Scientists from the Scripps Research Institute in California are developing a vaccine that could bring an end to the opioid crisis sweeping America. Drug overdoses have led to over 60,000 deaths in the United States in 2016, but a combination vaccine that offers protection from the effects of both heroin and the synthetic opioid fentanyl  — which is up to 100 times more powerful than morphine  — is currently under development, and could help curb addiction and possibly even prevent fatal overdoses. The findings were presented at last week's meeting of the American Chemical Society (ACS) in Washington in the United States, and represent the latest attempts to address the opioid crisis. The opioids are made of tiny molecules that the body's immune system doesn't recognise and so doesn't fight them, making it difficult to develop vaccines to counter their affects. To stimulate the immune system, the researchers designed small molecules called haptens that resemble the opioids, but have proteins called epitopes attached that act as binding sites for antibodies produced by the immune system. Once the immune system is trained to recognise the molecules that look like opioids, it will send out antibodies that cling to the drugs, preventing them from crossing the blood-brain barrier. To find out more got to Opioid Vaccines Could Make the Brain Immune to Heroin.