In order to give the "panicked" masses a "reassuring pill", today we will give you a detailed introduction.
What is the XBB strain?
Wang Xinyu, Deputy Director of the Department of Infectious Diseases at the National Center for Infectious Disease Research and Huashan Hospital affiliated with Fudan University, stated:
XBB is a sub variant of Omicron, first discovered in India in August 2022 and first named by scientists in September. It is believed to be a "recombination" of two different Omicron variants BA.2.10.1 and BA.2.75 that appeared earlier in 2021.
XBB has further evolved into XBB. 1 and XBB. 1.5, with the latter being a rapidly increasing variant in some European and American countries and already occupying a dominant position in some countries.
But it seems that the symptoms it causes are not particularly severe compared to other variants.
What are the new characteristics of the 02XBB strain?
Xu Wenbo, Director of the Institute of Viral Diseases of the China Center for Disease Control and Prevention, stated that in the past three months, China has detected the introduction of BF.7, BQ.1, and XBB.
BQ.1 and its sub branches were detected in 49 cases in 9 provinces, and XBB sub branches were detected in 11 cases in 3 provinces.
At present, BQ.1 and XBB have not yet formed advantageous dissemination in China, mainly focusing on BA. 5.2 and BF. 7.
The pathogenicity of BQ.1 and XBB strains is not significantly different from other Omicron variant strains, and the severity and mortality rates have not significantly increased, but the transmission and immune escape ability have increased.
Can the 03XBB strain cause secondary infection?
Regarding the issue of reinfection, Lu Hongzhou, President of Shenzhen Third Hospital, stated:
"Although COVID-19 will not be infected within a short period of time, such as three to four months, it is undeniable that the new strain is prevalent or the 'safe window' for secondary infection is shortened.
Therefore, in European and American countries, some people with poor immunity may be infected multiple times within a year
This means that if encountering strains such as XBB, BQ.1, and BQ.1.1, the probability of re infection mainly depends on two aspects:
On the one hand, it is about how much overlap the virus strains encountered again with BA. 5 and BF. 7. If the virus continues to mutate and the cross protection effect decreases, it may cause infection; On the other hand, it depends on the level of human autoantibodies.
Li Dongzeng, the chief physician of the Respiratory and Infectious Diseases Department at Beijing You'an Hospital, stated that reinfection mainly occurs in people with low immunity. People with normal immune function have a relatively low risk of reinfection in a short period of time, and the symptoms after infection are usually milder than those after infection.
What are the symptoms of infection with the 04XBB strain?
According to the Global Initiative for the Sharing of Influenza Data (GISAID), symptoms of infection with the XBB subtype virus include difficulty breathing, headache, sore throat, nasal congestion, systemic pain, fatigue, and fever.