Comment by dougweltman | Hacker News Reader

Comment by dougweltman | Hacker News Reader

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>Early on, one person got symptoms consistent with typical vaccine side effects, but it was determined that the person had a previously undiagnosed, unrelated disease. Second, there was the highly publicized case where a patient suffered temporary spinal inflammation and recovered shortly. It is unclear if this event is related to the vaccine, ...

This seems rather worrying as these Phase 1 and Phase 2 trials are pretty small, no? What are the odds these patients got this from the vaccine vs whatever else they had going on?

I just can't shake the fact that this particular vaccine seems to have some safety issues. We'll see in Phase 3 if this shakes out, but I would like to understand why governments feel safe about these developments.

This is exactly the kind of question the trials are designed to answer, yes. We know roughly the background incidence rate of diseases, so you can expect some percentage of participants will be affected by those diseases. It's also important to remember your basic statistics fallacies: the question is not, what are the odds that any of our participants come down with MS, which is a very tiny chance. The question is, what are the odds that any of our participants will come down with _any_ background disease, which is a much larger chance. It is very likely to happen, and indeed it does. They still pause the study to run the numbers and make sure the new diagnoses are not outliers from the background rate.

Out of hundreds people picked random, it's not unlikely someone will have some undiagnosed health problem. People get diagnosed with new diseases all the time.

It’s in phase 3 now. I believe all of the above poster is mentioning happened in phase 3 as well.

That's right. Out of ~18,000 people total across 3 countries (UK, South Africa and Brazil), there have been 3 reported events requiring a pause, of which two involved people who got the real vaccine and one who got the placebo.

Keep in mind they pause anytime anything serious happens to anyone in the trial to give them time to make sure the vaccine didn't cause it. Pauses are a good thing - they are a sign they are following the protocols and not just pushing something through.

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