In the past 40 years, what breakthroughs have been made in AIDS vaccine, and what is the probability of successful listing?

Since the discovery of HIV for more than 30 years, scientists and industries all over the world have never stopped researching and developing HIV vaccines.

The research and development of HIV vaccine is divided into three stages according to time: in the first stage, the research of the first generation gp 120 protein or polypeptide vaccine aims at stimulating the antibody production of humoral immunity, which is similar to the research and development of class A vaccine. Dozens of phase I and phase II clinical trials and one phase III clinical trial all ended in failure. This shows that these vaccines can only induce conjugated antibodies and cannot provide sufficient immune protection against HIV infection.

The second-generation vaccine in the second stage mainly uses DNA and virus vector vaccine, aiming at stimulating T cell immune response. Dozens of phase I and phase II clinical trials failed to develop further. Two phase IIb clinical trials with adenovirus type 5 as the vector show that the vaccine can not only provide effective immune protection against HIV infection, but also increase the risk of HIV infection. This shows that only T cell immunization can not provide effective immune protection.

The third-generation vaccine in the third stage adopts the combined immunization strategy of different vaccines, aiming at stimulating humoral immunity and cellular immunity at the same time. The first vaccine of this kind (RV 144 vaccine) that completed the phase III clinical trial in Thailand used poxvirus vector as the initial immunization and gp 120 vaccine as the booster immunization. The test results show that the protection rate is 365438 0.2%. Although the protective effect is not satisfactory, this vaccine is the only one of the HIV vaccines developed at present, and it has been proved to have a certain immune protection effect in the population. This provides valuable experience for researchers to understand the protective immunity of HIV vaccine and further develop the vaccine, but it is still not enough to produce effective population protection.

After more than 30 years of AIDS vaccine research, researchers have repeatedly lost, but they have repeatedly lost.

A few days ago, one? Johnson & Johnson announces the results of clinical trial of HIV vaccine: 100% volunteers produce antibodies? Weibo caused a heated discussion on the Internet and forwarded more than 20,000 articles within half a day. Many people commented,? Is HIV extinct? 、? Is the AIDS vaccine coming? Is that really the case? Experts say it's not that simple!

It is said that the important progress in AIDS vaccine research stems from the results of a clinical trial published by Johnson & Johnson, which conducted the first human clinical trial of HIV vaccine in the world. The experiment recruited 393 healthy volunteers from the United States, Rwanda, Uganda, South Africa and Thailand. The results showed that volunteers had good tolerance to HIV vaccine, and 65,438+000% of them produced anti-HIV antibodies.

In this regard, many people feel that this is evidence of important progress in AIDS vaccine research. In fact, the working principle of the vaccine itself is to produce antibodies in the human body after injection, thus producing immune function to related viruses.

There are also media reports, which say: After a single exposure to HIV, the infection risk was reduced by 94%, and after six exposures, 66% of the subjects were still free from HIV infection. ? This is more considered as evidence that the vaccine is effective.

Is the AIDS vaccine really coming? Only from the above reports, the research and development of AIDS vaccine may have made great progress. But does this mean that the AIDS vaccine is really coming?

Question 1:? 100% produces antibodies? What do you mean?

Truth: having antibodies doesn't mean it can be prevented.

100% produces antibodies? It is easy to interpret that the vaccine is effective for HIV 100%. But in fact, Professor Zhang of Tsinghua University AIDS Comprehensive Research Center explained:? After all vaccines are injected into the human body, antibody reactions will occur. ? In other words? 100% produces antibodies? It does not directly prove that this is a vaccine that can prevent AIDS. This means that antibodies that produce antibodies and antibodies that produce 100% immunity cannot be directly equated.

Wang Yuge is currently a postdoctoral fellow at Harvard Medical School in the United States. His research field is AIDS. He also holds the same view: the vaccine cannot be proved to be effective. The antibody produced by this vaccine is a normal reaction, but it cannot be said to be a protective antibody. ?

Figuratively speaking, antibodies are equivalent to the police in the body, and the principle of resistance is the bad guys who enter the body. Immune response is the process that the police set out to catch the bad guys, but the police may not catch the bad guys every time. Similarly, the report provided by Johnson & Johnson only mentioned that the experimental vaccine can stimulate the subjects to produce antibodies (police) and produce immune response (catching bad guys), but it has not been confirmed that antibodies can successfully neutralize HIV antigens (catching bad guys).

Experts said that clinical trials are still in the early stage, and the vaccine will be in the case of limited public data. 100% produces antibodies? Explain it as energy? Effective prevention? Not rigorous enough. It will take at least 5- 10 years to finally evaluate the effectiveness of this vaccine.

Question 2:? A single exposure to HIV can reduce the risk of infection by 94%? ?

Expert: This is the result of animal experiments.

As for some media reports, the report said that after a single exposure to HIV, the risk of infection was reduced by 94%, and 66% of the subjects were still free from HIV infection after six exposures. ? Experts believe that, first of all, this is not the result of a clinical trial (which is different from a clinical trial that produces antibodies). Wang Yuge said that the clinical endpoint data of related studies have not been made public.

Second, the so-called vaccine? It can preventively reduce the infection rate after HIV exposure by 94%; Can you achieve 66% complete protection after six virus exposures? This result is not the result of experiments on people, but the result of previous experiments on rhesus monkeys? Preclinical? The results of the research. However, the protective power of human clinical trials of HIV vaccine will not be known until the clinical trials of the vaccine are completed, or even several years later.

In fact, there is a huge ethical risk in conducting related experiments directly with healthy people. After vaccination, healthy people are directly exposed to the threat of HIV. If there is no effective drug treatment, once the subjects are infected with AIDS, no one can bear the serious consequences.

Question 3:3: How far is the AIDS vaccine from us?

Truth: It is not expected to appear for 5 years.

AIDS vaccine, how far is it from us? Wu Zunyou said that this is not easy to predict, but from the current global research, he does not expect it to appear in five years.

A simple phase 3 clinical trial takes five years. In other words, the vaccine worked and the theory worked. It depends on whether it is actually effective. This kind of clinical trial can't be done for five years, and there is no vaccine yet. So it should be said that it is unpredictable. If we have to say, there can be no vaccine in five years. In AIDS research, more research progress is the advent of new drugs. As far as 20 17 is concerned, seven new drugs have been registered in the world. The other is the innovative application of drugs.

Vaccine belongs to the category of drugs, and its research and development and listing are strictly regulated and restricted, which is true in all countries. Both drugs and vaccines need to complete preclinical animal trials and early human clinical trials from 1, 2a to 2b, 3a and 3b. At present, Johnson & Johnson has completed the early trial (the report says that the trial that can produce antibodies is 1/2a phase clinical trial), and its effectiveness and safety need to be tested in subsequent clinical trials.

At present, about 34 million people around the world are infected with HIV, and 25 million people have died of AIDS infection since it was discovered 30 years ago. So far, there is no vaccine that can effectively prevent new infections.