Phase I of HIV vaccine trial begins
This month Phase I of a clinical trial begins to test the safety of vaccine that can prevent HIV infection, according to a press release from the University of Massachusetts Medical School. The trial will take place on four different sites in the United States. During the research, the ability of the vaccine to mount an immune response against HIV will also be monitored.
Dr. Shan Lu, professor of medicine, biochemistry and molecular pharmacology, is working on the research and development of DNA vaccines at the University of Massachusetts Medical School. DNA vaccines use synthetic DNA to create immune responses to HIV after vaccination. One group of participants in the study will consistently introduce a DNA vaccine, and then a protein vaccine, which corresponds to proteins obtained from DNA. To strengthen the immune response, the protein vaccine will still be combined with the adjuvant GLA-SE.
Another group of participants will receive DNA and protein vaccines together, and not consistently as in the first group. The approach to using both DNA and protein vaccines, whether sequentially or together, activates both the antibody and cellular immune responses, both of which may be required for effective vaccination against HIV.
"We’ve made significant progress in developing a cocktail of antigens capable of producing antibodies using our prime-boost method," said professor Lu. It is believed that vaccination by the prime-boost method is crucial for initiating an immune response to HIV, which can last for years.
Lu believes that this type of vaccination strategy, involving a mixture of proteins derived from different viral subtypes of HIV, most likely stimulates broad immune responses, offering the best hope for an HIV vaccine. The vaccines used in the study include five DNA components and four proteins to stimulate powerful and broad immune responses.
The vaccine will be tested in healthy volunteers for safety and tolerability, as well as for the immune response of vaccines for six to twelve months. The trial will be double-blinded - neither researchers nor study volunteers will know who gets the vaccines, and who recives the placebo, until the investigation is completed. The study will include volunteers who are assessed with a low risk of contracting HIV. They will also receive ongoing support and advice on HIV prevention.
Historically, vaccines have been extremely successful in preventing the development of infectious diseases such as smallpox, poliomyelitis, measles and yellow fever. By presenting foreign antigens to the immune system in healthy people, vaccines can stimulate the production of antibodies and cells that are ready to fight the pathogen before infection strikes. Similarly, HIV vaccines represent the best long-term hope of ending the HIV pandemic.