It's frankly nuts that we don't make preventative medicine for transmissable diseases free in the rich world. It's so obviously in the collective interest to reduce prevalence.
There have been many failed attempts at developing suppressive, curative and preventative medicine against HIV over the decades, and not all of that was funded by charities or government grants that don't expect repayment - especially not the later stage trials.
We don’t, or at least not everyone agrees we do. Some of us think that we only have an institution that administers peace and order, and believe that pursuing the good is a private, voluntary concern.