First-of-its-kind fentanyl vaccine targets overdoses before they start

A vaccine to protect against fentanyl’s deadly effects is headed for clinical trials in humans.

The vaccine, which showed positive results in studies of mice and rats, is designed to block fentanyl from entering the brain, blocking its effects and preventing overdoses.

If approved, it would become the first treatment to prevent overdoses of fentanyl, which is the leading cause of drug overdose death, statistics show. This is different than treatments like naloxone, which reverse the effects after an overdose.