With opioid overdose deaths climbing every year, researchers are exploring an unconventional tool: vaccines. Rather than preventing infection, opioid vaccines train the immune system to neutralize drugs like fentanyl before they reach the brain, reducing overdose risk in high-risk populations. We examine the promising preclinical results behind anti-fentanyl and anti-oxycodone vaccines, and why they remain only one piece of a broader strategy against opioid use disorder and a
