Moreover, the emergence of this second infection case will also inspire the research of vaccine. In this regard, the team of the Department of Microbiology of HKU suggested that people who have recovered should continue to maintain their awareness of epidemic prevention and consider taking COVID-19 vaccine in the future.
It is reported that this man was diagnosed with COVID-19 virus in March this year. At that time, he developed symptoms such as cough and fever, and was discharged from hospital in mid-April after treatment. He went to Spain via England in August, and was diagnosed again after arriving in Hong Kong on May 5438+05, but he was asymptomatic this time. He was discharged on August 2 1 after receiving treatment.
The research team of the Department of Microbiology, School of Medicine, Hong Kong University found that the gene sequencing results of the virus strains infected by the man twice were obviously different, and through the comparison of the virus gene pool, it was found that the virus infected for the first time was similar to the virus strains in the United States and Britain in March and April, and the virus infected for the second time was similar to the virus strains in Britain and Switzerland in July and August.
The research team found that when the patient was infected for the second time, the antibody was not detected at the initial stage of hospitalization until the fifth day of hospitalization. One of the reasons may be that he did not produce antibodies in his body when he was infected with the virus for the first time, or that the antibodies produced by the patient after the first infection gradually decreased with time, so no antibodies were detected in the initial stage after the second infection.
Extended data:
COVID-19 has made rapid progress in vaccine research and development.
It is understood that as of August 20th, COVID-19 has covered more than 200 countries and regions around the world, and COVID-19 reported 22.25 million cases and more than 780,000 deaths. Wang Huaqing, chief expert of immunization program of China CDC, said that based on the containment strategy adopted in the early stage, especially the drug prevention strategy, China has achieved remarkable results in the epidemic prevention stage, but the epidemic situation has not been contained in other countries, so people still pin their hopes on vaccine research and development.
Wang Huaqing said, "This is a new infectious disease, and its etiology, clinic, epidemiology and vaccinology are still being understood. Although there are so many technical routes and vaccines being studied at present, it is still unknown who will end up in the end. However, for dealing with epidemic infectious diseases, this will increase the chances of successfully developing vaccines and provide more choices for using vaccines in the future. "
The effectiveness and safety of vaccines used in the study of emerging infectious diseases have always been concerned. Wang Huaqing said that regarding the effectiveness, the minimum protection rate of vaccines at present is 50%. There is also a lower limit requirement for the protection durability of vaccines. Generally speaking, it needs more than 1 year, and the shortest protection period of vaccine shall not be less than half a year.
The research and development of vaccines in COVID-19 has made rapid progress, and 29 vaccines have entered clinical trials.
China Economic Net-HKU confirmed that the world's first rehabilitated person was infected with COVID-19 for the second time.