Foreign media analysis: novel coronavirus pneumonia after 7 months of science has known and unknown

It has been more than seven months since the world’s first case of new coronavirus infection was confirmed, foreign media said. We have learned a lot during this period, but the scientific community has not answered some key questions. This is because it is a new virus, so there is no previously developed immunity in the population. The virus is spread by droplets and contact. The disease it causes has a period of several days. The affected people may or may not have symptoms, but they all have the ability to transmit. Ignacio Lopez GONI, a professor of Microbiology at the University of Navarra in Spain, concluded: “this is the worst nightmare for epidemiologists trying to control this pandemic.” According to the report, advanced technology and international scientific cooperation enable people to quickly understand the “identity” of the virus. The first AIDS cases were recorded in 1980, but it took years to discover the pathogen HIV. Now, in just a few days, the first batch of new coronavirus cases were discovered, which was hidden behind the coronavirus sars-cov-2. Obtaining its complete genome enables researchers to analyze its source, animal host, development process and relationship with other coronaviruses, and introduce molecular detection systems, such as nucleic acid detection, which is now well known. For vaccine development, it is good news that the new coronavirus will not mutate quickly. These vaccine projects are based on the sequencing of sars-cov-2 genes, so significant changes in their genes may affect the effectiveness of the vaccine. According to the report, scientific research has also tried to find out the main transmission mode of the new coronavirus: when coughing, sneezing or talking loudly, it spreads through droplets within two meters. It is not known how many viruses can cause infection, but in a closed space with many people and close contact for a long time, the situation will always be worse. < / P > < p > it is well known that there are some “highly contagious” people and activities. Wearing masks, frequent hand washing and keeping social distance are important parts of protective measures. There is no dispute about the spread of aerosols. However, the distance and duration of aerosol propagation are not clear. Recently, a preliminary study by the University of Florida found that the spread distance of the new coronavirus on aerosols is within 5 meters, which is much larger than the recommended 2 meters of social distance measures. One of the unknowns that the scientific community is still studying is why many infected people have no symptoms, according to the report. Studies have shown that this part of the infected people account for about 20%. Possible causes that have been proposed include rapid immune response; pre immune response triggered by cross reaction with other coronaviruses; genetic factors; and very low number of viruses at the time of infection. The novel coronavirus pneumonia has been studied by

. Children have not yet developed the immune system because of their immature immune system. This kind of “storm” seems to be one of the factors contributing to the recurrence of pneumonia. < / P > < p > it is also unclear how long reinfection and immunization can last. Following a follow-up study of 349 symptomatic patients, Chinese scientists found that 70% of the patients remained neutralizing antibodies for at least six months. For healthy people, some studies have indicated that some people may have immune cells capable of recognizing sars-cov-2 virus, which may be due to previous infection with other coronaviruses, although this possible cross reactivity has not been confirmed. 08/17/2020