Antibody Discoveries Latest Advance in AIDS Vaccine Research Renaissance
07/17/2010
Is a vaccine within reach?
The author looks over test results at IAVI's AIDS Vaccine Design and Development Laboratory in Brooklyn, NY, on May 21, 2010. Photo by Chris Hondros/Getty Images North America
The world's scientists have had quite a foe in the wily virus known as HIV, but new discoveries from last fall and last week show we might just be starting to get an upper hand in the battle. As we head to the 2010 International AIDS Conference in Vienna, with the virus still wreaking havoc around the world, this is welcome news - and reason we must be more determined, forward-thinking and collaborative than ever in creating a tool to help end this devastating pandemic.
Last week, two teams of scientists at the U.S. National Institutes of Health (NIH) published papers in the journal Science announcing they have identified two closely related antibodies, called VRC01 and VRC02, that potently neutralize a broad range of HIV variants from infecting human cells in the laboratory. They also solved the molecular structure of one of these broadly neutralizing antibodies and explained how it accomplishes this feat. I was part of another group of scientists to report in the same journal last fall that we had isolated another pair of antibodies, called PG9 and PG16, with potency and breadth similar to that of the VRC antibodies.
These discoveries are important for two reasons:
1. The antibodies identified are all very potent neutralizers of HIV, meaning that very small amounts of them are required to block the entry of the virus into the cells it targets. This suggests that similar antibodies generated by active immunization would not have to be produced in large quantities to confer protection from HIV. That matters because eliciting neutralizing antibodies in large amounts through active immunization has proved challenging.
2. The different spots on the surface of the virus to which these antibodies attach - the CD4 receptor binding site for the VRC antibodies and an accessible site on top of the HIV's viral spike for the PG antibodies - appear to change less often than other areas of the virus, which is critical because HIV is extremely mutable. Understanding these spots at a molecular level will help researchers design better HIV vaccine candidates to generate similar antibodies.
The identification of these antibodies alone does not produce a vaccine. There are many steps ahead before we will have viable vaccine candidates, based on these findings, that can be tested in clinical trials. However, the news has added to a growing, if cautious, sense of optimism among scientists involved in AIDS vaccine design and development.
Before these discoveries, researchers had not identified any new broadly neutralizing antibodies in more than a decade, prompting the organization I work for, the International AIDS Vaccine Initiative, to launch a worldwide effort in 2006 to find them. Many of us in the field now believe that after many years of disappointment, we have finally reached something of a tipping point in the quest to develop an effective HIV vaccine. Aside from the antibody discoveries, a clinical trial completed in Thailand last year provided the first demonstration of protection - albeit modest protection - against HIV infection in humans through immunization.
More hard work and ingenuity will be needed if we are to deliver a broadly effective preventive AIDS vaccine. Researchers involved in AIDS vaccine design generally agree about the biggest problems impeding development. Vaccine candidates must be devised to both elicit broadly neutralizing antibodies, and to more effectively engage other dimensions of the immune response, such as cell-mediated immunity and the innate immune response.
IAVI's worldwide network, including partners across many sectors and continents, is deeply engaged in addressing each of these challenges. We are also working collaboratively with groups like the NIH to accomplish the common goal of an effective HIV vaccine. We are in the early stages of exploiting the recent antibody discoveries. But to translate this scientific promise into the reality of an effective AIDS vaccine, we need the continued support of the policymakers, donors, advocates, trial participants and health professionals gathered in Vienna and all over the world.
Dr. Sanjay Phogat is principal scientist at the International AIDS Vaccine Initiative (IAVI).
GREAT WORKS BY GREAT MEN! PLEASE KEEP UP THE GOOD WORKS. WE ARE GETTING CLOSER ON A DAILY BASIS. WE SHALL BE THERE!
— Oyedeji Taiwo Michael on 2010-07-21
Thank you for the kind words Oyedeji. We share your optimism and enthusiasm!
— Dr. Sanjay Phogat on 2010-07-21
This is wonderful to hear and I encourage all those currently working on this to continue to take courage, think outside the box, revisit discarded ideas, collaborate and above all else keep going!
— Joy Spencer on 2010-07-22
This is a tremendous scientific break through that gives hope and life to man kind.Let those hard working minds keep going and the donors and policy makers also increase their effort to sustain this endevour.
— Kayonde Peter on 2010-07-24
Thanks for the comments Joy and Kayonde. Much appreciated.
— Dr. Sanjay Phogat on 2010-07-28
Its great to read the tremendoues efforts these great researchers are doing in bringing hope to the world. Pray God guide your team through to the successful accomplishment of the desired goal.
— nchinda Thaddeus on 2010-08-04
34 million hiv infected people are curiously waiting the sucessful aids vaccine . IAVI team is doing very much . world’s hope is depend on theirs research . may god bless them all these researchers .
— hidden helper on 2011-10-24