You could say the same about teen pregnancy being a practically solved problem, except there is still the problem of teen pregnancy. Or even something more mundane as driving consistently safely all the time to solve the problem of accidents.
If everyone was disciplined all the time in regard to everything, many problems in the world would simply not exist. But we live in reality where for whatever reason, people don't know to do something, or they do know and they're just not disciplined, or they make a mistake due to extenuating circumstances. And I would expect that the vast majority of people would oppose any idea of somehow punitively "dealing with" people who get some things wrong.
So I would say that it's very evidently not a practically solved problem, because if it were we wouldn't be looking to solve it still.
Within this reality, a vaccine is a great additional tool at solving the problem of preventing the spread of HIV.
Taking teen pregnancy as an example: we have the tools to avoid it. We have condoms, we have birth control, we have the morning after pill, we have abortion. We have all the tools -- are more tools really going to help? The fact that teen pregnancy is still an issue is not because we lack the tools to solve it.
HIV prevention is similar. We already have the tools. We have condoms. We have PrEP. Sure, a vaccine would be nice, but if someone is unwilling to go on PrEP, why would they suddenly be willing to get a vaccine?
Another tool isn't going to hurt, obviously. But it also isn't the #1 highest leverage place to be spending our time if the goal is to reduce HIV transmission. (It is, however, a great use of time to develop a vaccine if you're profit-motivated. HIV prevention is a massive business. 1 year of PrEP in the US costs $20-30k, although luckily ACA mandates $0 copay. I could imagine a $50k HIV vaccine being a blockbuster drug especially if ACA also mandates $0 copay - tons of money to be made! Ugh)
Edit: To be clear, I'm excited there's a promising vaccine. However, I am not getting my hopes up that a vaccine will magically cure all of the social/political issues getting in the way of a vaccine actually being widely distributed and administered.
> And I would expect that the vast majority of people would oppose any idea of somehow punitively "dealing with" people who get some things wrong.
Of course, and for good reason. The ones who know for a fact they are right, might in fact be wrong or malicious.
I thought the current panic was that young people (not necessarily teens) weren't having enough kids?
Right, but we know that HIV/AIDS essentially is a solved problem in rich countries, that the mentioned interventions are readily available in rich countries, and the only reason HIV transmission is high in poor countries is because, well, they're poor. We (humanity as a whole) have plenty of money, we could fund these things, we simply choose not to.
I would caution against making an allusion to self control. It would be very cruel to act as if people who get a disease through no fault of their own could have avoided it, and most people who contract HIV could not. You may not have intended to make that allusion, but you did.
> So I would say that it's very evidently not a practically solved problem, because if it were we wouldn't be looking to solve it still.
This is obviously not what is meant by "practically solved problem". Everybody knows it is not actually solved.