Once hesitant about COVID-19 vaccines, some have changed their minds (NEW YORK) — Although 150 million people have received a COVID-19 vaccine, 34% of Americans are still hesitant about getting the shots and say they are not sure yet, or don’t want the vaccine, according to a recent Kaiser poll. Despite overwhelming data supporting currently authorized vaccines — all of which were found safe and highly effective in large clinical trials and in real life since FDA authorization — many Americans have delayed vaccination, citing a range of reasons. Yet, some who have been hesitant to get the vaccine are changing their minds, they told ABC News.