AIDS vaccine research is at a critical period
At 9:12 on December 5, 2008 Source: "Science Times"
The AIDS epidemic is the world's largest health crisis, and control of epidemic infectious disease vaccine is the most effective means of public health in the world, millions of people have benefited. However, the human immunodeficiency virus (HIV) vaccines are in development across the most horrible pathogens.
 
Recently, the Chinese Academy of Medical Sciences / Beijing Union Medical College, director of the Center for AIDS Research Professor Zhang Linqi, in an interview with reporters introduced the International AIDS Vaccine Initiative (IAVI) 2008 blueprint on AIDS vaccines.
 
In 2007, a popular candidate for the AIDS vaccine research and development work in the clinical trial stage of the failure of this industry to have a broad consensus: It is time to seriously assess the time, how can we best use the limited resources available?
 
Zhang Linqi said that the International AIDS Vaccine Initiative in 1998 described a two-year blueprint for AIDS vaccine to the world's attention to AIDS vaccine research and development. In 2008 the blueprint, IAVI in the area to put forward a challenge to rethink the positioning and AIDS vaccine research and development and look forward to the focus of attention.
 
Vaccine research and development and to rethink position
 
At present, researchers have found in the animal model of AIDS vaccine research and development of the feasibility of evidence, but the body needs to be confirmed.
 
"" Blueprint for AIDS vaccine in 2008, "the researchers recommended first task will be easier to reach into several parts, rather than directly toward the ultimate goal, and then say the least, can not directly toward the kind of candidate vaccines will be effective the human body Intermediate goal. And that should not be a lot of resources to the current line-test the validity of a large number of vaccine candidates, and they should be used to solve the key hindered the development of vaccines up scientific problems. "Zhang Linqi told reporters.
 
The other proposal, however, the R & D strategic areas: in addition to do more to find how to induce broad-spectrum HIV antibodies, to design vaccines to increase their lead to cell-mediated immune response is also one of the important strategy. This calls for efforts to explore the potential of more effective delivery of HIV Immune virus vector of the original, including the copy-carrier. Copy the development of the vector-control agencies will no doubt bring a new set of problems. At the same time, efforts also need to explore the AIDS vaccine should choose which HIV antigen (such as which segments of the HIV). But so far, there has been concern about how to deliver these antigens, while neglecting the needs of what kind of antigen.
 
R & D critical period facing a huge challenge

In the current AIDS vaccine research and development, researchers are facing several major challenges in science. If HIV is a retrovirus that can lead to immune protective effect of high variability and may lead to immune escape in order to become a goal of running target (that is, until the candidate vaccine design and testing after the virus may have been a serious variation).
 
Said Zhang Linqi, HIV immune escape mechanism is more subtle, HIV infection is precisely the immune system fight the infection of immune cells. The researchers have not yet established the ideal of HIV infection and acquired immunodeficiency syndrome (AIDS) animal model. And, HIV has infected a number of ways (genital, rectal, oral and intravenous) and forms (do not rely on cells and cells of the virus and related viruses), may need to be strong mucosal immune response in order to provide protection from sexually active The elderly to young people can be infected, so an effective vaccine should be able to provide sustained, long-term immune protection.
 
"Despite these challenges, the study shows that the AIDS vaccine can be achieved, it is at a critical period of development." Zhang Linqi said.
 
In the history of AIDS vaccine development has experienced a wave of twice. In the first wave of scientists to follow the success of the hepatitis B vaccine research and development path: to identify the virus and trigger a part of the antibody (called antigen), after purification can be made in the human body's immune antibodies similar to the cause of the original. After emerging evidence that this approach ineffective. The second wave of AIDS vaccine research and development began in 1995, was marked by the development of vaccines will be the focus shifted to the antibodies from the immune system in a different direction - cell-mediated immunity (CMI) area. At present, the clinical close to the 30 AIDS vaccine candidates are almost on the goal to stimulate the CMI response designed, researchers have reached a consensus - in this direction have been too far away.
 
Persist in the end is the only option
 
Scientists believe that, HIV antibody and the issue of restricting the development of AIDS vaccines bottlenecks. The second problem is that the immune cells to address HIV issues. This is a series of problems to be resolved: the establishment of such research in order to control HIV infection as the focus of the project and to ensure long-term funding. The projects main objective is to find T (CD4 + and CD8 +) cells is the role of HIV in the areas where infection control; to find live attenuated SIV infected with SIV control mechanism, the live attenuated SIV immunization of laboratory animals, Exposed to the vaccine with the same (homologous) SIV strain after the viral load can continue to reduce the thousands of times. This is the only way to achieve this ideal than the effect of the vaccine. Taking into account the attenuated strain of pathogenic strain back to the possibility of preparation of live attenuated AIDS vaccine is not critical thinking.
 
The blueprint proposes AIDS vaccine research and development and to explore a sufficient number of contributions to non-human primates, so that large-scale trial to be conducted, and reached statistical significance. These pilot projects aim to find out the live attenuated SIV to protect non-human primates infected with SIV from the mechanism.
 
In the AIDS vaccine development and the rational use of vector vaccine can be optimized, and copy out-Carrier and non-replicating vector between the priorities is very critical. Also good candidates for the vaccine to carry out small-scale test of the effectiveness with a view to achieve the target. Previous studies have shown that, γ interferon ELISPOT tests can not accurately predict the effectiveness of the vaccine.
 
Of course, to cut R & D pipeline in the low-quality vaccine candidates can focus on its more promising way up, or to solve scientific problems in a number of key issues. It is imperative that the global clinical trials should be covered by a series of scientific hypothesis and the final will represent the hypothesis that these vaccine candidates include: to trigger a response to broad-spectrum HIV antibodies and vaccines; mucosal immunity induced by the vaccine; cover optimization The number of HIV antigen vaccine, and so on.
 
Zhang Linqi said that the development of a vaccine usually takes several years and sometimes decades. At present, most of the approved production of its vaccine research and development will take at least several decades; the world is still waiting for the birth of a new vaccine. Although the AIDS vaccine research and development in the area of the front is full of challenges and uncertainties, but the researchers are convinced that persist in the end is the only option.