From January 13 to 16, local Omicron positive cases were reported in Zhongshan, Zhuhai, Shenzhen and Meizhou of Guangdong Province. On January 15, a newly confirmed local case in Beijing was confirmed to be infected with Omicron mutant. According to the official notification of the joint prevention and control mechanism of the State Council, China is facing the dual challenge of the import of delta and Omicron strains. According to incomplete statistics, the Omicron mutant has spread to at least 173 countries or regions. Will Omicron be more powerful than Delta? Is the vaccine still useful? On January 17, Lin Peng, chief scientist of Guangdong CDC, answered these questions of public concern one by one. The load of Omicron virus is higher Nanfang Daily: will the transmission power of Omicron mutant be stronger than that of Delta? Lin Peng: the load of Omicron virus is higher and the transmission power is enhanced. The research team of the school of medicine of the University of Hong Kong found that the viral load of Omicron in human bronchial tissue was nearly 70 times higher than that of delta 24 hours after infection. Therefore, Omicron also has the characteristics of faster replication speed and stronger replication ability. On December 23, 2021, the cohort analysis data released by the British health and Safety Bureau showed that the risk of infection of close contacts caused by Omicron mutant infection was significantly higher than that of delta mutant infection, whether in the family environment or outside the family environment. Nanfang Daily: what are the main symptoms of infection with Omicron mutant? Is there a high risk of severe illness? Lin Peng: after infection with Omicron, it is mainly mild disease. Due to the time lag from onset to severe and death, the clinical severity caused by Omicron still needs more data to be proved. Up to now, the vast majority of infected people have only mild or asymptomatic symptoms, few severe cases and few deaths. The main symptoms include influenza like symptoms such as cough, fatigue, nasal congestion, runny nose, drowsiness, headache, sore throat and fever. Researchers from South Africa, Britain and other countries found that the risk of severe illness of Omicron infected persons was lower than that of non Omicron infected persons and early delta infected persons in the same period. Although studies have shown that the virulence of the Omicron mutant is weakened, the heads of who, CDC and other institutions said that the high transmissibility of the Omicron mutant can increase the number of cases and may still defeat the health system. Nanfang Daily: there is immune escape in Omicron. Can the new crown vaccine we use prevent Omicron? Lin Peng: Yes. The study found that Omicron had a significant escape from previous infection and humoral immunity induced by vaccination, but the whole process vaccination can still protect people from severe diseases to a great extent. Domestic inactivated vaccine is still effective. Another U.S. study shows that cellular immunity is not affected by Omicron, and enhanced vaccination, especially heterologous enhanced vaccination, such as inactivated virus vaccine + recombinant protein subunit vaccine or mRNA vaccine, can significantly improve the titer of neutralizing antibody in human body. Studies have shown that the development of Pan coronavirus vaccine may be the focus of research and development of COVID-19 vaccine in the future. Cross provincial floating personnel arrive in Guangdong to measure nucleic acid in time Nanfang Daily: how should we take precautions during the Spring Festival? Lin Peng: after arriving in Guangdong Province across the province, we should complete a COVID-19 nucleic acid test in time and strengthen self health monitoring. In case of acute symptoms such as fever, cough, sore throat, decreased sense of smell (taste), or the health code changes to "yellow code", do not buy drugs by yourself. Conduct a nucleic acid test immediately and seek medical treatment. Do not travel until the risk of infection is eliminated. People aged 18 and above and 6 months after completing the whole process of vaccination should be vaccinated with booster needles as soon as possible to obtain the best protection. Recently, the new crown vaccine inventory in our province is sufficient, and those who have not completed the whole process or strengthened immunization can be vaccinated actively. (Xinhua News Agency)