If you don't have a source for that, you should put it back where it came from.
“Widely accepted take”
“Your inability to provide evidence proves the original take!”
This way of “arguing” has been carefully crafted to prevent any intellectual debate.
Not that I think it will help you, here is an article in Nature on long Covid published in December of 2020 before vaccines were widely distributed: https://www.nature.com/articles/s41591-020-01177-6
5 months before the vaccine came out.