On April 15, after a few hours of video conference with the governors of the states, German Chancellor Merkel decided to lift the control measures taken by the epidemic in stages.From time to time, allow primary and secondary schools to gradually resume classes.
A report from the German Medical and Health Association (DGKH) stated that Germany is currently in the first stage to socialized social isolation for the purpose of blocking and delaying the proliferation of epidemic, preventing the heavier supply system and other key supply systems.Since then, the second stage is to relax and isolation at the same time, and at the same time ensure the sanitary environment and sanitation; the third stage is to cancel the isolation and continue to maintain the sanitary environment; the fourth stage is to fully return to normal life.
As of April 20, Germany confirmed a total of 1,45184 cases, with a total of 4,586 deaths.The German Ministry of Health officials have previously explicitly stated that the German infection rate has continued to decline.
A few days ago in Merkel and the governor of the governor of the states, a research team at the University of Bonn University in Germany announced a preliminary assessment result of random sampling tests.In the earliest severely affected area of Germany, the town of Gandert, Hainsberg County, the research team, and the throat wound nucleic acid test and serum science test of 1,000 residents were found in the research team.14%of people have carried antibodies.
After eliminating the overlapping crowd between the two groups, the research team concluded that 15%of the people in the town were infected with the new crown virus with a mortality rate of 0.37%.
The research report also believes that the immune effect of the group has begun to appear and clearly proposes that Germany's termination control measures transition from the first stage to the second stage.One of the important steps of transition is to focus on crisis management to reduce the number of cases of severe infection, such as the number of cases of intensive care, use of ventilator and death, instead of reducing the number of overall cases without considering the degree of crisis of cases.Essence
While attracting widespread attention, the results of this study have also been questioned, such as whether the detected antibody is reliable, the sampling method is scientific, and the results are not published in academic journals.
Lu Mengji, a professor at the Institute of Virus Research, Germany and the University of Medicine, Germany, said in an interview with China News that there are experts from the academic community.Antibody.According to the information of the experts of Charut Hospital, the interference rate of the detected antibodies is about 4 %, so the credibility is still very high.
The gap between the positive rate of nucleic acid and the positive rate of serum is very large
China News Weekly: Germany has just conducted a sample survey on the town of Ganggelt, which concluded that the infection rate and 0.37%of the infection rate were 0.37%.You said before that this survey is of great significance to judge whether Germany's formation of group immunity.What kind of conclusions can I come out now?
Lu Mengji: This preliminary study can explain some problems, and of course it needs to be further verified.Germany has launched more serum survey projects, and everyone is looking forward to more convincing results.
First of all, the 15%infection rate is indeed very high.The carnival event of Ganggelt in Heinisberg County was held on February 15th, and the sample was in early April, six weeks apart.During this period, in the case of a very strict isolation control measures, the virus is still spreading rapidly, indicating that the transmission ability of the new coronary virus is very powerful.
Gangegelt implemented social distance control measures at the end of February, and is the longest region in Germany.Even so, the positive cases of Nuogelt's daily nucleic acid testing are still increasing, and basically dozens of cases have been increased daily.
At present, the proportion of nucleic acid positives detected is only 2%, but in fact 15%of people are serotonia positive, and the gap between the positive rate of nucleic acid and serum positive rate is very large.This gap shows that some people do not receive nucleic acid testing because they have no symptoms, and no one knows that they have been infected.This is another prompt given by serum detection: the new crown virus not only spreads quickly, but also has a wider dissemination range than what we know.
From the preliminary data of Gantalt, the number of asymptomatic virus carriers in the local area is very large. They do not know that they are infected and continue to spread the virus. This is the problem we are currently facing.The spread of the new crown virus is too fast, and the vaccine is difficult to catch up.
But from another perspective, as long as the goal is not to achieve zero propagation, then this kind of communication is beneficial, because this communication does not cause any pressure on the medical system, and it has produced many immunity.
Gangegelt has a 15%positive rate, but it is the earliest region of the German epidemic. At present, the positive rate of serum academic across the country will not be so high, and it may still be single.There have been more than 130,000 confirmed cases in Germany, and most of them have been cured. The current number of patients is about 50,000. There must be many unlimited symptoms that are not detected.We speculate that the transmission of the virus of Gantalt is about a month faster than the country. If the detection data in this area is correct, that is, there is still a month difference, Germany will also reach a higher positive rate.
The results of the latest serological survey conducted by the University of California Stanford in the United States also reminded that the total number of infected people may be 50 to 80 times that of the number of infected people.Positive.
China News Weekly: Does a person with immunity mean that it will not be infected with the new crown virus?How long will the immune effective cycle be?If the virus mutates, is the immunity produced by the infected and healed people?
Lu Mengji: Researchers in Beijing have done related animal experiments. When the monkeys infected with the new crown virus were recovered, they were very resistant to the virus attack.From the perspective of virus and immunology, if a individual can control the virus, then he has the same control ability in the face of the next infection, and can play a role in a long period of time.This is a feature of immune response.After some virus infection, such as hepatitis B virus infection and rubella virus can also be immune for life.
Under normal circumstances, comprehensive immunity can be obtained through infection, that is, cellular immunity and antibody immunity.At present, there is no good research on the patients' immunity produced by patients in the new crown virus. This is the direction that scientific research urgently needs to be strengthened.Without this knowledge, the research of vaccines is also limited.If you don't know how immune control the virus, you don't know how the vaccine should be designed reasonably.
Compared with the immunity caused by his own infection, most of the immune response produced by most vaccines is relatively single.This is because the vaccine stimulates the immune response of the human body.This is why many vaccines have to be hit for a while and then strengthen them, otherwise the immunity obtained will be lost.In addition, some viruses will mutate, such as flu, so you need to re -get new vaccines.The immunity caused by human infection virus is more resistant to virus variation. Generally speaking, it is also the strongest and most complete immunity.
But this is not to say that the vaccine is not good, and the vaccine can accelerate the start of the immune system.If the virus is infected with the respiratory tract first, it takes time to copy to a certain amount in the upper respiratory tract to spread into the lungs.If the immune response can strive for two days, the virus can be stopped in time to prevent the spread.Therefore, asymptomatic people are the successful immune control, controlling the virus infection in a very low amplitude, and does not spread it to other places to cause damage.
China News Weekly: Ganggelt has 14%of the infection rate. To what extent can it slow the spread of virus?How much can the R0 value be reduced?
Lu Mengji: If 14%of the population is immunity, the virus spreadsThe rate has decreased accordingly. If it is calculated according to the natural R0 value of the new coronary pneumonia virus 2.5-2.7, then the new coronary pneumonia virus R0 of Ganggelt is about 2.1-2.3.
Group immunity is the most viable solution at present
China News Weekly: After seeing the data of 15%of the infection rate, you posted a circle of friends saying that group immunity is not a dream.The general concept of immunization of groups believes that 60%to 70%of people may have immunity, and the virus cannot be further spread.15%of people produce antibodies, shouldn't the threshold of the group immune be far away?
Lu Mengji: To achieve group immunity, the most important thing is how to achieve the goal, what are the costs need to pay?It doesn't make sense to do a lot of death at the expense, or from time to time, it takes 10 years to complete.
Now it seems that even if the social distance control measures are strictly implemented, the new coronal virus can infect 15%of the local people within almost 6 weeks.With such a strong communication power, it is inevitable, and a large immune group will soon produce a large group of immunity.If Germany relaxes control in early May, the virus spread is likely to be faster.
In addition, look at its lethality, from the data detected by the Gandert serum, the local infection mortality rate is 0.37%, and the number of deaths is still many.But to watch this problem dynamically, we will not keep the infection mortality at the same level.
The lethality of the new coronal virus is reduced, and the cost of achieving group immunity will be reduced.In this case, its spread is fast, resulting in a large number of people with no symptoms, and its lethality is becoming more and more controllable.Under these premise, group immunity is certainly not a dream.The speed of forming group immunity may be fast, not far away.
China News Weekly: You just said that through preliminary data, you can see that the spread of the new crown virus is too fast, and the vaccine is difficult to catch up.Does this mean that humans cannot wait for vaccines or block viruses by manpower. Only group immunity is the most feasible solution at present?
Lu Mengji: Yes.For the cases of great epidemic diseases around the world in the past, for example, in 2009, the popular A H1N1 flu virus, the earliest outbreak of Mexico in April 2009, slowed down in summer, the second wave of autumn, reached the peak of spreading at the end of the year.It swept the entire United States and spread to Europe.At the beginning, everyone was also panicked, thinking that the virus was very powerful, because the earliest data was 27%of the mortality of the disease, but then gradually discovered that this data appeared at the time because everyone did not know how many people were infected.Finally, the type of H1N1 flu is about 0.1%.
In the later stage of the influenza of H1N1, many countries also conducted serum surveys, but everyone didn't pay much attention.The type A H1N1 flu has been spread from April to the end of the year. The positive rate detected by the serum survey of school -age children in the United States is 60%.Of course, at that time, various countries did not take too many control measures in the later period.However, the R0 value of the type A H1N1 influenza is estimated to be only 1.2, and the propagation power is not as good as the new coronary virus.Through this number, you can see that the 60%positive rate of group immunity sounds far away, but for a global popular virus, it can be completed within a few months.
The German emergency and the company negotiated the vaccine production. By the end of 2009, 35 million vaccines were provided. As the epidemic had passed, the public had no motivation to take over.500 million euros.It can be seen from this example that the vaccine has not played a decisive role.
If the spread of the new coronal virus is fast, the vaccine should eventually be used for the protection of high -risk population, causing them not to be harmed by the virus.
Let the school part of the school start, it will increase the virus transmission
China News Weekly: In response to the preliminary results of the serum testing of Gantalt, DGKH issued an evaluation report, which proposed the strategy of seal control measures taken by the epidemic in four stages.Can this be understood as the four -stage strategy of the German group immunity?
Lu Mengji: Germany is still in the first stage and began to enter the second stage in early May.Since it has been decided to coexist with the virus, it is impossible to avoid the spread of the new crown virus at a considerable level. The best way is to spend the most difficult stage of group immunity at the fastest speed.Because isolation measures have greatly affected society, economy, and international exchanges.As a result, everyone can neither live normally, nor completely control the spread of virus, and the casualties will still exist.
The fastest speed is the premise: the hospital must have sufficient resources and ability to treat it, that is, to control the casualties.If the second wave of the new crown virus in autumn and winter can reach a large range of immunity, it will be greatly helpful for successive prevention and control.Of course, it is still impossible to do now, after all, this virus has a certain lethality.Therefore, Germany now adopts the method of discounts carefully to minimize the lethality of the virus, and then open on this basis, allowing the transmission speed of the virus to accelerate accordingly, and has a purpose to regulate control.
Therefore, in the case of protecting high -risk groups, such as closed nursing homes, people with basic diseases such as diabetes strictly work strictly at home work, allowing other people to be immunized first.With the increase of the entire group's immunity, the speed of virus transmission slows down naturally.Then the degree of freedom of the entire society will become higher and higher, and most people will gradually feel that there is restrictions.
China News Weekly: What measures to change will accelerate the spread of the virus?
Lu Mengji: School starts.In the past, there were many detection statistics of epidemiology, and the virus's spread in school was very fast.Children are more susceptible and like group activities, which will drive the dynamics of the entire virus spread.
Of course, the premise is that the speed of spread must be controlled.Therefore, even if the German school starts, it will take prevention and control measures in the school.This accelerator needs to be controlled, and the timely decision is to speed up or slow down.According to the current investigation and research, the impact of the new coronal virus on children is very small, and it can even be said that there is almost no impact.
The current gradual opening up in German society is still very careful, which contains a lot of components that maintain social distance.It is unclear what the impact of the starting school on the speed of virus spread is still. Therefore, consider that some students who have restored some schools first have a class, requiring a class to not exceed 15, and each student requires a distance of 1.5 meters.The school should implement the prescribed sanitary disinfection measures.The school is a accelerator for virus transmission. It is likely that the speed of spreading will increase significantly at once, and it must be controlled within a limited scope of safety.First look at how the effect is. If it is still controllable, the control measures will be released faster. More school grades can recover the class normally, and parents work normally.
China News Weekly: But there are also younger infected patients developing severe or even death. No matter how low the proportions are, these lives are the only one in the family.
Lu Mengji: There are indeed cases of young people who died of new crown virus.But in fact, the most affected is the high -risk group, that is, the elderly over 65 years old and those with basic diseases. This is a crowd to strengthen protection.
Moreover, we should look at this issue like this: Germany's natural death numbers each each year is about 900,000, and the number of natural deaths per month is about 80,000.Death will occur in the middle of the incident. For example, there are so many car accidents every year, but everyone is still driving.Smoking, more deaths caused by alcoholism, and we cannot prohibit.There are thousands of cases of death in Germany due to the death of new crown virus, while Germany and China have tens of thousands of related deaths caused by influenza each year.Requires the society to close the society.
What we need to talk about now is science, moderate and sustainable, and these three are indispensable.If it may cause 1 death because the new coronary lung virus may cause one death,It will be sealed throughout, then this is not moderate.If the economy is not good, clinical treatment will lack economic support when encountering other problems later, which will lead to more people who die from other diseases such as cardiovascular disease and cancer.The secondary disaster caused by the entire society may cause more people to die, and closed society is unsustainable.
China News Weekly: To achieve school immunity first, parents go to work normally, how long does it take to gradually achieve the vitality of group immunity recovery?
Lu Mengji: It is difficult to predict.At present, the German infection crowd is not too big, but it is expected that students in some schools will be more clear after returning to class for one month.Germany can initially solve the problem of this group of immunity in three or five months. It still takes one to two years. It is necessary to track the timely serum detection. According to data analysis, it will be clear.
The spread of the new crown virus has actually been in our hands to a certain extent.If you are sure to pursue group immunity, the faster and better in principle, the better and resolutely implement it.
The most ideal estimate is that if the German medical system can further prevent the severity of the new crown pneumonia, timely discover time treatment, and even two or three months, it can develop some antiviral drugs to determine their therapeutic effects and help high risks to high risksPatients pressed the virus early, and the German group's immune process will be very fast.Essence
China News Weekly: In the process of achieving group immunity, you have said that people who have already infected the virus are of great significance, and they can use it to use infrastructure sensitive areas.How do you play the role of these people, do you have some specific suggestions?
Lu Mengji: The most direct way is to allow doctors who have been infected with the new coronary virus and recovered, and go to the ward of the ward of patients with high -risk people including immune defects, cancer, and organ transplantation.Those who have infected the virus and produced immunity can also do work that often contact the elderly, such as going to the nursing home to work.These people are the firewalls that play the most important interception of virus.
As the school starts, children can visit grandparents after they have immunity.In Germany, the isolation of the elderly brought them a lot of loneliness, and many people warned.The most important life content of many elderly people is to reunite with family members. Experts have pointed out that if they are simply strictly guarding the death, loneliness will also cause tens of thousands of elderly people to die.
We used to say that group immunity is a by -product prevention and control process, not the goal deliberately pursuing.Sweden has a greater risk of preventing and controlling the prevention and control strategy of group immunity.What the final result is to be tracked and studied.
