A image posted by 8fact:
This pictured grabbed 11,085 shares and 34,942 likes so far on Facebook. I find it hard to believe.
This is impossible to answer conclusively, since there's no definition provided for either "Zombie", "Apocalypse", or even "possible" (which includes things with miniscule probability, as long as they don't violate laws of nature). Nor of how many scientists said so and if it was in peer reviewed publication.
As such, yes, "some" scientists said that - for some definitions - "zombie" "apocalypse" is "possible".
“I think that the Zombie Virus already exists (almost): Rabies. Infection is nearly 100 percent lethal, i.e. it turns you into the walking dead (for a while at least), and it causes you to change your behavior by reprogramming you to bite other people to spread the infection. Now if only it kept the corpse walking around,” Jonathan D. Dinman, PhD, Professor in the Department of Cell Biology and Molecular Genetics at the University of Maryland, told redOrbit.
Essentially, the rabies virus would need to be slightly altered, or would have to evolve, in a way to keep people kicking and screaming for their next victim rather than killing them off just a few days after symptoms occur.
Cracked.com has 5 other "possible" scenarios, most with nods to scientists discussing the possibility:
growing brain stem from stem cells.