Why Is It So Hard to Find a Vaccine for AIDS?
The AIDS vaccine, or HIV vaccine, prevents AIDS for a period of time after injection (similar to the principle of a hepatitis B vaccine). The HIV vaccine is considered the most effective tool for preventing AIDS. HIV (HIV) is a retrovirus and reverse transcriptase lacks a corrective repair function, so HIV mutates very frequently.
- Chinese name
- AIDS vaccine
- Specific
- HIV vaccine
- Function
- Preventing AIDS for a period of time
- Raw materials
- Microbes or their toxins, enzymes, etc.
- vaccine
- HIV inactivated vaccine and live attenuated HIV vaccine
- The AIDS vaccine, or HIV vaccine, prevents AIDS for a period of time after injection (similar to the principle of a hepatitis B vaccine). The HIV vaccine is considered the most effective tool for preventing AIDS. HIV (AIDS virus) is a retrovirus and reverse transcriptase lacks a corrective repair function, so the mutation frequency of HIV is very high.
- Until the 21st century, there were no specific treatments for HIV. Drugs used to treat HIV infection can only control the replication of the virus and cannot completely eliminate the virus. Therefore, the development of a safe and effective vaccine is one of the important means of controlling HIV transmission. HIV susceptible persons receive an AIDS vaccine to develop an immune response, thereby generating specific resistance to the disease, improving immune levels, and achieving the purpose of preventing and treating HIV.
AIDS vaccine vaccine
- A vaccine is a biological product, which refers to a preparation for prevention, diagnosis, and treatment prepared with microorganisms or their toxins, enzymes, human or animal serum, cells and the like. HIV vaccines include HIV inactivated vaccines, live attenuated HIV vaccines, subunit vaccines, live vector virus protein vaccines, and DNA vaccines.
- Inactivated and attenuated live vaccines
- HIV inactivated vaccine and live attenuated HIV vaccine
- In the prevention of many infectious diseases, inactivated vaccines or
- Subunit vaccine
- A subunit vaccine is a recombinant viral membrane protein monomer or polypeptide. It is composed of one or more non-infectious particles of HIV protein and has a packaged retroviral nucleic acid sequence, so it has good safety. Recombinant gp120 protein vaccine developed by American Vax Gen is the only HIV-1 vaccine that has entered human phase III clinical trials. However, because the vaccine is a monomeric recombinant protein, the neutralizing antibody spectrum produced by the stimulus is narrow, and the anti-HIV-1 wild strain has limited attack power. Therefore, in order to improve the protective ability of this type of vaccine, it is necessary to continue to develop recombinant glycoproteins close to natural HIV-1 and further understand the membrane protein structure and immune invasion mechanism.
- Live vector virus protein vaccine
- Genes encoding viral proteins are inserted into the genome of other live viruses or cells and used to infect animals or humans, so that foreign genes are expressed in host cells, which can generate immune responses to gene products and vectors. Live virus vectors include vaccinia virus, baculovirus, and adenovirus. The most studied is the pox virus vaccine. Pox virus vaccines replicate in the cytoplasm of infected host cells and are non-carcinogenic. Such vaccines can induce cellular and humoral immunity in the body and the vaccine is easy to produce and preserve. However, attention should still be paid to its safety. HIV infection causes immune suppression in the body. If the carrier mutates in the body, it threatens the patient's own life. Canarypox virus vector vaccines that have been reported to enter phase II clinical trials have been shown to produce durable humoral and cellular immune responses. Because avian pox virus does not have a complete replication cycle in human cells, its safety is relatively good.
- DNA vaccine
- The DNA vaccine is called the third generation vaccine after the complete pathogen vaccine and genetically engineered recombinant protein vaccine. The plasmid DNA into which the target antigen gene is inserted and expressed is transferred into the body cells through various transfer pathways. The expression is processed and synthesized by the host cell. molecule. In 1992, Tang et al. First directly inoculated plasmid DNA encoding foreign proteins through mouse skin, and found that this type of immunization can also cause the body to produce antibody responses, confirming that "naked" DNA can be used as an immunogen through antigen expression. After the naked plasmid DNA is injected into the body, it can enter cells and continue to express foreign proteins, thereby effectively stimulating humoral and cellular immunity. Their effectiveness in cynomolgus monkey trials has been proven and can usually prevent AIDS caused by SIV. Through this direct in vivo injection method, the antigenic epitope of the protein for immunization is generated in a way that can be naturally recognized by the host receptor. The presentation of the antigenic peptide is similar to that of natural infection. This characteristic causes the conformational epitope Protective immunity is particularly important. This vaccine combines the effectiveness of a live attenuated vaccine and the safety of a subunit vaccine. It not only can continuously express antigenic proteins like a live virion, but also can conveniently select the required gene fragments to stimulate the ideal immunity. Answer. Because this vaccine can express antigens in the body cells and has good immunogenicity, it can induce a humoral immune response and a strong cytotoxic response. At the same time, it can be made into a multivalent vaccine, which can be easily modified to adapt to epidemic viruses. It is easy to prepare and preserve, and is especially suitable for developing countries. Based on the above advantages, DNA vaccines are hotspots in the development of AIDS vaccines today, and DNA vaccines for HIV have entered human trials.
Significance of AIDS vaccine research
AIDS vaccine AIDS
Current HIV vaccine treatment levels
- The HIV / AIDS epidemic has had a significant negative impact on society and the economy. Until the 21st century, there were no specific treatments for HIV. Although highly active antiretroviral therapy (HAART) has achieved certain results in reducing patient suffering and extending patient life, it is used for treatment. HIV-infected drugs can only control virus replication and cannot completely eliminate the virus. Anti-HIV drugs are expensive, have serious side effects, and improper use of drugs can also induce the generation of resistant strains. Therefore, the development of a safe and effective vaccine is one of the important means of controlling HIV transmission. HIV susceptible persons receive an AIDS vaccine to develop an immune response, thereby generating specific resistance to the disease, improving immune levels, and achieving the purpose of preventing and treating HIV.
AIDS vaccine vaccine effect
- The role of most classic vaccines is to prevent pathogenic infections from developing into disease, not to prevent pathogens from entering, but HIV is different. Because even a small amount of infections can cause AIDS, the vaccine is required to produce high-value neutralizing antibodies and Effective memory to clear all incoming viruses. The following phenomena show that the AIDS vaccine is feasible. First, HIV strains are mostly monotypes, which provides opportunities for vaccine-induced immune responses. In addition, the virus has a restricted structure and genetic characteristics, which can further improve the recognition mechanism that protects immunity. High-exposure, uninfected, and long-term, progression-free immune responses show the viability of HIV vaccines. Examples of passive protection of lentiviral infection in non-human primate models also prove that HIV vaccines are feasible.
HIV AIDS vaccine HIV infection
- So far, global HIV infection and AIDS have become increasingly serious, and the development of anti-HIV vaccines has received increasing attention and has made some promising progress. The more realistic goal in the development of HIV vaccines today is to prepare vaccines that can reduce their level of infection at the initial infection and effectively control the level of virus replication in the future to slow the clinical course. With the in-depth study of HIV, the completion of basic work such as the epidemic characteristics of HIV, the cloning, sequencing and reassortment of epidemic strains, as well as the clarification of the biological characteristics of the HIV virus, especially the genetic variation, new and more innovative An effective vaccine ultimately realizes the desire to prevent and treat AIDS.
AIDS vaccine vaccine fate
- Fateful HIV vaccine
- Originally, the vaccine AIDSVax, developed by VaxGen, was a recombinant HIV outer membrane glycoprotein gp120, although hepatitis B was used.
- A successful vaccine should be able to induce both broad-spectrum neutralizing antibodies and cytotoxic T lymphocytes. Due to the great difficulties of the former, several vaccines under development induce cytotoxic T lymphocytes. It has been found in non-human primate models that although this type of vaccine cannot prevent infection, it can control the level of the virus, reduce the destruction of CD4 + T cells in the lymphoid tissues associated with the gastrointestinal tract in the early stage, and delay the progress of the disease. In addition, if humans are vaccinated before HIV exposure, it may be possible to reduce the level of infection because the vaccine can reduce the level of the virus and the risk of second-generation transmission may also be reduced. However, there are several points that must be noted.
- First, whether the "T cell vaccine" has any effect on human HIV has not yet been proven. So far, only one T-cell vaccine has been tested in humans: the MRKAd5HIV-1 (gag, pol, nef) trivalent vaccine from Merck. Two clinical studies were conducted. The first was the STEP study (Clinical Trial Registration Number: NCT00095576), which was conducted in North America, South America, the Caribbean, and Australia; the second was the Phambili Study (NCT00413725), which was conducted in South Africa. . Since the data from the STEP study showed that the trivalent vaccine could not prevent HIV infection, nor could it reduce the virus levels of vaccinated volunteers after HIV infection, both studies had to be terminated early. Unexpectedly, a factorial analysis of the data in the STEP study also found that new HIV infections were even higher among vaccinated people than in the placebo group. Among the vaccinators, the relative risk of HIV infection was highest in men who had not been circumcised at the time of enrollment, and who had congenitally acquired the viral vector, adenovirus 5 neutralizing antibody. Those who produced adenovirus 5 neutralizing antibodies did not have a significant increase in the risk of HIV infection.
- In addition, the immune response of T-cell vaccines varies from person to person and may be significantly associated with HLA haplotypes. Therefore, T-cell vaccines may enhance the body's natural immune response to HIV, depending on the individual's HIV haplotype. In other words, such vaccines are only effective for individuals with "favorable" HLA haplotypes.
- Third, traditional virus vaccines, such as polio, smallpox, and measles, can protect vaccinators against infection, completely eliminate the virus, and the protection can be sustained. Extensive vaccination in the population can reduce the number of infected people and the spread of infection. Even when vaccinated only in susceptible populations, the spread of infection can be greatly reduced. This is the herd protection effect of vaccines. However, HIV T-cell vaccines cannot prevent infection, and can only delay the progression of the disease by reducing the level of the virus. Although the risk of second-generation transmission will be reduced, it will not be blocked. And virus replication still exists at a certain level, and HIV will inevitably mutate, which will eventually escape immune control and increase the risk of second-generation transmission. Therefore, the population protection effect of any T cell vaccine is transient.
- The failure of the first T-cell vaccine to control the risk of infection or the level of the virus forced the development of HIV vaccines to relocate.
- There is little hope for successful development
- March 03, 2008 According to the BBC, the development of an HIV vaccine has been 20 years old. Although scientists have worked hard for this, the vaccine that the world desires has been reluctant to play. . Some scientists even say that the hope of a successful vaccine development is "very slim." Among all the scientists involved in vaccine development, Professor David Baltimore, president of the American Association for the Advancement of Science, played a leading role. Baltimore passed a frustrating message to people in an interview with the media. He said that although he has been working hard, the hope of successful development is "very slim." "In 1984, we were told that, since the virus has been found, the vaccine against it must be hiding in the corner. However, compared to when we found the virus, we barely moved forward. . "
- Ongoing vaccine development
- Why the human body cannot produce a broad spectrum of neutralizing antibodies during natural infections. If this question can be answered, it will help develop an effective vaccine and induce the production of corresponding antibodies. Moreover, the immune response induced by the vaccine must be more potent than the immune response induced by natural infection. Monoclonal antibodies also have the function of broad-spectrum neutralizing antibodies. Although very few, which have not been available until the 21st century, the approach of inducing monoclonal antibodies may be effective in developing HIV vaccines. In addition, the researchers discovered by X-ray crystallization technology how HIV uses the CD4 receptor to enter cells, and how a broad-spectrum neutralizing antibody binds to the CD4 binding site to effectively neutralize HIV. This finding will help For HIV vaccine development.
- Studying the trimer structure of HIV envelope protein is a research hotspot in the 21st century, and some new research ideas are expected. Another idea is to design a new envelope antigen, that is, to add a scaffold protein to the envelope protein of HIV, so as to ensure that HIV can be recognized by the immune system and produce antibodies.
- A vaccine developed by inducing broad-spectrum reactive cytotoxic T lymphocytes and neutralizing antibodies will not be useful, unless the effects of this vaccine can be used within a very short time window before the virus can lie down It's gone. A deeper understanding of the early mechanisms of HIV infection will help clarify the role of innate immune responses and mucosal immune responses in controlling HIV infection, and how to regulate these effects to broaden the time window for virus eradication and prevent HIV Enter the lymphatic tissue of the gastrointestinal tract.
- People may not be able to develop traditionally successful HIV vaccines because there are many scientific problems to be solved. To solve these obstacles and problems, scientists must return to basic research and carry out more in-depth research that has not been explored in vaccine development by the 21st century. For the development of HIV vaccines, a cautiously optimistic attitude must be maintained, and a large amount of basic research must be carried out.
AIDS Vaccine Domestic Research Organization
- China AIDS Vaccine Alliance
- In March 2009, the China AIDS Vaccine Alliance (CAVI) was formally established at the first China AIDS Vaccine Forum held in Beijing. The alliance is spontaneously formed by dozens of R & D units engaged in AIDS vaccine research in China, and is the first AIDS vaccine research organization in China.
- At the subsequent regional consultation meeting on AIDS vaccines in Asia, Shao Yiming, one of the founders of CAVI and chief expert of AIDS at the Chinese Center for Disease Control and Prevention, introduced to the Science Times reporter: "The development of an AIDS vaccine is a difficult and systematic project. We can't just rely on individual research teams to solve in a short period of time. If we want to make a difference, we must strengthen cooperation. CAVI is the best platform for Chinese vaccine research teams to unite under the banner of major national science and technology projects to carry out collaborative research and participate in international cooperation. "
- Asian AIDS Vaccine Regional Association
- The Asian AIDS Vaccine Regional Consultative Conference was jointly organized by the World Health Organization, UNAIDS, the Global AIDS Vaccine Enterprise Program, the National Institutes of Health's AIDS Research Office, and the China Centers for Disease Control and Prevention. Zeng Yi, an academician of the Chinese Academy of Sciences, introduced to the reporter of "Science Times" that there are various AIDS research organizations in developed countries and global organizations. He believes that the establishment of CAVI can not only help scientists in the United Nations, but also help strengthen international exchanges.
- Series of questions
- Although China's AIDS vaccine research has a certain strength, there are also a series of problems, such as less innovative research, more repeated research, more single team research, less collaborative research, upstream R & D and downstream development, etc. Joint team. CAVI was established to respond to these situations. According to reports, CAVI has combined the four research groups and two research platforms supported by the major scientific and technological projects of the "11th Five-Year Plan", which basically covers the main researchers in the development of AIDS vaccines in China. Wang Youchun, director of the Cell Division of the China National Institute for the Control of Pharmaceuticals and Biological Products, introduced to the "Science Times" reporter that the purpose of the alliance was to determine the development direction of AIDS vaccine development in China in the future, integrate resources, reduce repetitive work, and conduct innovative research. He said that the alliance will also establish objective and unified evaluation methods, management methods and sharing mechanisms to ensure better results in national funding.
AIDS vaccine clinical trials
- The preventive AIDS vaccine approved for phase II clinical trials was started by researchers in Jilin University, Changchun Pak Pharmaceutical Co., Ltd., China Pharmaceutical and Biological Products Testing Institute, and the Center for Disease Control and Prevention of Guangxi Zhuang Autonomous Region. Research. The first phase of the clinical trial began in Guangxi on March 12, 2005. A total of 49 volunteers received the vaccine. Phase II clinical trials are still underway in Guangxi, and 230 volunteers will conduct a series of experimental studies with informed consent and protection of the legitimate rights and interests of the subjects.
- Yan Jiangying, a spokesperson for the State Food and Drug Administration of China, said that the first phase of the clinical trial was to explore the safety of the AIDS vaccine in healthy people. The results of the first-phase experiment showed that in a small range of healthy people, the vaccine developed by China is safe. The second-phase clinical trial is mainly to further explore its safety in high-risk healthy populations, and at the same time, to initially explore its effectiveness.
- Yan Jiangying emphasized that the research on AIDS vaccine is a long-term process, and it has not been able to show that we have a successful vaccine until the 21st century. "When it can be applied to patients, there is still a long way to go." The results of this human experiment consider whether to enter a phase III clinical trial, which is mainly to evaluate the effectiveness of the vaccine in a larger population.
- On March 2, 2011, Changchun High-tech announced that the therapeutic AIDS vaccine project declared by the company's subsidiary pharmaceutical company Changchun Baike Pharmaceutical Co., Ltd. had officially received the "drug clinical trial approval" issued by the State Food and Drug Administration. , Approved for Phase I Clinical Trial
AIDS vaccine updates
? The dawn of AIDS vaccine research?
- Clare Thomas's pessimistic judgment on the prospects for the AIDS vaccine appears to be challenging. The senior editor of the journal Nature-Medicine, after interviewing 25 authoritative AIDS experts, concluded that "an effective vaccine for AIDS does not seem to be discovered in the next 10 to 15 years", a view published in 2009.8 In the journal Nature-Med.
- Challenging this view comes from new developments in a new AIDS vaccine clinical trial being conducted in Thailand. On September 24, U.S. and Thai researchers jointly announced in Bangkok, Thailand, that a new experimental vaccine can reduce the risk of HIV infection in humans by 31.2%. This is the result of more than 16,000 volunteers selected by researchers in Thailand after 6 years of testing.
- Like a spark of sparks in the dark, this result is exciting for AIDS researchers worldwide. The Associated Press reports that this is the first vaccine in the world to be confirmed to have a certain immune effect, which makes people re-see hope for future AIDS vaccine research.
- But can this spark burn into a torch leading the HIV vaccine out of the dark?
- On the same day, the World Health Organization and UNAIDS issued a joint statement, while affirming the "significance" of the test results, calmly stated that "based on the current test results, the production of this vaccine cannot be approved." The road to combating AIDS remains long.
- The project, called RV144, was implemented in 2003 by the U.S. military and the Thai Ministry of Public Health. After the failure of Merck's global AIDS vaccine human trial in September 2007, the project became the only large-scale AIDS vaccine clinical trial in the world involving more than 10,000 people.
- The trial's research strategy builds on two previous failed HIV vaccine studies. In 2003, dozens of scientists conducted large-scale early tests on the two AIDS vaccines, ALVAC and AIDSVAX, respectively. As a result, both vaccines did not play an immune role, and the test was declared a failure. Subsequently, researchers in the United States and Thailand used the combination of the two failed vaccines as a new research method and adopted a "prime-boost" immune strategy. The first vaccine, ALVAC, was responsible for stimulating the immune system and making it do Ready to attack HIV, the second vaccine AIDSVAX strengthens the attack and is responsible for enhancing immune response. The RV144 trial officially started in October 2003. The test subjects were more than 16,000 volunteers aged 18 to 30 selected in Thailand. His HIV test was negative, and his risk of infection was comparable to the average level of the general population. Among them, a group of volunteers were injected with the combined vaccine, while the other control group was injected only with a placebo.
- The latest results show that 51 of the 8197 volunteers who received the vaccine were infected with HIV, while 74 of the 8198 people in the control group were infected, meaning that the risk of infection in the vaccine group was reduced by 31.2% .
- U.S. Army Chief of Medical Services, Eriks Kumek, said this was an example of "the first alternative AIDS vaccine successfully reducing the risk of HIV infection."
- The World Health Organization and UNAIDS issued a joint statement on September 24 stating that the results obtained by the United States and Thailand in jointly developing a new AIDS vaccine were "encouraging". "Although the immune effect is limited, it has statistically shown the significance of reducing the risk of HIV infection," said Michel de Wilde, vice president of research and development at Sanofi-Pasteur, France. "Since the discovery of AIDS in 1983, Since the virus, this is the first time that the scientific community has obtained concrete evidence that the development of an AIDS vaccine is feasible. "Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases who participated in the study, said cautiously that this was not" AIDS End point for vaccine research. " Institutions including UNAIDS and the World Health Organization have also expressed "cautious optimism."
- A Reuters report pointed out that the limitation of this vaccine is that if people are already infected with HIV, even if they are vaccinated, the virus will also damage the immune system, which means that once the virus enters the body, the vaccine will not work at all.
- A series of basic studies on new vaccines have yet to be concluded. For example, does the new vaccine have the same immune effect for different HIV and different populations? How long is the effective period of the new vaccine? Why does the new vaccine only show a very limited immune effect?
- It is reported that the details of this trial will be further disclosed at a vaccine conference in Paris in October.
- The progress of Thai AIDS vaccine research also brings hope to China's research in this field. It is understood that, formally approved by the State Food and Drug Administration, China's self-developed AIDS vaccine has officially entered phase II clinical trials in Guangxi.
- Canada's first HIV vaccine approved for human trials in 2011
- At the end of 2011, researchers from the University of Western Ontario in Canada said that they had developed an HIV vaccine that uses genetically modified technology to prevent the inactivation of the entire HIV virus vaccine; unlike other vaccines, it used the entire Viruses, not genes or proteins.
- The virus has been engineered to be "non-pathogenic" at the genetic level, which means that it is unlikely that the subject will be infected with AIDS. The researchers' idea is to prepare the T cells with a vaccine so that they can destroy any cell infected with HIV.
- So far, in preliminary toxicological tests on laboratory animals, the vaccine has been able to stimulate a strong immune response. But researchers still need years to know if it works for humans.
- The US Food and Drug Administration (FDA) has approved research groups to conduct experimental vaccine tests on humans. The first phase of clinical testing was conducted in January 2012, and the test subjects were 40 HIV carriers. This stage will test the safety of the vaccine. If all goes well, the next phase of research will test whether the vaccine is working. The second phase will test the vaccine's immune response to volunteers who test negative for HIV. The third phase will test the effectiveness of the vaccine in approximately 6,000 people at risk for HIV infection. Half of the subjects were given the vaccine and the other half served as a placebo control group. Participants will be followed for 3 years before finally observing how many people are infected with the virus.
- The vaccine, called "SAV001", was developed by Dr. Chil-Yong Kang and his team over a 10-year period. It is also the only HIV vaccine in Canada currently undergoing research. At present, the first phase of clinical trials in the United States has made good progress. Researchers are analyzing the results of the current phase of the experiment to prepare for the next phase of the experiment. [1]
2012 New progress on AIDS vaccine in 2012
- On March 6, 2012 [2] , Cuban experts announced in Havana that the AIDS vaccine developed in Cuba has been successfully tested in mice and will be transferred to human trials.
- The head of the research group, Enrique Iglesias, introduced the results of Cuba to more than 600 participants from 38 countries at the 29th International Conference on Biotechnology held here. The AIDS vaccine, called the HIV-1 Therapeutic Vaccine, is based on a recombinant protein and was successfully developed by genetic engineering techniques. The vaccine seeks to make body cells respond to HIV.
- The vaccine has been successfully tested in mice and will be transferred to human trials. The initial scale of human trials will be "small and closely monitored". The test subjects will be patients "in the early stages of infection with the virus" and "positive antibodies."
- There are about 15.4 million people living with HIV in Cuba, one of the least infected countries in the world. Since the first case of AIDS was found in 1986, 2,580 people have died of the disease in Cuba. Officials from the Cuban Ministry of Health said that Cuba allocates more than 200 million US dollars each year for the prevention and promotion of AIDS and the treatment of AIDS patients.
AIDS vaccine "end of AIDS " is just around the corner
- Original title: South Africa's only partially effective vaccine tested: doomsday or expected
- China News Agency, Beijing, June 21, Durban, South Africa: Researchers announced at the 6th AIDS Conference in South Africa, which closed on the 21st: The world's only partially proven AIDS vaccine has been tested in South Africa. The local media believes that this also means that "the end of AIDS" is just around the corner.
- South Africa's "Sunday Times" said the research project was named "Uhampo" in Zulu, meaning "journey". The project leader is Dr. Glenda Gray of the University of the Witwatersrand. The entire project will last 10 years and will cost a total of US $ 125 million. This project is a "licensed research" and once successful, the vaccine will be put on the market.
- When AIDS was discovered in 1983, it was called "the plague of the century". Scientists believe that the vaccine is the easiest and most effective way to prevent AIDS, and may be its sole end. As of 2010, around 190 AIDS vaccine trials have been conducted worldwide. Among them, China's preventive vaccine research has also entered the phase II clinical trial stage.
- The RV144 vaccine tested in South Africa has been developed for more than 20 years. "This is the only vaccine that has been effective against the human immunodeficiency virus (HIV) so far. It was tested in Thailand in 2009. The next large-scale HIV vaccine Testing will begin in South Africa. "
- A few years ago, researchers from the United States and Thailand jointly conducted a trial of the RV144 vaccine. This vaccine can help some people avoid infection, but its effectiveness is only 31.2%, and it has not obtained the Thai government's production license. According to Mitchell Warren, director of the AIDS Vaccine Advocacy Alliance, an HIV vaccine must be at least 50% to 60% effective before it can be officially put into use.
- The South African Broadcasting Corporation reported that the project will first recruit 100 HIV-negative volunteers in South Africa to participate in the trial, and researchers will determine whether the vaccine is as effective against the South African C strain as it was in Thailand. If it works, from 2016, they hope to have thousands of volunteers participating in the trial. By 2019, researchers hope to come up with some ideal research results.
- Project leader Gray said that researchers will try to make the vaccine survive longer in the body and have better preventive effects. US and Thai researchers have announced for 12 years that they have discovered another vulnerable vulnerability in the HIV shell that could explain the effectiveness of previous vaccines. Even so, Gray doesn't expect this vaccine to be once and for all: "We have only inadequate vaccine prevention so far, which needs to be guarded with male circumcision and antiretroviral drugs."
- According to the World Health Organization, AIDS has killed more than 25 million people worldwide in the past 30 years. In 2011, about 34 million people were living with HIV, of which nearly 6 million were in South Africa. [3]
HIV Breakthrough in HIV vaccine
- Surveys show that 1% of HIV-infected people can survive stubbornly without antiviral treatment. This is because their immune system produces specific HIV antibodies that can identify the characteristics of virus surface proteins and Binds and destroys HIV in the body. Techniques for studying cell surface proteins Fluorescence-activated cell sorting (FACS) can also be used to study viruses, obtain a portion of cell samples, add fluorescent antibodies, and bind to proteins of interest. Cells with a protein recognized by the antibody also turn fluorescent, while cells lacking the protein do not.
- Then you can measure the fluorescence of each cell separately and separate them into a petri dish. FACS is very accurate for large viruses, such as Ebola; but for fine viruses, such as HIV, it has certain limitations. This is also the key to the difficulty of the AIDS vaccine.
- Recently, a research team from France developed a new technology to quickly sort HIV viruses, which is expected to help the rapid introduction of HIV vaccines. The complete research report was published in the journal Cellular Biology.
- The researchers said: "We have developed a system that allows us to analyze HIV at hundreds of speeds per second and isolate the virus based on the function of its surface proteins. We have not used fluorescent antibodies that can directly bind proteins. Instead, we used ordinary, non-fluorescent antibodies linked to alkaline phosphatase (AP), and then we attached a separate virus droplet fluid. Alkaline phosphatase generates a large number of fluorescent molecules inside the droplet, creating a powerful fluorescence. Signal. If the protein does nt have specific properties, the antibody alkaline phosphatase wo nt bind it. In this way, we can study individual viruses and help develop the HIV vaccine.
- We are a microfluidic systemin other words, using technology that manipulates very small amounts of liquid, the entire system is contained on a microfluidic chip, a palm-sized device consisting of microscopic network channels through which liquid flows. These channels are only a few hundredths of a millimeter wide, and the drops used in our experiments were around 30/1000000000 ml. Microfluidic chips provide the specific advantage of contact with pathogens such as HIV when they work. They are completely sealed and therefore very safe to use. Typical flow cytometry systems can produce droplets, so strict controls are needed to deal with harmful bacteria and viruses.
- "Our method is unprecedented in the amount and speed of analysis of the HIV virus, which allows us to quickly test millions of virus variants, greatly accelerating the process of vaccine development."
- "In our experiments, each drop contains viruses and antibodies. Next, we can also add cells to the drops to see if the antibodies can prevent the virus from entering the cells, and all these are fluorescence-activated cells. Sorting is impossible to achieve and complete. We believe that this trial provides more and greater possibilities for future research and brings absolute possibilities for the early advent of AIDS vaccines. " [4]