Opioid use disorders are a deadly problem worldwide. Pharmacological therapies are effective for abstinence but remain inadequate in the treatment of addiction. Immunotherapy is a promising treatment modality in opioid use disorders. Immunotherapy aims to detect and capture substances by antibodies. Specific antibodies generated against substances bind a psychoactive substance and prevent them from passing through the blood/brain barrier. The psychoactive substance, which cannot pass through the blood brain barrier, will not be able to reveal both the euphoria effect and its side effects such as respiratory depression. Pre-clinical studies are partially sufficient in terms of effectiveness and reliability. However, long term high antibody levels could not be obtained in the blood following the vaccinations. The number of studies on opioid vaccines that have reached the clinical research level is very low. Thus, the effect of matter in the brain is prevented from occurring. Although effective results were obtained in preclinical studies, long-term high antibody levels could not be achieved in the blood. The number of studies that have reached the level of clinical research is insufficient. Efforts to increase the effectiveness of vaccines are ongoing. Although positive results are obtained in these studies, there are some difficulties vaccination studies. The financial burden of vaccine development, the use of multiple substances in opioid dependents, immune system suppression by the opioids, and changes in the degree of opioid purity are some of them. Despite all these difficulties, immunotherapy is the treatment that the researchers and patients expect with hope.