MorHap is a hapten derived from heroin. When conjugated with tetanus toxoid (TT), palm-CV2, and liposomes containing monophosphoryl lipid A (MPLA), it can partially block heroin-induced analgesia and hyperlocomotion in mice. Additionally, MorHap-based conjugates significantly inhibit the binding of HIV-1 to the α4β7 receptor. It is utilized in the research and development of vaccines related to heroin addiction and HIV-1 infection.