Trial, error and breakthrough: A review of HIV vaccine development

With more than 35 million infected in over thirty years, the HIV pandemic has been a unique challenge to the scientific community. The development of effective anti-retroviral therapy has decreased morbidity and mortality of those infected with HIV, but a comprehensive approach that includes effective prevention strategies will be needed to curb this unique pandemic. Vaccines remain the best option, but the development of a safe and effective preventive HIV vaccine has defied decades of research. Over 30 products have been tested in more than 85 trials, but no safe and effective vaccine has been developed yet. Despite these setbacks, these decades of research have broadened the understanding of HIV immunopathogenesis and closer to the goal of a successful HIV vaccine. In 2009, a primeboost vaccine demonstrated an efficacy of 31.2%. This trial, RV144, signaled hope for the future and served as proof of concept that an effective HIV-1 vaccine is possible. Understanding the unique obstacles in HIV vaccine development has been key in creating breakthroughs and tracing a path forward. The complexity of this challenge has required innovative approaches to vaccine development. Future HIV preventive vaccine candidates may target multiple immune pathways. Strategies such as cytotoxic vaccines, envelope targets and antibodies such as broadly neutralizing antibodies or monoclonal antibodies may work in concert to achieve protection from HIV acquisition. An effective HIV preventive vaccine is ever near.