There's no HIV vaccine because the human immune system doesn't recognize it as a foreign pathogen. All a vaccine does is show the immune system what the pathogen looks like. If the immune system looks at it and says "yeah? so what?", then you don't get immunity. Add to that the fact that there are multiple strains of HIV and all of them rapidly mutate because it has a very unstable genome and that's why there isn't yet a vaccine.
"There has never been a successful corona virus vaccine."
There are 7 coronaviruses known to infect humans. 4 of them cause mild respiratory symptoms and are 4 of the over 200 viruses known to cause what we collectively refer to as the "common cold". There's no vaccine because developing a vaccine for over 200 different viruses would cost a ludicrous amount of money and nobody's paying $20,000 for a cold vaccine.
The other three coronaviruses known to infect humans are SARS-CoV-1 (SARS 2003), MERS-CoV (MERS 2012), and SARS-CoV-2 (COVID-19). Vaccine candidates were developed for SARS 2003 and MERS 2012. Those vaccine candidates made it through phase 1 and phase 2 human clinical trials. Phase 3 trials are massive - involving tens of thousands of paid volunteers - and extremely expensive. By the time we got to phase 3 trials, both SARS 2003 and MERS 2012 had burned out. No patients left means nobody wants a vaccine, which means no market, which means no one funded phase 3 trials.
When SARS-CoV-2 was discovered and its genome mapped, the similarities to SARS-CoV-1 meant that several groups just took the existing SARS-CoV-1 vaccine candidates off the shelf, tweaked them to work with SARS-CoV-2, and put them back into phase 1 and phase 2 clinical trials. That's several (actually I think 12) of the current vaccine candidates for SARS-CoV-2. Now we have multiple vaccine candidates in phase 3 trials, fully funded and being mass produced in parallel so that as soon as they get FDA approval, they can be shipped to your doctor or local pharmacy.
"Just ask the Spanish Flu, H1N1."
Influenza is not a coronavirus. Human beings are more closely related to snails than Influenza is to SARS-CoV-2. But since you asked, the 2009 H1N1 vaccine protects against the 1918 Spanish flu. source
Thank you for your post and that information on why SARS and MERS vaccines were not put to use, but how they have helped bring us that much closer to a vaccine for Covid-19.