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A new coronavirus vaccine developed by the University of Oxford in the United Kingdom has entered human clinical trials.
On April 23, a new coronavirus vaccine developed by the University of Oxford in the UK began human clinical trials. At the same time, the United Kingdom began manufacturing approximately 1 million doses of vaccines. The results of clinical trials coming out this fall are expected to show that these 1 million have started production. Vaccine safety.
In early March, the United Kingdom proposed the controversial theory of mass immunity: the theory was that the new crown virus was introduced to open the city gate and approximately 60% of the population was infected with the virus to produce antibodies. Chen Zhengming, professor of epidemiology at the University of Oxford in the UK, commented at the time that the UK’s epidemic prevention strategy was almost ruthless and rational.
The mass immunization was met with much criticism, and the British government subsequently changed its strategy and announced more aggressive countermeasures such as the closure of the city. But as of April 22, the number of people infected with the new coronavirus in the UK reached 129,000, of whom around 17,000 died, making it one of the epidemic centers in Europe and the world.
The epidemic is spreading worldwide, and more countries around the world pin their hopes on the advent of vaccines. Are group immunization and vaccination the same? Is it the waiting period for the vaccine to be a group immunization in disguise? Is the vaccine necessarily effective? How should the future global epidemic prevention strategy be planned?
BBC Chinese interviewed Chen Zhengming, professor of epidemiology at Oxford University, to verify these problems.
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Chen Zhengming said the virus cannot be removed (temporarily), which is now a common consensus in the scientific community.
BBC Chinese: The principle of the vaccine is to inject a part of the virus into the human body so that the body produces antibodies; and the controversial group immunization previously launched by the United Kingdom also allows the public to infect and produce antibodies. What is the difference between the two? Why wait for the vaccine?
Chen Zhengming: Both vaccines and mass immunization produce antibodies for protection. However, the vaccine is controllable, and the uncertain factors of group immunization are too great and the risks are great. No one will deliberately become infected and produce antibodies, which is a necessary scientific concept.
Mass immunization has many misunderstandings in the early stages of the anti-epidemic period. Mass immunization seems to be interpreted as letting people infect, regardless of the life and death of citizens, everyone infecting. One is inadequate government communication; the other is the cultural differences between East and West; the third is a media hype that attracts attention.
Mass immunization is the theory that if 60% to 70% of people are infected without any epidemic prevention, the virus will die naturally.
Actual mass immunization does not actually need to achieve this infection rate. Why
In fact, it is impossible to live a normal life after the outbreak, and everyone will take protective measures. In this case, if the population’s immunization or infection rate can reach 20%, plus some social distance and other measures, the new coronavirus will obtain a good group immunization.
Mass immunization is not general. Because we still need to understand the virus. The virus mainly affects the elderly, and its case fatality rate is particularly high. Most young people actually have a very low case fatality rate, a small percentage. Therefore, it is very important to protect these high-risk groups, such as the elderly and people with basic illnesses.
Others may gradually regain their normal lives. In case of infection, they may not cause serious health risks and can recover quickly. Furthermore, it will generate protection and contribute to the whole of society.
Before the vaccine was released, it was probably the way in Germany, Japan, the United States, and Europe. This is a last resort. It is impossible to seal the city forever and society to close forever.
BBC Chinese: You mentioned that the youth case fatality rate is only a small percentage, but nobody wants to be a few hundred percent.
Chen Zhengming: It’s like that, so nobody wants to take the initiative to get infected. From the perspective of group immunity, there is uncertainty. If you have to resume production and study, you must plan. Children and adolescents in schools are very infectious and very immune. Most of them can recover after infection, and there is almost no death. Even if there is death, there are also individual diseases. For example, some children have diabetes.
So this group of people can be sure to go back to school. Also, of course, contact with the elderly should be blocked. Therefore, some basic data (for reference) is needed in the decision-making process.
BBC Chinese: Can the virus be eliminated after the advent of the vaccine?
Chen Zhengming: The biggest problem with the new coronavirus is that the vaccine is still in development, and may be out in the second half of this year as soon as possible. But there is still uncertainty.
Whether the first vaccine will have a protective effect is unknown, and secondly, its safety is unknown.
The third virus is unstable and will mutate. Perhaps the vaccine has been developed and will be given over a year or two. Like the flu shot, it is changed every year because it changes quickly. So the new corona virus can also have the same situation.
It can develop two years later, and it has no protective effect, or the protective effect is weak. Then you have to study again.
So there is still a lot of uncertainty about how to control the virus. But vaccines are definitely the most important means of preventing infections that concern everyone.
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BBC China: China has resumed production and production, the public seems to have accepted the job while fighting the epidemic“Normal“. The vaccine will not be successfully developed until the second half of this year or next. Now to the window period of successful vaccine development,Is it going objectively?Disguised group immunity?
Chen Zhengming: (helpless sigh) This is a last resort. Because any antiepidemia must deal with both extremes, as well as a balance, on the one hand to protect health, on the other hand to protect production. After all people and economic livelihoods are closed, the problem is not a big one in the short term, and a long time can bring major secondary damage. The possible impact on people’s livelihoods and health may outweigh the damage caused by the new coronavirus. This is a (problem) that all countries face and that (city closure) cannot be implemented in the long term. We must lift the ban, we must learn to “dance with the disease.”
“Dancing with the disease” does not encourage everyone to take the initiative to infect the virus, but there is a risk of infection. Therefore, from a national perspective, it is impossible to fully unlock. China is now trying to fully unlock it, but it is actually very difficult to do and everyone is concerned. In many public places, gatherings, and ball games such as densely populated and closed environments, we are still very cautious. Or it has not fully recovered.
This is certainly the case in European and American countries: the basic production line is restored and some things may not be restored. Even after recovery, personal risk assessment is different, such as being shy or cautious, you can wear a mask or choose not to go out, etc. This can also reduce the risk of infection and the likelihood of virus transmission to some extent.
BBC China: Some media compared the research and development of this new crown vaccine to a competition. What do you think?
Chen Zhengming: Putting it under the big picture, this is a virus competition, not a competition between countries. From a small perspective, the company’s successful R&D will bring benefits, which is also reasonable, because it also invested many resources and costs in the initial stage.
Everyone’s understanding of viruses is constantly changing. Everyone in (China) also realizes that the virus cannot be completely removed. Although the campaign against China’s epidemic has been very successful in the past two months, it has basically been cleared in many places. But now there can be a second wave and a third wave.
Viruses (for now) cannot be killed, which is now a common consensus in the scientific community. Because there are no specific vaccines or medications, they have spread throughout the world and have many invisible transmissions, it is unpredictable and highly contagious. The UK is an example: only a few dozen cases (confirmed cases) in February, and now there are almost 200,000 (confirmed cases) in April. And we may not be able to estimate the actual number. It can be multiple times or even ten times.
So this virus is difficult to prevent. Once the vaccine is developed, it is a great help to humans. Without the development of vaccines, it is difficult for society to return to normal.
Even if it was open, everyone was terrified. Wearing masks every day, he doesn’t dare enter the restaurant, he doesn’t dare take the plane, everyone is worried about life. This situation must be changed: the vaccine is the only most effective and safest way.
Different countries are developing vaccines, which is actually beneficial. Because it is difficult to predict which method will be successful, some will certainly fail. It is difficult for anyone to predict. Therefore, if the bulls go hand in hand, the probability of success will be higher.
Even if the vaccine is developed successfully, vaccine production cannot reach one billion a year in the short term, there must be a very slow process. Each country will protect its citizens in the interest of its own country. If the UK develops it, it will definitely be used for the UK first and will not be exported. It is impossible for everyone in the UK to have it. For example, key populations such as the elderly, medical personnel, and front-line personnel will be vaccinated first, and then expand when there is a surplus (vaccinated population).
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There must be a process. In this process, all (countries) go hand in hand and can develop successfully. The positive impact will be very rapid, and the epidemic will soon be controlled worldwide.
The epidemic situation is useless for a country to control it, and it will revive, and other countries will spread it. For real control, it still depends on the vaccine, this is how smallpox is eliminated. But for the new coronavirus, even if research and development is successful, the virus may appear highly mutated, rendering the vaccine ineffective or weakening its protection. If there is no vaccine, only through the so-called “group immunization” route, which is also useless. If a considerable part of the population gains natural immunity after becoming infected with the virus a few years later, the spread of the virus will gradually decrease. Of course, the premise is to protect the elderly and high-risk objects.
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BBC Chinese: How to prevent the epidemic in the next stage?
Chen Zhengming: Currently, many problems cannot be absolute and there is no possibility of zero risk. It is just to minimize the risk. This is a very important basis for decision making.
China may have fared too well in the initial stage, emphasizing zero risk, but it is actually very tiring, I suppose it may be difficult to maintain. Now the number is small, it may be fine.
Singapore is a good example. (Previous) Measures like containment have been successful, and there will be no way after the number of people increases. Unpredictable
There may be certain risks in unlocking. This risk must be well communicated with everyone: on the one hand, individuals also have a responsibility, they do not pressure or gather, they minimize public activities and protect themselves as much as possible; From the government’s point of view, they also have responsibilities, such as large-scale events and large closed environments that may not be released immediately. You can also follow the epidemic (go). These are risk assessments, how to minimize them.
This requires an accurate judgment. The future strategy (prevention of epidemics) is the combination of control and release, strong loosening and strong loosening for a time. Then it varies from place to place, for example, if the London outbreak is severe and restaurants are not open, the infection rate in Scotland may recover first.
Another is protracted warfare, which is a (new) normal. Before the future vaccine comes out, our normal lives will change. Even if it is not sealed, it means restoring the past life situation as much as possible, but in fact it is difficult to achieve (complete restoration). I can not do it
BBC Chinese: For the scientific community, does it make sense to find the source of the virus?
Chen Zhengming: You can understand the intermediate host and cut the source of animal transmission. Additionally, you can understand the mutation status and characteristics of the virus to provide a better scientific basis for developing a broad-spectrum vaccine.
