[rimliu]

Ok, what the mechanism for the long term consequences would be? mRNA itself is gone in days. All what's left is antibodies and some immune memory which should be the same as if you had real COVID. Is that more dangerous than catching covid which may affect your body in many more ways than vaccine which makes your cells to produce a particular protein?

I do not know what the long term effects of the glass of water I just drunk will be.

[marvin]

The thing about "unknown unknowns" is that they are unknown. It's like asking "what could possibly be outside the edge of the map, surely it's more of the same".

This isn't a matter of water flowing downhill through a pipe or a piston moving through a cylinder. Although we have a good understanding of the process, we don't have decades of extensive engineering experience to give us empiric reassurance that there are no gotchas. We didn't put a billion people into airplanes nine months after the first commercial airliner was developed.

Sure, hopefully our current understanding is good enough and there are no long-term side effects. But it's naïve to assume a likelihood of 100%.

Although the elderly and sick have a high likelihood of a serious covid case, young and healthy people are exceedingly likely to have a mild disease. These probabilities are what you have to judge the confidence of long-term vaccine safety against.

[nerdponx]

Who knows? There is so much that we don't understand. And so much of what we claim to understand, we do not understand completely.

[bsaul]

I wonder what field you’re working on, but it seems that you’ve never experienced the difference between theory and practice.

[AndrewBissell]

This is not necessarily specific to the mRNA vaccines, but one potential consequence of population-wide deployment of a 90% effective vaccine might be to create selective pressure for a more virulent strain of Covid without actually eliminating it.

[IfOnlyYouKnew]

By that logic, we'd be ravaged by polio, the plague, tetanus, super-smart bears, and evil spirits.

We should also stop all research.

(I was going to also sarcastically suggest disbanding the military. But that actually happens to sort-of work along the lines you have in mind, because we can disarm tit-for-tat along with everyone else. So what we really need is for COVID to evolve faster, until it is capable of negotiating a truce and make strategic decisions)

[AndrewBissell]

The polio vaccine, as administered, is over 99% effective, which is an order of magnitude difference.

If what I wrote is correct I don't see how it lends itself to "stop all research" as opposed to "wait until we have a more effective vaccine." I'm not even saying it's a greater than 50% probability, but it is a risk.