It wasn’t the opinion of all of them. The ones that spoke out against it were shouted down, because asking questions isn’t allowed in science anymore.
To this day, none of these mainstream doctors can provide a long term study proving the WuFlu shots are safe, because no ten year studies were conducted. So there is no science whatsoever proving they are safe.
But our modern medical industry is totally bought and paid for by Big Pharma, and doctors aren’t allowed to go against them. They must tout the Big Pharma drugs, and of course transgenderism nonsense, and abortion on demand. Any pushback will ruin your career.