. The Pfizer is one with the mRNA technology.
- godelmachine 6y ago
  Pfizer and Moderna use mRNA.
  - elif 6y ago
    neither of those are astrazeneca
ilogik 6y ago
neither is AZ

dogma1138 6y ago

The J&J and AZ vaccines both use a similar viral vector with a modified gene. They target the same protein but just like with the mRNA vaccine they usually do not encode the entire protein but rather target specific amino acid chains in various regions of interest on the protein itself. Other differences in the vaccine would be the level and type of immune response generated in general which will be based on the specific viral vector used, dose and regiment, adjuvants etc. The study which measured the J&J efficacy also used a different methodology to this one. Overall this is a very limited study and should be taken in context. Another key part is that the T-cell response for the AZ vaccine group seems to remain intact. >Although the correlation between antibody response and vaccine efficacy is high, which suggests that the neutralizing antibody response is important, T-cell responses may contribute to protection from Covid-19 even in the presence of lower neutralizing antibody titers.32 In a post hoc analysis reported here, we found that in spike-specific T cells that expanded after vaccination with ChAdOx1 nCoV-19, the majority of antigens and epitopes remained intact in recognition of the B.1.351 variant. Until we have data on actual severe cases it seems that the AZ vaccine is still effective at preventing hospitalization and deaths. There were also no tracking of non-symptomatic cases in the study so the actual prevalence of infections in either group is unkown.

raducu 6y ago
Thanks, somehow with my software engineering mindset, I thought they somehow just copy&pasted the whole ARN sequence for encoding the spike protein from one virus to the other, and the end result should have been the same, but if its only parts of the S protein, then it makes sense that the outcome will be different.
- nicoburns 6y ago
  If you want a software analogy, then I think it's more like using regular expressions to try to match inconsistent data, where new data (which is potentially inconsistent in new and exciting ways) is coming in all the time.
  - dboreham 6y ago
    Like a virus scanner.
    - dogma1138 6y ago
      That’s a pretty good analogy the signature isn’t often not a simple hash of the malware but rather a more fuzzy signature based on core functions that are harder to alter without loss of function.
- dogma1138 6y ago
  I don’t know if they even have enough room to encode the entire protein, that said even if they do it’s quite likely better to focus on specific amino acid chains that relate to specific structural areas of the protein that serve a critical function like interfacing with the receptors these aren’t likely to mutate without loss of function and it increases the likelihood of more targeted immune response. If for example each vaccine selected 30 amino acid chains say 15 common ones and 15 that are varied between vaccines you can end up with vaccines that are more effective against certain mutations than others. Realistically COVID-19 isn’t going anywhere and it will likely become very much endemic and will require a yearly vaccine especially for risk groups just like influenza.

jhh 6y ago

They don't target the exact same protein and they use a different vector.

dogma1138 6y ago
J&J uses a similar vector adenovirus just the human type instead of the chimp adenovirus. But yes none of the vaccines use the actual spike protein, they all target slightly different amino acid chains on that protein.

deleted 6y ago

[deleted]

raverbashing 6y ago

They don't translate the spike protein from the original to the target the same way, they might have minor modifications for stability, etc

KaiserPro 6y ago

AZ tested every patient weekly for covid, regardless of self reported symptoms. No other trial did this. Which means the 95% efficacy for phizer/moderna is not actually correct. we have no way of knowing how many were asymptomatic.

_Microft 6y ago
Data from Israel suggests that the Pfizer/Biontech vaccine prevents 97% of symptomatic and 94% of asymptomatic cases. (After the intial trial phases had concluded Pfizer only reported how many symptomatic cases were prevented which might be the "95%" number you have in mind)
- mutagen 6y ago
  Is this the Israel study you're referring to? https://www.nejm.org/doi/full/10.1056/NEJMoa2101765 https://www.nejm.org/doi/full/10.1056/NEJMoa2101765 Just curious, as I've received the Pfizer/Biontech vaccine.
  - _Microft 6y ago
    I think it was more recent than that but I only saw reports about the numbers, not the thing itself.
orblivion 6y ago
I assumed every vaccine trial would be testing people regularly. I'm a little shocked if what you're saying is true. Is there not a lot on the line here? Maybe because it was in their interest to hide bad news?
- linuxftw 6y ago
  These are for-profit companies shielded from liability. They're going to do only the bare minimum to get the product to market. For other classes of drugs, these same companies have been sued and fined for billions of dollars for covering up problems with their drugs. The regulators are beyond incompetent, they're typically industry shills.

manojlds 6y ago

This article talks about at least one tweak that Pfizer, Moderna and J&J do that AZ doesnt https://cen.acs.org/pharmaceuticals/vaccines/tiny-tweak-behind-COVID-19/98/i38 https://cen.acs.org/pharmaceuticals/vaccines/tiny-tweak-behi...

Throwawayaerlei 6y ago
I've heard this multiple times, but never with a citation. Can you point us at anything? Trying to prove a negative with searches hasn't worked for me so far, and this vaccine is not a good option for me so I haven't trying looking up and parsing its spike protein nucleotide or amino acid sequence. However all these vaccines you listed coerce a small number of your cells to make spike proteins of whatever sort, which results in bits of them being put on the surface of the cells. I don't know how much of the spike protein gets outside cells, either through direct escape or creation of new viruses, have not looked up the exact details of what J&J and Oxford mean by their viral vectors being replication deficient. That is, they don't produce new viruses that can attack other cells.

ashtonkem 6y ago

Without any knowledge of how vaccines work, it's pretty trivial to determine that there are significant differences between AZ and J&J vaccines; J&J only needs one dose while AZ needs two. That alone implies that there are differences in technology or targeted protein, even if the specifics aren't clear to a non-expert.

Throwawayaerlei 6y ago
There are essentially no differences, except J&J's platform had been successful in an European Phase III trial for an Ebola vaccine, but not the one widely used in the last big outbreak, and Oxford's had an 8 year history of Phase I failures. Both replication deficient adenovirus vectors, with the spike protein spliced in, although maybe significantly different versions of the protein. The biggest difference is their goals, Oxford was intended to be a regular vaccine, J&J intended to get the very best protection from a single vaccination, with an initial goal of protecting a billion people in 2021, now increased to 3 billion. Besides J&J's press releases and slow but sure development methodology see the difference in their Phase III trial primary endpoints, here's J&J's https://www.jnj.com/coronavirus/ensemble-1-study-protocol https://www.jnj.com/coronavirus/ensemble-1-study-protocol: To demonstrate the efficacy of Ad26.COV2.S in the prevention of molecularly confirmed, moderate to severe/critical coronavirus disease-2019 (COVID-19), as compared to placebo, in SARS-CoV-2 seronegative adults As in, not stopping people from getting the disease, that's a secondary objective. AZ/Oxford will be hard to track down because they did several different Phase III trails in even more countries. I'd start with ClinicalTrials.gov, look for Primary Outcome Measures and this is a good search to start with: https://clinicaltrials.gov/ct2/results?term=ChAdOx1&cond=Covid19&age_v=&gndr=&type=&rslt=&phase=2&Search=Apply https://clinicaltrials.gov/ct2/results?term=ChAdOx1&cond=Cov... For the US trial: The efficacy of 2 IM doses of AZD1222 compared to saline placebo for the prevention of COVID-19 J&J is also doing a 2 dose 8 weeks apart US based Phase III trail to see what that can accomplish.