With the prolonged outbreak of COVID-19, there is increasing public interest in the Novel Coronavirus situation and containment measures. On February 19, the 94th Pearl River Science Lecture hall was held at guangdong Science Center. Guo Jun, director and doctoral supervisor of State Key Laboratory of Applied Microbiology in South China, was invited to deliver a popular science lecture on the origin of Microbiology and THE prevention and control of COVID-19. In his speech, Guo Jun introduced the development of microbiology from modern times to the present, and from this led to the discussion of novel Coronavirus and the analysis of the trend of COVID-19 epidemic.
Less than 1% of microbes are harmful to humans
What are microbes? Microbe is a general term for all tiny organisms that are difficult to see with the naked eye and require light or electron microscopes, including bacteria (such as lactic acid bacteria, tuberculosis bacillus), viruses (such as rabies virus), fungi (such as Aspergillus aflatus), protozoa (such as green eye worms) and a few algae, Guo said. In addition, some microbes are large enough to be seen with the naked eye, such as large fungi such as mushrooms. Guo noted that microbes are abundant in number and variety, but most of them are harmless to humans. Less than 1% of them are harmful to humans, but almost all infectious diseases are caused by microbes.
Although small in size, microorganisms play a very important role in the circulation of matter in nature. Plants are the synthesizers of matter and the transmutators of matter in the animal world, while microorganisms act as decomposers and cleaners of nature. Some microorganisms also participate in photosynthesis and nitrogen fixation. Without microbes, it could be said, no other life on Earth could survive.
The existence of microbes was not discovered until modern times, guo said. In the mid-17th century, a Dutchman named Leeuwenhoek polished his lens, scraped material from his teeth and put it under the lens. He found microscopic creatures moving. That was how microbes were first observed.
Time came to the 19th century, people explored the relationship between fermentation and microorganism, and found that yeast is a living organism that can cause fermentation. Since then, French scientists Pasteur and German scientists Koch began to study how to use microorganisms to promote production and improve life. Pasteur discovered that the multiplication of microorganisms caused wine to turn sour, and invented Pasteur disinfection method, made an important contribution to the wine industry. Koch invented Koch’s Law, which put forward that many diseases are caused by microorganisms, laying a foundation for the development of later medical career.
In 1928, British Fleming found a sterile circle around penicillium in a petri dish growing staphylococcus bacteria. Rather than ignore his unexpected discovery, he continued his research and eventually invented the first antibiotic, penicillin, or penicillin. For nearly a century, the drug saved countless lives.
In the course of introducing the history of microbiology, Guo jun said that the most important thing for scientific research is interest. Scientific research workers in the interest of the drive, to maintain focus, continue to explore the unknown, to contribute to the development of modern science.
The vaccine helped reduce the number of severe cases
According to Guo jun, novel Coronavirus is a new type of virus, and viruses are an important part of microbial populations. Therefore, the study of novel Coronavirus and pneumonia epidemic is also an important topic of microbiology research.
He said the total number of novel coronavirus infections in the world now exceeds 400 million, including 77 million in the United States. The number of infections increased by 100 million in a single month from January 7 to February 8 this year, thanks to the introduction of a new variant of omicron in November 2021. The five countries with the most cases are the United States, India, Brazil, France and the United Kingdom.
Guo then analyzed why people get infected with COVID-19 even after getting vaccinated. Novel Coronavirus viruses are RNA viruses of respiratory tract infection. They spread rapidly and are prone to mutation. From the human perspective, it takes time for antibody production to peak, and the duration of antibody potency maintenance also needs to be studied.
As for the effectiveness of the vaccine, Guo explained that after three doses of vaccine, the human body produces Igg and IgM antibodies, which play a protective role. Vaccines contribute to the reduction of severe cases, leading to a significant reduction in mortality, which facilitates “dynamic zeroing” and “herd immunity”.
Finally, Guo analyzed the future trends of COVID-19 infection. Guo jun believes that in the future, there is a possibility of a weakened epidemic of novel Coronavirus, which may coexist with humans. However, Omicron is not a large flu, so we cannot downplay the seriousness of the epidemic and weaken the level of attention. Right now, the fatality rate is 2%, lower than SARS and MERS, but the Novel Coronavirus has the greatest impact on humans.
It is thought that the more transmissible the virus is, the less virulent it is and the less virulent it is. But Guo argues that this view is basically impossible to be biologically correct. In addition, COVID-19 can weaken the body’s immunity and cause a variety of sequelae, including mental retardation, bone disease, and internal and vascular problems. Therefore, Guo jun believes that in order to ensure people’s life and health safety, in the absence of a better way to control the epidemic, the “dynamic zero” strategy will not be adjusted for the time being.