Firstly HIV/AIDS only affected a small proportion of the world population and there was probably not a massive interest in getting a vaccine as other drugs became available to treat the disease.The HIV taken over 10 years to produce and has not cured it only stablised it so in 10 months they can cure a virus come on...........
Covid19 affects everyone on earth so almost every research lab and major drug company was in a race to find a vaccine. Corona has been around for a long time before C19 and other flu vaccines already existed so it is unsurprising that this particular corona has been conquered