4 ms·

If the trials were comprehensive enough to prove both efficacy and safety, why did they not catch the AZ & JnJ blood clotting issues? One theory is that these p

If the trials were comprehensive enough to prove both efficacy and safety, why did they not catch the AZ & JnJ blood clotting issues? One theory is that these problems primarily afflict those under 40 and this population was not adequately represented in the clinical trials.

bawolff 5y ago
Blood clots happen at a rate of something like 1 in 100,000 people, the trial had something like 20,000 people getting the vaccine in it. Statistically its not surprising it wasn't caught. That the risk is probably not equally distributed just furthers that. For the trial to pick up the blood clots, it would probably have to administer the vaccine to at least half a million people if not more (and you would need other people for the placebo arm). If the size of your trial is a significant portion of a medium sized country, you are not really running a trial but just giving out a vaccine. The trial established it works, and any safety concerns are rare enough that the risk of not just getting covid but getting covid and having severe illness or dying from covid, is higher for most people. There is no 100% garuntees in life, the best we can hope for is showing that the risk is less than the alternative.
- chitowneats 5y ago
  Many of us have preexisting immunity. For that population, the marginal benefit of vaccination is zero. People should be informed about the risks.
  - adrianN 5y ago
    People are informed about the risks.
    - deleted 5y ago
      [deleted]
  - Pyramus 5y ago
    Not really. If you are talking about pre-existing immunity from prior infection, the benefit may be less, and in fact it is recommended not to vaccinate within 6 months of infection. If you are talking about innate immunity or cross-immunity from SARS-Cov-1 it's super rare and hasn't been shown to be relevant in most Western countries. To see the (reduced) benefit even with prior infection just look at the numerous reports of re-infection, be it with a mutated version or otherwise, as well as the numerous reports of prior infected subjects with no or very little antibodies after a couple of months (not the full picture but still). > People should be informed about the risks. Show me one vaccine/medication where people were more informed than about the current Covid vaccines. We are at the point that for most folks it's riskier to drive to the vaccination appointment by car then the actual vaccination.
    - chitowneats 5y ago
      It's also riskier for most folks to drive a car than to catch Covid. I agree that people should look at their specific case and do honest risk/benefit analysis. Most of what I've seen, however, feels more like herd mentality behavior based on one's political leanings. Or people feeling they genuinely don't have a choice, given impending requirements and restrictions from their local governments and employers. Edit: not sure why I'm being downvoted. It should be common knowledge at this point that people in their 20's, 30's, and 40's have a higher risk of automobile accident, suicide, drug overdose, etc, than of covid death.
      - Pyramus 5y ago
        As a European I do not understand what vaccination has to do with political leaning. It's even stranger that in the US pro-life (abortion) seems to correlate with pro-choice (vaccines)? I do understand however that society as a whole says "if you are not willing to take a negligible risk for us, we are not taking risks for you".
        MockObject 5y ago
        We are in an unfortunate state of hyper-polarization where, if one side advocates something, the other side feels compelled to reject it. Unfortunately, this has even extended into medicine. Many such cases! Sad!
  - ptaipale 5y ago
    You can't know what kind of pre-existing immunity, if any, you have against covid.
    - chitowneats 5y ago
      Including after vaccination? If no, why is that different than infection?
      - ptaipale 5y ago
        No, not including after vaccination. When people speak about pre-existing immunity, it's most of the time covid deniers saying there "natural" immunity and vaccines are useless or harmful. (Of course there is also valid discussion of pre-existing immunity, but the more nuanced messages are not as common.)
        chitowneats 5y ago
        Vaccine advocates like yourself can never explain why infection doesn't imply immunity while vaccines do. Sinovac, the Chinese vaccine, is only 50% effective. Pfizer and Moderna are much more effective. J&J is somewhere in between. This is widely accepted but no one seems to ever ask: if I was sick a month ago, where does it fall in that scale? The point of vaccines is to give your immune system a good enough idea of the pathogen, so that your body produces antibodies. Actually contracting the disease does the same thing, unsurprisingly. So the question is how effective is natural infection of COVID-19 at preventing future infection? Surely it's better than Sinovac, a coin flip. No? Do you have any scholarship about this I can look at?
        ptaipale 5y ago
        What? Of course infection induces immunity in case of covid, about on par with mRNA vaccines like Pfizer and Moderna. https://www.nih.gov/news-events/nih-research-matters/lasting-immunity-found-after-recovery-covid-19 https://www.nih.gov/news-events/nih-research-matters/lasting... You don't have similar immunity efficacy studies for actual covid as hou have for vaccines, because infecting people on purpose would be unethical. Note that your wording "coin flip" isn't right for Sinovac, either. 50 % efficacy is not huge but it is still beneficial on population level.

bawolff 5y ago

Blood clots happen at a rate of something like 1 in 100,000 people, the trial had something like 20,000 people getting the vaccine in it. Statistically its not surprising it wasn't caught. That the risk is probably not equally distributed just furthers that. For the trial to pick up the blood clots, it would probably have to administer the vaccine to at least half a million people if not more (and you would need other people for the placebo arm). If the size of your trial is a significant portion of a medium sized country, you are not really running a trial but just giving out a vaccine. The trial established it works, and any safety concerns are rare enough that the risk of not just getting covid but getting covid and having severe illness or dying from covid, is higher for most people. There is no 100% garuntees in life, the best we can hope for is showing that the risk is less than the alternative.

chitowneats 5y ago
Many of us have preexisting immunity. For that population, the marginal benefit of vaccination is zero. People should be informed about the risks.
- adrianN 5y ago
  People are informed about the risks.
  - deleted 5y ago
    [deleted]
- Pyramus 5y ago
  Not really. If you are talking about pre-existing immunity from prior infection, the benefit may be less, and in fact it is recommended not to vaccinate within 6 months of infection. If you are talking about innate immunity or cross-immunity from SARS-Cov-1 it's super rare and hasn't been shown to be relevant in most Western countries. To see the (reduced) benefit even with prior infection just look at the numerous reports of re-infection, be it with a mutated version or otherwise, as well as the numerous reports of prior infected subjects with no or very little antibodies after a couple of months (not the full picture but still). > People should be informed about the risks. Show me one vaccine/medication where people were more informed than about the current Covid vaccines. We are at the point that for most folks it's riskier to drive to the vaccination appointment by car then the actual vaccination.
  - chitowneats 5y ago
    It's also riskier for most folks to drive a car than to catch Covid. I agree that people should look at their specific case and do honest risk/benefit analysis. Most of what I've seen, however, feels more like herd mentality behavior based on one's political leanings. Or people feeling they genuinely don't have a choice, given impending requirements and restrictions from their local governments and employers. Edit: not sure why I'm being downvoted. It should be common knowledge at this point that people in their 20's, 30's, and 40's have a higher risk of automobile accident, suicide, drug overdose, etc, than of covid death.
    - Pyramus 5y ago
      As a European I do not understand what vaccination has to do with political leaning. It's even stranger that in the US pro-life (abortion) seems to correlate with pro-choice (vaccines)? I do understand however that society as a whole says "if you are not willing to take a negligible risk for us, we are not taking risks for you".
      - MockObject 5y ago
        We are in an unfortunate state of hyper-polarization where, if one side advocates something, the other side feels compelled to reject it. Unfortunately, this has even extended into medicine. Many such cases! Sad!
- ptaipale 5y ago
  You can't know what kind of pre-existing immunity, if any, you have against covid.
  - chitowneats 5y ago
    Including after vaccination? If no, why is that different than infection?
    - ptaipale 5y ago
      No, not including after vaccination. When people speak about pre-existing immunity, it's most of the time covid deniers saying there "natural" immunity and vaccines are useless or harmful. (Of course there is also valid discussion of pre-existing immunity, but the more nuanced messages are not as common.)
      - chitowneats 5y ago
        Vaccine advocates like yourself can never explain why infection doesn't imply immunity while vaccines do. Sinovac, the Chinese vaccine, is only 50% effective. Pfizer and Moderna are much more effective. J&J is somewhere in between. This is widely accepted but no one seems to ever ask: if I was sick a month ago, where does it fall in that scale? The point of vaccines is to give your immune system a good enough idea of the pathogen, so that your body produces antibodies. Actually contracting the disease does the same thing, unsurprisingly. So the question is how effective is natural infection of COVID-19 at preventing future infection? Surely it's better than Sinovac, a coin flip. No? Do you have any scholarship about this I can look at?
        ptaipale 5y ago
        What? Of course infection induces immunity in case of covid, about on par with mRNA vaccines like Pfizer and Moderna. https://www.nih.gov/news-events/nih-research-matters/lasting-immunity-found-after-recovery-covid-19 https://www.nih.gov/news-events/nih-research-matters/lasting... You don't have similar immunity efficacy studies for actual covid as hou have for vaccines, because infecting people on purpose would be unethical. Note that your wording "coin flip" isn't right for Sinovac, either. 50 % efficacy is not huge but it is still beneficial on population level.