According to the latest data released by the Ministry of Health of India on the 6th, the number of confirmed cases of new coronary pneumonia in India rose to 21077410. In the past 24 hours, there were 412,262 newly confirmed cases in India, a record increase every day; 3,980 new deaths and a total of 230,168 deaths. The pandemic situation in India is getting worse, but there is no end to this crisis. Some countries in South Asia and Southeast Asia are also facing the impact of a new wave of pandemics.
Why is the pandemic intensified in these countries? Will the mutation of the covid-19 reduce the effect of the vaccine? Will India’s difficult pandemic situation affect my country’s pandemic prevention and control? A reporter from People’s Daily Online on these issues of public concern interviewed Li Lanjuan, academician of the Chinese Academy of Engineering and director of the State Key Laboratory of Infectious Diseases.
The mutated virus that is circulating in India has undergone double or even triple mutations.
P.C. Forum: The spread of the mutated covid-19 virus in India and its neighboring countries has attracted much attention. In your opinion, why has the pandemic intensified in these countries?
Li Lanjuan: The covid-19 that is active in India and its surrounding countries has mutated. These mutations may lead to immune escape and increased infectivity of the virus. It may be an important reason for the large-scale pandemic of the covid-19 pandemic in the countries mentioned above. As for these mutations, the covid-19 virus Impacts the pathogenicity, transmission rate, and other disease characteristics that still need further observation and research.
Judging from the experience of global pandemic prevention and control, no matter which country or national system, if the source of infection can be found and controlled, the route of transmission can be cut off, and the susceptible population can be protected. The pandemic can be slowly controlled. Obviously, India and its neighboring countries are not doing ideally. If the source of infection is not controlled and isolated, the spread of the pandemic is inevitable, and it will spread on a large scale. In this way, many people must be infected, and then severe, critically ill, or even death cases will occur. Therefore, infectious diseases do not distinguish between national borders and races. As long as prevention and control work is not done in place, it will spread.
P.C. Forum: Recently, the “China Centers for Disease Control and Prevention Weekly” (English) disclosed 3 confirmed cases of the covid-19 entering Chongqing. Genome sequencing revealed that the virus-infected by these 3 confirmed patients was a variant virus circulating in India. The infection may have occurred in India. Why do viruses often mutate? What are the characteristics of the mutant virus discovered this time?
Li Lanjuan: The mutation of the virus is inevitable because the virus itself is also a living thing. While it invades and infects humans, it is also constantly adapting to changes in the outside world. The difference is that the speed of virus mutation is not the same. Some are slow. Some are fast.
The covid-19 is an RNA virus, and genetic mutations are the most common biological characteristics of RNA viruses. Still, whether these mutations will enhance virus infectivity, transmission, and pathogenicity needs further research. But for now, the mutated virus circulating in India has undergone double mutations or even triple mutations.
We need to make the population’s vaccination ratio as high as possible
P.C. Forum: Will the mutated virus affect the effectiveness of the vaccine?
Li Lanjuan: The covid-19 has undergone many mutations, showing that its infectivity and spread have increased, and it has brought huge challenges to the prevention and control of the global pandemic, especially the research and development of vaccines. When the virus mutation site breaks through the neutralizing antibody induced by the covid-19 vaccine, the vaccine’s protective effect will decrease. Although there are international reports that the current vaccine’s protection against mutant viruses has declined, it requires more data and a longer time to test. After all, the covid-19 vaccine has only been on the market for half a year. It has not been possible to systematically evaluate the mutations—the protective effect of the virus.
As far as the current situation is concerned, on the one hand, we need to speed up vaccination so that the population’s vaccination ratio can reach the highest possible level. In this way, the living environment of each family and individual from the country to the community will become even better. On the other hand, scientists have realized the impact of virus mutations on current vaccines. Vaccine research and development institutions have been developing vaccines against mutant viruses. Once the current vaccines are ineffective against mutant viruses or the protection rate has dropped significantly, they can be timely. Replace the original vaccine to ensure the vaccine’s effectiveness.
This wave of the pandemic will not have much impact on China.
P.C. Forum: The flow investigation report shows that the three confirmed cases of the covid-19 virus entering from Chongqing have repeatedly negative nucleic acid tests in India. After returning to China, the chest CT results showed infectious lesions and were diagnosed as covid-19 cases. For the general public, under what circumstances only need to do nucleic acid testing, and under what circumstances need to do nucleic acid testing + chest CT?
Li Lanjuan: The mutation of the covid-19 will affect the sensitivity and accuracy of the detection reagents. If you have lived in a severe pandemic area and the mainstream covid-19 in the pandemic area is a mutated strain, even if you have no symptoms of fever or cough, you must be closely quarantined and observed after returning to your country. In addition to nucleic acid testing, you also need to Do a chest CT scan to determine whether there is an infection in the lungs. For people from common areas, nucleic acid testing is usually sufficient during the isolation and observation period. Therefore, which inspections to be done need to be selected according to the specific situation.
P.C. Forum: Does the aggravation of the pandemic in India and neighboring countries pose a major test for China’s prevention and control capabilities?
Li Lanjuan: The public health prevention and control capacity or level of a country is directly related to whether infectious diseases can be effectively controlled and prevented.
In my opinion, this wave of the pandemic will not have much impact on China because China has always adopted strict prevention and control measures. Various domestic provinces, cities, counties, and even communities have solid prevention and control capabilities. Our coastal defense lines and border defense lines have perfect pandemic prevention measures, including airports, trains, and other transportation fortresses that have strict inspection and isolation measures to ensure The safety of our country and people. However, our country has a large population, a long border, and a high degree of openness. There are often foreigners entering the country. We still need to take good care of the pandemic prevention barrier. We must not relax our vigilance and be indifferent.