This is a great podcast that explains why vaccination during a pandemic is going to push the virus to mutate around, and become more dangerous and infectious.

Of course these mRNA synthetic nucleotides aren't vaccines, but the point is anything done at a scale like this during a pandemic will put pressure on the virus to mutate around it. You can never jab 100% of the people in one day, and in the meanwhile will be people who get infected soon after being injected, and they will evolve the immune-evading variants.

As Bret explains, most people think vaccinating before a pandemic and during a pandemic are the same thing, but the second one is a serial passage experiment to push it to evolve towards complete immune escape and more infectiousness.

In my opinion the virus will have total Generation 1 mRNA escape in less than 6 months. The next wave will be Biblical.

Here's a short paper that describes the concepts well: https://www.geertvandenbossche.org/post/seriesofpublications