Planet of the Vampires is one of those flicks I've read about for decades, but for whatever reason have never seen. I fixed that by acquiring a copy and giving it a good going over, a few times in fact with and without commentary. I learned a lot I didn't know or more likely forgot.
This movie seems no doubt to have been an influence on the blockbuster science fiction horror film Alien. While I've watched that one many many times since first finding it in the theaters so many years ago, it's not noted by its creators that Planet of the Vampires was a resource, or at least not that I remember. But the similarities are many.
Whether the Atlas-Seaboard comic book Planet of Vampires was inspired by the movie (at least in title) is unknown, but there are many connections between Atlas-Seaboard comics and films of the time. But there is one thing missing from the movie which is seen in abundance in the comic book, a tale of four astronauts returned to Earth to find civilization demolished, lots of vampires. There are none in the movie despite its title. There are are intelligent and malevolent undead, but they are more akin to zombies than vampires.
But back to the Alien-Planet of the Vampires connections. A space crew answers a distress call and lands on a forbidding planet to find a derelict space ship occupied by long-dead giant astronauts who seem to have fallen prey to something threat which may well likely still be active. In this one directed by Mario Bava, we have our hero Barry Sullivan lead his crew into danger and they pretty quickly start to fall as the threat reveals itself. There are some nifty secrets, so I won't say much more, but this one is a highly recommended and I kick myself that it took so long for me to figure that out.