Just to circle this back to the initial comment, HPV is a DNA virus, but yes, the vaccine is effective and greatly reduces the risk of awful cancers in both men and women. I plan to have both my children vaccinated when they are old enough.

There's been decades of work on an HIV vaccine, obviously. One of the most promising a bit over a decade ago was able to stimulate antibodies quite well just like the one in the story - maybe event the one u/redrightreturning got, who knows. Sadly, it turned out that individuals who had been vaccinated were more likely to get HIV. Why?, and the perpetual problem with HIV vaccines - HIV targets white blood cells. When you vaccinate someone, you're potentially instructing the immune system to find the virus, and at the same time the virus now has a backdoor access key to get into those white blood cells (the antibodies you made with the vaccine).

Making vaccines for most viruses is not overly complicated - we have many of the tools and approaches hammered out pretty well now, but there's still areas that can be improved (targeting CD4 vs. CD8 T-cell responses for one). mRNA vaccines were the next frontier for covid, but there are other, more tried approaches that work OK too - the ChAdOx approach is pretty common, and Sinovac is as simple as it gets. One virus, a DNA virus in fact, that has been especially problematic is African swine fever. No direct concern to you or me, but one of the most economically important viruses of agriculture out there. All sorts of new tech has been tried with that virus, with mRNA vaccines under development now...but I'm not incredibly hopeful.

Some viruses, though rarely, just don't respond to any of the vaccine approaches we've come up with.