Non-Human Primate Studies Reveal
PromisingVaccine Approach for HIV
Port St. Lucie, Fla. (May 11, 2011) – Research conducted at Oregon Health & Science University's (OHSU) Vaccine and Gene Therapy Institute (VGTI) has produced a potential vaccine against Human Immunodeficiency Virus (HIV). Details of this vaccine advance are published in the current online edition of the journal Nature, and the full study will be published in an upcoming print edition.
The research team, led by Louis Picker, M.D., associate director of the OHSU VGTI and director of the VGTI’s vaccine program, produced a unique vaccine that programs the immune system to respond more swiftly to the presence of HIV than it normally would.
The VGTI researchers tested their vaccine in rhesus macaque monkeys, using a primate form of HIV called Simian Immunodeficiency Virus (SIV). Just over half the monkeys infected with a highly aggressive form of SIV and given the new vaccine completely controlled replication of the virus, to the extent that even the most sensitive tests could not detect signs of SIV.
To date the vast majority of these monkeys have maintained control over the virus for more than a year. This group is in the same physical condition as normal healthy rhesus macaques, gradually losing any signs they had ever been infected. In contrast the macaques in the unvaccinated control group developed the primate form of AIDS.
VGTI says that their work suggests that the immune responses elicited by this new vaccine might completely clear SIV from animals that were initially infected - a first for a vaccine against AIDS-causing viruses. Anti-AIDS drug therapy is able to control the disease, but cannot clear the virus from its hiding place within the immune system’s own cells.
The VGTI team has been working for over 10 years on this vaccine, which is unique in using another virus, Cytomegalovirus (CMV) as the transport system. Once an individual is infected with CMV, the virus remains in the body for life. Dr. Picker and his team hypothesized that if such a persistent virus were used as a vector it could create and maintain resistance against HIV by programming a portion of the body’s immune system called effector memory T-cells to be constantly on the alert for the virus. It is believed that most people are already infected with CMV, but for the majority the virus causes little or no symptoms.
"CMV can pose a significant risk to a small subset of the population with known health conditions," explained Dr. Picker "However, the persistent nature of CMV infection can also have its benefits. In this case, the virus is used to carry a vaccine into the body and ensure that it remains in place to defend against HIV over a long period of time.”
“The next step in vaccine development is to test the candidate in clinical trials in humans. For a human vaccine the CMV vector would be weakened sufficiently so that it does not cause illness even in that vulnerable subset of the population, but will still protect against HIV,” said Dr. Picker.
Jay Nelson, Ph.D., executive director and vice president of VGTI Florida located at the Tradition Center for Innovation in Port St. Lucie, participated in this research project. He and VGTI Florida’s scientific director, Rafick-Pierre Sékaly, will also be involved in humanizing this vaccine and implementing the safety features necessary for clinical studies.
“This is an exciting breakthrough in our fight against one of the most devastating pandemics ever recorded in human history,” said Dr. Nelson.
The National Institutes of Health (NIH) and the International AIDS Vaccine Initiative provided funding for this research.
About OHSU
Oregon Health & Science University is the state’s only health and research university, and only academic health center. As Portland's largest employer and the fourth largest in Oregon (excluding government), OHSU's size contributes to its ability to provide many services and community support activities not found anywhere else in the state. It serves more than 184,000 patients, and is a conduit for learning for more than 3,900 students and trainees. OHSU is the source of more than 200 community outreach programs that bring health and education services to each county in the state.
About VGTI Florida
VGTI Florida is a world-class research institute in Port St. Lucie, Fla. that focuses on studying the human immune system to prevent and treat chronic infectious diseases, cancer and ailments that disproportionately affect aging populations. The Institute’s researchers have contributed to significant advances in the development of vaccines and other therapeutics to fight diseases such as AIDS, melanoma, breast cancer, prostate cancer, yellow fever and dengue fever. VGTI Florida is an independent 501(c) 3 nonprofit organization that is related to the Vaccine and Gene Therapy Institute at Oregon Health & Science University in Beaverton, Ore.
The research team, led by Louis Picker, M.D., associate director of the OHSU VGTI and director of the VGTI’s vaccine program, produced a unique vaccine that programs the immune system to respond more swiftly to the presence of HIV than it normally would.
The VGTI researchers tested their vaccine in rhesus macaque monkeys, using a primate form of HIV called Simian Immunodeficiency Virus (SIV). Just over half the monkeys infected with a highly aggressive form of SIV and given the new vaccine completely controlled replication of the virus, to the extent that even the most sensitive tests could not detect signs of SIV.
To date the vast majority of these monkeys have maintained control over the virus for more than a year. This group is in the same physical condition as normal healthy rhesus macaques, gradually losing any signs they had ever been infected. In contrast the macaques in the unvaccinated control group developed the primate form of AIDS.
VGTI says that their work suggests that the immune responses elicited by this new vaccine might completely clear SIV from animals that were initially infected - a first for a vaccine against AIDS-causing viruses. Anti-AIDS drug therapy is able to control the disease, but cannot clear the virus from its hiding place within the immune system’s own cells.
The VGTI team has been working for over 10 years on this vaccine, which is unique in using another virus, Cytomegalovirus (CMV) as the transport system. Once an individual is infected with CMV, the virus remains in the body for life. Dr. Picker and his team hypothesized that if such a persistent virus were used as a vector it could create and maintain resistance against HIV by programming a portion of the body’s immune system called effector memory T-cells to be constantly on the alert for the virus. It is believed that most people are already infected with CMV, but for the majority the virus causes little or no symptoms.
"CMV can pose a significant risk to a small subset of the population with known health conditions," explained Dr. Picker "However, the persistent nature of CMV infection can also have its benefits. In this case, the virus is used to carry a vaccine into the body and ensure that it remains in place to defend against HIV over a long period of time.”
“The next step in vaccine development is to test the candidate in clinical trials in humans. For a human vaccine the CMV vector would be weakened sufficiently so that it does not cause illness even in that vulnerable subset of the population, but will still protect against HIV,” said Dr. Picker.
Jay Nelson, Ph.D., executive director and vice president of VGTI Florida located at the Tradition Center for Innovation in Port St. Lucie, participated in this research project. He and VGTI Florida’s scientific director, Rafick-Pierre Sékaly, will also be involved in humanizing this vaccine and implementing the safety features necessary for clinical studies.
“This is an exciting breakthrough in our fight against one of the most devastating pandemics ever recorded in human history,” said Dr. Nelson.
The National Institutes of Health (NIH) and the International AIDS Vaccine Initiative provided funding for this research.
About OHSU
Oregon Health & Science University is the state’s only health and research university, and only academic health center. As Portland's largest employer and the fourth largest in Oregon (excluding government), OHSU's size contributes to its ability to provide many services and community support activities not found anywhere else in the state. It serves more than 184,000 patients, and is a conduit for learning for more than 3,900 students and trainees. OHSU is the source of more than 200 community outreach programs that bring health and education services to each county in the state.
About VGTI Florida
VGTI Florida is a world-class research institute in Port St. Lucie, Fla. that focuses on studying the human immune system to prevent and treat chronic infectious diseases, cancer and ailments that disproportionately affect aging populations. The Institute’s researchers have contributed to significant advances in the development of vaccines and other therapeutics to fight diseases such as AIDS, melanoma, breast cancer, prostate cancer, yellow fever and dengue fever. VGTI Florida is an independent 501(c) 3 nonprofit organization that is related to the Vaccine and Gene Therapy Institute at Oregon Health & Science University in Beaverton, Ore.
