There is a large industry in the US that specializes in catering to people that want medications, vaccines, diagnostics, and treatments that are outside the recommended standard of care that medical insurance or public health systems cover. You have to pay for these services directly but the market is competitive so the cost is quite reasonable.

A doctor must sign off on these but that step is mostly performative outside of some narrow exceptions. My impression is that this type of medical care is much more accessible in the US than most other developed countries.