Help me understand what risk you're concerned about. Have there been other mRNA vaccines where an adverse effect showed up in general use that wasn't caught in clinical trials?
This is the very first one, and on an accelerated schedule.
So the answer to your question is unknown, and whoever goes first gets to be part of the large study answering that question.
Personally I'm going to wait for either a conventional vaccine, or at least a year or so by lots of other people. (It helps that I'm 90% sure I had it already, and I'm low risk on top of that.)
Plus severe side effects would have been seen during phase 3 trials anyway.
There haven’t been other approved mRNA vaccines, period. And COVID just isn’t that big of a concern for most people.
There’s every reason for people to decide they don’t want to rush out to get this highly innovative and novel vaccine injected into their bodies.
That said, I'd still rush out and get it. I'm more concerned about the unknowns of Long Covid than I am about the unknowns of the vaccine. https://en.wikipedia.org/wiki/Long_Covid
[0] https://en.wikipedia.org/wiki/COVID-19_vaccine#Clinical_tria...
Medical science is really hard and often unintuitive. There was a great study that came out last week about statins and the nocebo effect [1] which I think is a great example of how hard it is to get good data on clinical symptoms.
But this is exactly the calculus that people will try to perform based on their own perspective on the relative risks. There’s certainly plenty of unknowns and cause for uncertainty.
Unless you are in a high-risk group, this should not be a serious concern. There is almost no evidence for "long covid". The vast majority of the evidence is anecdotal, self-reported clusters of symptoms that resemble other common illnesses:
https://sebastianrushworth.com/2020/11/17/what-is-long-covid...
When you look for higher-quality evidence for the syndrome, you find studies like this one, from the CDC, which defined "long-term" as "symptoms lasting longer than two weeks", where "symptoms" mostly resemble the aftermath of any mild respiratory illness -- fatigue, cough and headache were the most common:
https://www.cdc.gov/mmwr/volumes/69/wr/mm6930e1.htm
As for more specific studies, there have been a few papers about heart inflammation that have been widely circulated, but nearly all of these have been shown to have serious statistical flaws:
https://mobile.twitter.com/ProfDFrancis/status/1298514453642...
The narrative about athletes with heart damage have been shown to be exaggerated, at best, and physicians no longer MRI recommend screening of athletes without outward symptoms:
https://www.upi.com/Health_News/2020/11/04/Heart-inflammatio...
https://www.si.com/college/2020/10/28/big-ten-covid-protocol...
https://images.saymedia-content.com/.image/cs_srgb/MTc2NDI1M...
More generally, physicians are recommending that these sorts of MRI-based fishing expeditions play no role in screening of otherwise healthy people who have recovered from Covid-19:
https://cvctcardiobrief.com/?p=20977
Covid-induced strokes also appear to be a case where cherry-picking statistics has driven a narrative of fear:
https://academic.oup.com/neurosurgery/advance-article/doi/10...
There are currently two clinical trials registered to investigate the question. The earliest we will have any high-quality data on this subject is 2022:
https://clinicaltrials.gov/ct2/show/NCT04411147 https://clinicaltrials.gov/ct2/show/record/NCT04362150
True. But how does that compare to evidence that the vaccine will have serious adverse effects?
I'm simply pointing out that the evidence for "long covid" is incredibly weak. One should use that to adjust their priors for any outcome.