THE REASON FOR THE FAILURE OF THE AIDS VACCINE TRIAL IS UNKNOWN, GIVE UP OR CONTINUE.

On September 18,, the clinical Phase IIb trial of the Ad5 vector vaccine, considered the most promising AIDS vaccine in the world, failedOn September 21st, the trial was called off, causing a great shock to the entire field of AIDS vaccine researchCan the road of AIDS vaccine development continue? Is it time to consider "flying up"?On the afternoon of October 13, on the sidelines of the 90th anniversary academic conference of the Beijing Concord Medical College, the reporter interviewed the inventor of the AIDS "cocktail therapy", the director of the Diamond AIDS Research Center of Rockefeller University in the United States, Professor He Dayi, a foreign academician of the Chinese Academy of Engineering, the director of the AIDS Research Center of the Chinese Academy of Medical Sciences (Beijing Concord Medical College) and the chief scientist of the National "973" AIDS Research ProjectThey have all made it clear that they will not give up their research on the AIDS vaccine, because the AIDS vaccine is still the best hope of mankind to curb the AIDS epidemic"The AIDS vaccine research has suffered a fatal blow
," the September 21 issue of the Journal of Science said the vaccine failed for an unknown reasonAs recently as September 18th, the much-anticipated aids vaccine, the replication of the defective Ad5 adenovirus vector vaccine (Ad5 vector vaccine) Phase II.b, failed because its medium-term safety data analysis showed that the vaccine neither protected volunteers from HIV nor reduced the viral load in infected personsThe vaccine was presented by Merck and was conducted by the National Institutes of Health's Institute of Allergy and Infectious Diseases, the AIDS Vaccine Trial Alliance and MerckSince November 2004, 3,000 HIV-negative male and female volunteers from high-risk groups in South America and North America, the Caribbean and Australia have participated in a clinical trial called Step Step (STEP)The volunteers ranged in age from 18 to 45Prior to the trial, none of the volunteers were infected with HIV, but were at high risk of AIDS, including homosexuals and sex workersThe volunteers were divided into two groups, one with the AIDS candidate vaccine and one with a placeboA total of 1,500 volunteers, the vast majority of whom were gay men, participated in the trial, with 24 of the 741 volunteers vaccinated at least once infected, compared with 21 of the 762 people in the control groupMore disappointingly, there was no difference in the level of viral load in the two groups of test subjectsResearchers have been optimistic about the Ad5 vector vaccine, which was developed in a new way Instead of activating antibodies against HIV, as most conventional vaccines do, it specifically targets the immune system's anti-Trump T-cell response Hope that HIV "settled" before the fight back, or even if infected, at least the infected person's body of the virus load to control a certain level Good immune effects have been seen in monkeys before Professor He said the reasons for the failure of the "step-by-step" test are unclear and the test data need to be fully analyzed before a definitive conclusion can be reached The vaccine uses adenoviruses as a vector to bring three gene fragments of HIV into the body However, for many people, they are strong enough to pre-exist against adenoviruses As a result, this can damage adenovirus vectors and lead to a reduced vaccine effectiveness However, even if the trial required more than half of the volunteers to have only lower adenovirus pre-depositican immunity, the vaccine did not show the desired effectiveness In the research vaccine design ideas are much the same
according to Zhang Linxuan, the current world has entered clinical trials of more than 30 AIDS vaccines, most lying in Phase I to Phase II clinical trial stage The types of vaccines include adenovirus vector vaccine, pox virus vector vaccine, DNA vector vaccine, and subunit protein vaccine and subunit peptide vaccine, most of which are designed in much the same way as Ad5 vector vaccine China's current AIDS vaccine strategy, some of which is also induced T-cell immunity Experts at home and abroad have pointed out that the AIDS vaccine was developed since the mid-1980s, and still faces many challenges: HIV is a "mobile target", both in the infected body, and between groups are highly mutated; Broad-spectrum neutralizing antibodies; HIV strains isolated from humans do not infect animals, so no ideal animal model of vaccine development has been found so far; the correlation between HIV immunization and protection is still unclear, so there is a lack of an effective criteria in vaccine research to judge whether one candidate vaccine is superior to another He Dayi, Zhang Linxuan said that AIDS vaccine development is difficult, the key is "HIV is very 'thieves'." HIV antibodies have no way to catch the protein on the surface of the virus, and then kill the virus." They believe that the failure of the Ad5 vector vaccine suggests that the next step should focus on the development of a vaccine that induces the production of HIV antibodies, or induces a cell-mediated immune response and induces antibodies to produce two effects superimposed vaccine It's hard to explore on September 27th Seth Berkley, the head of the International AIDS Vaccine Action (IAVI), called through the Los Angeles Times: "Vaccines remain our best hope for reversing the AIDS epidemic, and we cannot give up on the AIDS vaccine." Seth Berkley says failure is the mother of success The lessons of the Ad5 vector vaccine trial will take some time to explain, but the cancellation of the trial is far from the end Many studies suggest that the body's immune system is better at fighting HIV than we initially thought Most infected people can suppress the virus for many years before developing AIDS A small number of people have never been infected, despite repeated exposure to HIV Others, although infected with HIV, have not developed AIDS If we understand the mechanism behind these phenomena, we can get ideas and clues in vaccine design to "equip" the immune system to fight HIV infection Compared with therapeutic drugs, the commercial value of the vaccine is low, so the main input aids vaccine development, or government departments, universities and research institutes, companies involved very little, only a few in the world However, the company's involvement did facilitate the research process: so far, there have been two vaccines in large-scale clinical efficacy trials worldwide, both developed by government departments, research institutes and companies One of them is the ad5 vector vaccine that has just failed Merck, which has spent 10 years developing the vaccine, had high expectations Expert analysis, Ad5 carrier vaccine "abandoned", the pharmaceutical industry investment in AIDS vaccine development behavior may have some impact, but only temporary Although measures to address HIV/AIDS should be all-round, including education, prevention, treatment and care, developing a safe and effective preventive vaccine is the only effective way to end the epidemic of the disease, said Mr Zhang The development of AIDS vaccine is difficult, but also need son of scientists around the world to continue to explore