A lot of this has to do with social trust and politicization. For a number of reasons, going back to the early days of Tuskeegee syphilis studies, public health in the U.S. is viewed by large portions of the public as imperious, corrupt, unaccountable, beholden to big business and/or utopian ideologies, and is generally viewed with suspicion by many on the left and on the right. African Americans have the lowest vaccination rates by race.
But this is across the board. Prior to covid, for example, the ground zero for anti-vaccination movements was Marin County, California -- one of the most liberal counties in the nation, where only 50% of students in some schools were given smallpox/measles vaccines and there were outbreaks as a result.
Given this environment, American public health authorities should recognize their credibility gaps and embark on a program of transparency, consistency, accountability, and humility.
Unfortunately this is the exact opposite of their behavior. There remains deep ties between public health agencies and large pharmaceutical companies, public health officials continue to invest in and hold patents owned by companies that fall under their purview, there is still a revolving door between the two, there is very little transparency, no accountability for funding research in foreign labs to skirt US safety rules and congressional restrictions, public health officials were widely photographed in meetings without wearing masks (surrounded by masked servants), and they adopt imperious tones demanding draconian punishments for deviations from policy as well as calling for censorship of their critics. Fauci's declaration that "I am the science" is an example of this imperious attitude, which is frankly disastrous.
Until there is real reform, the U.S. is going to maintain a huge credibility gap vis-a-vis other nations, which will make public health efforts that much harder here, and will also lower long term public health outcomes.