Most bad side effects to vaccines occur pretty quickly.. it's been about 7 months for me now. Why 5 months maximum??
I would guess that at least 70% of our population will eventually get vaccinated if not more. So if somehow you ended up being correct..... we're talking about more than 220 million dead Americans.
Our society would totally collapse.... along with many other societies around the world. Have fun shoveling our corpses.