Some of the best vampire “transitioning” effects ever are wasted on “Morbius,” perhaps the least interesting and certainly the least consequential action picture ever to wear the Marvel badge.

Jared Leto isn’t awful in the title role. But aside from the effects, everything and everyone around him is indifferent and dull and he proves himself once again as more suited to chewy supporting roles than a lead.

Michael Morbius and the rich kid Lucien, whom re-names “Milo,” met in a Greek sanitarium for children of wealth and the rarest of the rare blood diseases, one that requires a transfusion or two every day to keep them alive. Morbius, plainly a genius, is sent away to school where he vows to “find the cure” for them both.

But while we catch up with the adult Michael as he’s refusing his Nobel Prize, probably for inventing artificial blood, he hasn’t yet figured out how to correct the faulty DNA that keeps him and Milo (the least interesting recent “Doctor Who,” Matt Smith) weak and on crutches.

“Bats” might be the answer, and no, he didn’t get that idea from Bruce Wayne. Vampire bats from the Jurassic Park corner of Costa Rica provide the serum that Morbius takes as the first “human trial” on an offshore Panamanian-flagged freighter. That turns out to be bad news for the hired goons/minions on board.

And this is where “Morbius” pretty much goes off the rails.

It’s bad enough that the good doctor’s scientist/colleague (Adria Arjona) doesn’t know how to pronounce “NoBEL” (Director Daniel Espinosa didn’t get another take?), but for evil henchmen, these mercenary minions seem awfully eager to pull the trigger on their supposed meal ticket.

It’s to no avail. Morbius, transformed to something just this side of “sleeping in coffins,” slaughters them and makes his way back to New York, cursed and yet ethical enough to see that nobody else should try this stuff as he enlists Dr. Bancroft (Argjona) to elude the mustachioed FBI agents (Tyrese Gibson, Al Madrigal) on the case.

“These puncture marks, they look like fangs to you?”

And Morbius must also fend off the rich financier of his experiments — “Milo” — hellbent on availing himself of this hellish “cure” he’s paid for.

A hallmark of many of the less enduring or endurable comic book adaptations is their humorlessness, and “Morbius” is a case in point. The best gag (perhaps from the comic book) is the name of the Panamanian freighter, “Murnau,” the director of the first important vampire movie, “Nosferatu,” F.W. Murnau.

Letolocks is not just about the dreamy eyes and Reagan/Elvis dye jobs. He’s has made it his business to build on the “Method” legend of DeNiro and make his body over for roles. Here, he’s hollow-eyed and emaciated as pre-“transformation” Morbius, chiseled and “cut” afterwards. That’s not why this movie sat on a shelf for so long, waiting for him to beef up or starve himself down. It’s a Marvel picture and there was a pandemic going on so there was no sense leaving money on the table by releasing it to empty cinemas.

But I can’t remember a Marvel movie that went to less trouble giving us an “origin story,” that put more effort into tying the tale into this corner of the Marvel “universe,” and that had less going for it.

Sony makes the best arguments “for” the continued existence of endless iterations of Marvel adaptations, and the best arguments “against” them.

Rating: PG-13 for intense sequences of violence, some frightening images, and brief strong language

Cast: Jared Leto, Adria Arjona, Matt Smith, Tyrese Gibson, Al Madrigal and Jared Harris

Credits: Directed by Daniel Espinosa, scripted by Matt Sazama and Burk Sharpless, based on the Marvel comic. A Sony/Columbia release.

Running time: 1:44