SCIENTISTS from The Scripps Research Institute (TSRI) and the La Jolla Institute for Allergy and Immunology (LJI) may have found the best delivery mode for a vaccine against HIV.
A publication in ContagionLive said the results of their new study show that "optimizing the mode and timing of vaccine delivery is crucial to inducing a protective immune response in a practical model," a press release on the study stated. For their study, published in the journal, Immunity, the scientists found that, "administering the vaccine candidate subcutaneously and increasing the time intervals between immunizations improved the efficacy of the experimental vaccine and reliably induced neutralizing antibodies." These antibodies are key in promoting an effective immune response as they inactivate an invading virus before it is able to set up shop in the body.
"These neutralizing antibodies have been notoriously difficult to generate for HIV," the statement stated. The scientists utilized outbred Indian Rhesus Macaques (Macaca mulatta) for the study subjects.
The macaques were, "immunized at three time points: week 0, week 8, and week 24. All immunizations were administered as split doses.
To produce a reliable neutralizing antibody response, multiple variations of the trimers and immunization protocols were used to discover the best strategy. Because the scientists had observed in previous studies that, "follicular helper T cells help direct the maturation steps of antibody-producing B cells," they administered "the vaccine subcutaneously versus the more conventional intramuscular route, spacing the injection at eight weeks instead of the more common 4-6 weeks.
Speaking on the findings, Professor Dennis R. Burton,who is also scientific director of the International AIDS Vaccine Initiative (IAVI) Neutralizing Antibody Center and of the National Institutes of Health's Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID) at TSRI said the study is an important staging point on the long journey toward an HIV vaccine. "The vaccine candidates we worked with here are probably the most promising prototypes out there, and one will go into people in 2018."