Housing conditions and microbiota environment do not affect the efficacy of vaccines for treatment of opioid use disorders in mice and rats.

Anti-opioid vaccines are a novel strategy to treat and prevent opioid use disorder (OUD) and overdose. Because patients with OUD or other substance use disorders may be affected by other co-morbidities, such as infection or depression, it is important to test whether vaccine efficacy is affected by factors that may impact individual immunity. To this end, this study tested whether housing conditions would affect the efficacy of two lead vaccine formulations targeting oxycodone and fentanyl in male mice and rats, and further analyzed whether differences in the gastrointestinal (GI) microbiome would be correlated to either vaccine efficacy or housing conditions.