Vaccine immunogenicity in injecting drug users: a systematic review.

Injection drug use is a prevalent global phenomenon; one not bound by a country's level of development or geographical location. Injection drug users (IDUs) are at high risk for a variety of parenterally acquired and transmitted infections. Licensed vaccines are available for some of these infectious diseases, such as tetanus, influenza, and hepatitis A and B viruses; however, there have been conflicting reports as to their immunogenicity in IDUs. We summarise the lessons learned from studies evaluating the immunogenicity of vaccination strategies in IDUs. A common theme across these diseases is that although there is a tendency towards decreased antibody responses after immunisation, there is no conclusive evidence linking these observations to a decrease in clinical protection from infection. There is a clear need for definitive studies of vaccination strategies in IDUs; however, a synthesis of the available published evidence suggests that immunisation does result in effective clinical protection from disease in this population. The inclusion of IDUs as a high-risk study population in future trials evaluating HIV and hepatitis C virus vaccines will help to assess the immunogenicity of candidate vaccines against parenteral exposure, and also to evaluate the efficacy of candidates as promising antigens become available.

Duke Scholars

Author Christopher Charles Beyrer Medicine, Infectious Diseases