The epidemic in Shanghai remains high. Anti-epidemic expert Zhang Wenhong said that the Omicron subtype variant BA.2 is currently prevalent in Shanghai. One person can infect 10 people, and the transmission intensity is 3 to 5 times that of the initial stage of the epidemic in 2020; however, Shanghai The “exponential rise” of the epidemic has been interrupted.
The local COVID-19 epidemic in Shanghai has entered its third week. At the press conference on epidemic prevention and control on the morning of the 25th, a reporter asked why the number of infections remained high? Zhang Wenhong, director of the Department of Infectious Diseases at Shanghai Huashan Hospital, said that the virus is constantly mutating, and the second generation of Omicron virus variants has emerged.
He said that the Omicron subtype variant BA.2 is currently circulating in Shanghai, and the R0 value of the transmission strength is 9.5, that is, one person can infect 10 people following infection; while the R0 value of the virus in the early stage of the epidemic in 2020 is between 2.5 and 3. The spread of the virus is now almost three to five times stronger than it was in the early days.
He said that the incubation period of the virus has also been shortened. Basically, it can be passed on to one generation in 3 days, and it may infect 1,000 people in 10 days, which is an exponential increase.
Zhang Wenhong said that from the perspective of Shanghai’s current prevention and control strategy, although the number of cases is still rising, “the entire exponential rise in transmission has been interrupted”; in rolling screening, the proportion of non-controlled areas that are screened positive It has continued to decline, and the current positive rate is regarding 10%.
He said that if the proportion of positive screenings in non-lockdown areas continues to decline, the epidemic will soon reverse downwards.
He said that the current situation is still very serious, “it will not take a long time for no country to defeat this virus”. Recent experience in Hong Kong shows that the third dose of the vaccine can effectively reduce the severe disease rate and case fatality rate.
