About the Research
The Collaboration for AIDS Vaccine Discovery includes two distinct types of programs:
- Vaccine Discovery Consortia are networks of research laboratories focused on scientific challenges involved in developing an HIV vaccine.
- Central Service Facilities are laboratories and facilities dedicated to improving methods of evaluating vaccine candidates and providing services to the vaccine discovery consortia.
Vaccine Discovery Consortia
The CAVD is focusing on providing funding and infrastructure for the translational research needed for moving a research finding into a vaccine candidate.
The CAVD has identified several of the most promising approaches, all of which are aimed at stimulating the body’s immune system to recognize and destroy HIV or HIV-infected cells. Vaccine candidates in development fall into two categories: vaccines that elicit neutralizing antibodies and vaccines that elicit cellular immunity. These two types of immune response work together in the body to fight off infection.
- Neutralizing antibodies: Classical neutralizing antibodies bind to virus particles and destroy them, preventing infection, but recent research suggests that antibodies may have other protective functions that also need to be explored. Six consortia are focused on designing vaccine candidates capable of eliciting protective antibodies against HIV.
Neutralizing antibodies form the basis of successful vaccines against major viral illnesses such as polio and hepatitis B. The HIV vaccine candidates tested in the late 1990’s and early 2000’s attempted to elicit antibodies capable of neutralizing HIV.
To date, HIV has managed to elude inactivation by antibody-inducing vaccine candidates. In part this is because HIV mutates rapidly, and the antibodies against the HIV strain used to make the vaccine are incapable of recognizing the mutated versions of the virus.
Additionally HIV may incorporate the body’s own sugar components into its outer coating and evade antibodies by masquerading as self. The CAVD is funding research into how HIV evades antibodies, and how to surmount existing challenges to design novel vaccines that can elicit broadly neutralizing and protective antibodies.
- Cellular immunity: Cellular immune responses kill off cells that have already been infected, stopping HIV from colonizing cells and causing disease. Five consortia will focus on improving upon vaccine candidates designed to elicit effective cellular immunity.
Cellular immune responses can eradicate viral infections by destroying the cells that become infected with HIV. Vaccines that elicit cellular immune responses are in various stages of testing.
These vaccines consist of HIV viral genes carried into cells via viral vectors or by direct injections of DNA. When the genes are taken up and expressed in the cells, the body’s cellular immune response is activated and killer T cells kill the infected cells.
Memory cells remember how to activate the killer T-cell response should HIV be encountered later in life.
- In addition to these initiatives, three VDCs focus on aspects of immunology that are relevant to both cellular and antibody-mediated protection. These programs include research into why some individuals have innate abilities to live with HIV infection without the need for antiviral therapy, the role of innate mucosal immunity in protecting against HIV infection, and the improvement of adjuvants that may improve the efficacy of vaccine candidates.
Central Service Facilities
Central Service Facilities ensure that HIV vaccine research results are comparable and reproducible, and that laboratory specimens can be stored for future study.
The use of consistent reagents and laboratory techniques will ensure that results generated by the Vaccine Discovery Consortia may be combined or compared for analysis.
Uniform and standardized methods of data analysis will further enhance the ability to make valid conclusions about a vaccine candidate.
The storage of research samples, such as blood samples collected from individuals enrolled in vaccine trials, will allow researchers access to specimens for further research.
The Central Service Facilities include two centers for standardization and development of laboratory assays, a mouse immunology laboratory to test new vaccine candidates in animals, a cryorepository for storage and distribution of specimens and reagents, and a data analysis and statistical center. Each Central Service Facility also conducts research to improve existing methods of analyzing vaccine research results and storing specimens.