France's anti-epidemic encounters multiple tests again on the first anniversary of the "closure of the city"
International war "epidemic" operation
In response to the turbulent new crown epidemic, France took strict measures to "close the city" nationwide on March 17, 2020.
One year later, the number of deaths from new coronary pneumonia in France was close to 100,000, and the number of new cases in a single day exceeded 30,000. AstraZeneca’s vaccination was suspended, and mutant viruses that may evade nucleic acid testing were found in the country. Many indicators have reached or exceeded 2020. According to the second wave of peak data in the fall of the year, France thus entered the third wave of epidemics and ushered in the third "closed city".
After many tests, the tired France has been unable to do what it wants.
Virus mutations increase the difficulty of prevention, control and detection
As of February this year, at least 4,000 new coronavirus variants have been discovered worldwide.
Among them, the infectivity of the mutated new coronavirus reported in the United Kingdom and South Africa has increased by 50%, the infectivity of the mutated virus reported in Brazil may increase by 80%, and the infectivity of the two mutated new coronaviruses reported in California have increased by 20%. .
These mutant new coronaviruses have mutations in the S protein, which may lead to secondary infections, reduce the effectiveness of certain vaccines, or develop resistance to treatment methods such as monoclonal antibodies, which is the so-called "immune escape."
At present, the mutated new coronavirus reported in the United Kingdom accounts for 73% of the new cases in France. Together, the mutated viruses found in the United Kingdom, South Africa, Brazil and the United States. The more infectious mutated viruses have accounted for nearly five of the new infections in France. Four.
Viral mutations have not only made the French epidemic more and more difficult to control. The mutated new coronavirus that was first discovered in the country recently may evade the nucleic acid test (PCR) of nasopharyngeal swabs, which has made virus detection extremely difficult. The French adopted "detection-tracking" The "isolation" epidemic prevention strategy constitutes a new threat.
Another worrying news is that a confirmed mutant virus patient is infected with the new coronavirus for the second time.
This also means that there is a possibility that the antibodies and vaccines produced by the patients themselves will weaken the effectiveness of the newly mutated virus.
Mourier, head of the Brittany Regional Health Bureau, said, "Because this virus is more difficult to detect, it is more difficult to judge its infectiousness and severity."
As to why the mutant virus can evade PCR detection, French experts currently speculate that there are two possibilities. One is that an important mutation has occurred, so that it can "spoof" PCR detection; the other is that the virus quickly enters the lungs after infection through the respiratory tract. The stock in the nasopharynx is very low, so PCR detection can be "escaped".
At present, French health authorities and experts are more inclined to the second situation.
Dr. Ju Liya, chief scientist of the European precision medicine platform and an immunology expert, said in an interview with a reporter from Science and Technology Daily that if it is the second case, it means that the virus has become more "smart", and it can only occur when the mutated virus causes the patient to appear. After severe illness, the diagnosis can be confirmed by testing the bronchoalveolar lavage fluid. This extraction method is much more difficult than nasopharyngeal sampling.
It is difficult for people with mild or asymptomatic infections to be screened by PCR testing, which may make the French epidemic more difficult to control.
Regarding whether the first case is possible, Dr. Ju Liya introduced that the mutant new coronavirus discovered in France has 9 mutations in the S protein. In addition, multiple mutations have occurred in the primers used in PCR detection. These changes may lead to The test was negative, but there is no explanation for the positive test of deep lung sampling.
The initial infection of the new mutant virus discovered in France can be traced back to at least mid-February, and the infected may have left the area.
Because the mutant strain is difficult to detect, it is impossible to judge whether it has spread. French health authorities have asked all hospitals to strengthen surveillance.
New crown virus infection enters spring high-incidence period
More and more evidences show that the new coronavirus is prone to increase infections in the spring. The reason is that the air conditions, humidity, temperature, and sunlight radiation in the spring are conducive to the survival and spread of the new coronavirus, and the other main reason is that the air is high in the air. Concentrations of pollen and pollutants can promote new coronavirus infections.
According to a report published online by the Proceedings of the National Academy of Sciences on March 8, researchers compared the air pollen concentration data of 31 countries and regions with the number of local new crown infection cases during the same period, confirming that the pollen concentration and infection rate increased. Correlation.
The surge in the number of COVID-19 infections in the spring in Western Europe may coincide with the flowering season of trees. The high temperature in Western Europe from March 10 to 14, 2020 has increased the concentration of pollen in the air, and the COVID-19 epidemic has shown an upward trend after 4 days.
In France, more than one-tenth of the population is affected by "hay fever" during the flowering season.
Nampancy, an allergy expert at the Ecole Polytechnique de Paris, said that pollen caused the increase in new crown virus infections mainly not because it can act as a virus carrier, but because the inflammation caused by pollen can become a breeding ground for new crown virus and may be related to the occurrence of severe illness. Inflammation is characterized by increased cell activity, and the new coronavirus can use this activity to accelerate replication.
Isabella Annecy-Mesano, research director of the French National Institute of Health and Medicine, pointed out that pollen contains allergens and other molecules that have an effect on the immune system, which can cause a certain vulnerability in the respiratory system.
The spread of pollen may lead to a decline in immunity, creating a state that is conducive to inflammation, and weakening the defenses of the respiratory tract against viruses.
As France and other Western European countries enter the wet and cool flowering season, the turbulent epidemic must be controlled during this period, and the blooming of spring flowers is undoubtedly "worse worse."
Tired of letting the "weapon of closing the city" greatly reduced
In response to the third wave of the epidemic, the French government decided on the 18th to implement a third "cities closure" and to block 16 provinces with severe epidemics for at least four weeks.
Compared with the previous strict ban, the "city closure" has been greatly "relaxed". The public can go out during the day to breathe fresh air, participate in sports activities, and the distance from home has been expanded to 10 kilometers, and there is no longer a time limit. All schools will continue as usual. Class.
In the past year, the French people have spent more than 200 days in the foot restraint and curfew, which has caused the people to become tired of "closing the city."
Although there have been no violent demonstrations by the Netherlands and other countries in France, whether the people can strictly abide by the blockade regulations and their tolerance for the rules are important factors that the authorities must carefully consider.
The saturation rate of intensive care beds in the Paris region has reached 101.7%, and the implementation of strict foot-free measures has long been imminent. However, the population of this region accounts for nearly one-fifth of France, and its GDP accounts for 31% of France. France takes into account many factors of economy and people. , The blockade of the Paris region could be delayed, and finally the "flexible" version of blockade measures was reluctantly adopted, which greatly reduced the ultimate "weapon" of "closure", and its effect was also difficult to see immediately.