Team of researchers from The Scripps Research Institute, International AIDS Vaccine Initiative and The Rockefeller University have successfully shown that an experimental vaccine candidate can stimulate the immune system activity necessary to stop HIV infection. This research is extremely significant. In fact, scientists believe that findings of the study could provide key information for the development of an effective AIDS vaccine.
Efforts to create effective vaccine against HIV so far have been virtually fruitless. However, scientists already describe results of this latest research as spectacular. The long-term goal of the research is to develop a vaccine that prompts the body to produce antibodies that bind to HIV and prevent infection and current experiments with mice models showed promising results.
Many vaccines for other diseases use a dead or inactive version of the disease-causing microbe itself to trigger antibody production. However, this simple approach does not work with HIV – immunizations with “native” HIV proteins are ineffective in triggering an effective immune response, due to HIV’s ability to evade detection from the immune system and mutate rapidly into new strains. This makes HIV vaccine a particularly challenging task for scientists, which explains why science still has not produced an effective one.
This challenge did not make scientists believe that AIDS vaccine is impossible. Instead they figured out that it has to consist of a series of related, but slightly different proteins, called immunogens, to train the body to produce broadly neutralizing antibodies against HIV. It is a completely different approach than a traditional, so called “booster” shot, where a person is exposed to the same immunogen multiple times, until develops imunity to a certain disease.
The research required a broad partnership between different institutions. During it scientists tested a protein nanoparticle designed to bind and activate B cells needed to fight HIV. This protein is an immunogen called eOD-GT8 60mer. This compound had to be tested, so another lab using genetic engineering created a mouse model to produce antibodies that resemble human antibodies.
The experiments showed that immunization with the compound produced antibody “precursors” with some of the traits necessary to recognize and block HIV infection. This suggests that eOD-GT8 60mer immunogen could be a good candidate to serve as the first in a series of immunizations against HIV. Professor David Nemazee evaluated results like that – “The vaccine appears to work well in our mouse model to ‘prime’ the antibody response”. In another research scientists used the same immunogen in a slightly different mouse model, which showed promising results as well.
As scientists have taken approach to collect a variety of different immunogens to develop a united HIV vaccine, now they have to find other needed immunogens. For further testing mouse models will have to be developed, which means that collaboration between different disciplines and laboratories will remain crucial on the path to the ultimate goal. HIV vaccine would be a major breakthrough at fight against AIDS, as it still is arguably the biggest threat to human population. As previous attempts to prevent the spread of the disease proved ineffective and there is no cure for it, vaccine could be one of the greatest scientific achievements of the century.