In a new study that was published in the journal Proceedings of the National Academy of Sciences, a Thailand based international research team headed by the Duke Human Vaccine Institute showcased newly observed interactions between antibodies that often work to block HIV vaccines.
The trial, referred to as RV 144, investigated two trial vaccines that when combined, demonstrated an astounding thirty-one percent protection rate across all participants. Despite this reassuring number, the rate sadly just fell under the minimum requirements for mass public use, Even so, more analysis of the data collected in the trial are yielding an enormous hoard of data regarding the virus itself and new potential vulnerabilities.
The analysis, led by Dr. Georgia D. Tomaras, investigated the relationship that sheds light on why the vaccine studied in RV144 failed to successfully protect more of the study participants.
"We learned that a specific vaccine-induced immunoglobulin A can weaken the protective effect of immunoglobulin G. IgA competes with IgG to bind to the same site on the virus's outer envelope that is exposed on infected cells," Tomaras commented. "In work with my colleague here at Duke, Dr. Guido Ferrari, we found that the IgA antibodies can block the activity of natural killer cells activated by IgG, further interfering with the vaccine-induced immune response."
Dr. Tomaras suggested that the less effective treatment correlated with participants who had more immunoglobulin A compared to G, proposing that the ratio of virus-specific immunoglobulin A to immunoglobulin G in a patients blood could be a very important indicator for the potential effectiveness of a vaccine.
"Understanding that certain vaccine-induced immunoglobulin A antibodies in the blood may interfere with an antiviral function of another antibody is a new finding that can lead to further vaccine development on how to induce effective antibody responses," commented Tomaras.
Prevention, medication and utilization of HIV/AIDS support groups are the best ways to protect yourself from and manage HIV.