Kareem Abdul-Jabbar says LeBron James' use of a COVID Spider-Man meme was so reckless ... it could cost people their lives.
The NBA legend sounded off on the Lakers superstar in a scathing post on Monday ... ripping LeBron for sharing an image that showed three Spider-Mans pointing at each other.
In the meme -- shared by LeBron over the weekend -- the Spider-Mans were labeled "COVID," "Flu" and "Cold" ... and LeBron captioned the image by saying, "Help me out folks."
Abdul-Jabbar said he was so peeved by the implication of the post ... he straight-up called it all a "blow to [James'] worthy legacy."
"By posting the uninformed meme," Abdul-Jabbar said, "LeBron has encouraged vaccine hesitancy which puts lives and livelihoods at risk."
Abdul-Jabbar then implored James to urge people to get the vaccines ... saying his support for the shots "could save thousands of Black lives right now."
As we reported, LeBron is vaccinated ... although he's said he will not pressure people to do the same, telling reporters before the season "That's not my job."
Several NBA players and even some of LeBron's teammates, meanwhile, are continuing to sit out games as COVID cases continue to surge in December.