From January 13th to 16th, Guangdong Zhongshan, Zhuhai, Shenzhen and Meizhou successively reported local Omicron positive cases.

On January 15, Beijing added 1 new local confirmed case, which was confirmed to be infected with the Omicron variant.

  According to the official report of the Joint Prevention and Control Mechanism of the State Council, my country is facing the dual challenge of imported epidemics of Delta and Omicron strains.

According to incomplete statistics, the Omicron variant has now spread to at least 173 countries/regions.

What is Omicron?

Will it have higher transmission power than delta?

Do vaccines still work?

On January 17, Lin Peng, chief scientist of the Guangdong Provincial Center for Disease Control and Prevention, answered the above questions.

1. What is the difference between Omicron and other mutants?

  Lin Peng: The Omicron variant was first detected in South Africa on November 9, 2021, and the World Health Organization classified it as a Variants Under Monitoring on November 24. VUM), which was upgraded to be classified as Variants of Concern (VOC) on November 26.

On January 11, 2022, the World Health Organization announced that Omicron has replaced Delta as the dominant strain worldwide.

  Compared with the other four VOC mutants (Alpha, Beta, Gamma, Delta), the Ormicron mutant has more spike protein mutation sites, and some of the mutation sites are shared with these four VOCs. The loci have been shown to be associated with enhanced cellular receptor affinity, viral replication and immune evasion.

The influence of some new mutation sites in Omicron needs further study.

2. Compared with Delta, will the Omicron variant spread more powerfully?

  Lin Peng: Omicron has a higher viral load and enhanced transmission.

The research team from the Faculty of Medicine at the University of Hong Kong found that 24 hours after infection, Omicron had a nearly 70-fold higher viral load in human bronchial tissue than delta.

Therefore, Omicron also has the characteristics of faster replication and stronger replication.

  On December 23, 2021, the cohort analysis data released by the UK Health Security Agency showed that the family recurrence rate of Omicron variant infection was 13.6%, and the out-of-home recurrence rate was 7.6%; while the delta variant infection rate was 7.6%. The family recurrence rate was 10.1% and the non-family recurrence rate was 2.8%; the risk of infection among close contacts of people infected with the Omicron variant was significantly higher than that of Delta, whether in the home environment or outside the home environment mutated strains.

3. What are the main symptoms of infection with the Omicron variant?

Is there a high risk of severe illness?

  Lin Peng: Mild symptoms are the main symptoms after infection.

Due to the time lag from onset to severe/death, the clinical severity of Omicron remains to be confirmed by more data.

Up to now, the vast majority of infected people have only shown mild symptoms or no symptoms, with fewer severe cases and very few deaths. The main symptoms include cough, fatigue, nasal congestion, runny nose, lethargy, headache, sore throat, fever and other flu-like symptoms symptom.

  Researchers in South Africa, the United Kingdom and other countries have found that Omicron-infected patients have a lower risk of severe illness than non-Omicoron-infected and early Delta-infected patients during the same period.

For example, on December 28, 2021, researchers in South Africa published a study showing that people infected with Omicron mutated strains were infected with Omicron mutans compared with non-Omicron mutated individuals before this outbreak. Compared with the non-Omicron variant infected patients before this round of epidemic, the death rate of the former was 4.5% and the latter was 21.3%; the ICU admission rate was 1% and the latter was 4.3%; the length of hospitalization was 4.3%. 4.0 days, the latter was 8.8 days; the proportion of inpatients requiring oxygen supply was 45% for the former and 99.5% for the latter; only one third of those infected with the Omicron variant had pneumonia symptoms, of which 72% For mild to moderate disease.

  Although studies have shown that the virulence of the Omicron variant is weakened, the heads of the WHO and the US Centers for Disease Control and Prevention have said that the highly transmissible Omicron variant can cause a surge in the number of cases and may still overwhelm the health system.

4. Omikron has immune escape. Can the new crown vaccine we use at present still prevent Omikron?

  Lin Peng: Yes.

The study found that Omicron has significant escape from previous infection and vaccination-induced humoral immunity, but full-course vaccination can still largely protect people from severe illness.

Domestic inactivated vaccines are still effective.

  Another American study showed that cellular immunity is not greatly affected by Omicron, and booster vaccination, especially heterologous booster vaccination, such as inactivated virus vaccine + recombinant protein subunit vaccine/mRNA vaccine, can significantly improve the human body. and antibody titers.

Some studies have shown that the research and development of pan-coronavirus vaccines may be the key research and development direction of new coronavirus vaccines in the future.

5. During the Spring Festival, how should we take precautions?

  Lin Peng: After arriving in Guangdong, inter-provincial migrants should complete a nucleic acid test for the new coronavirus in time, and strengthen self-health monitoring.

If you have acute symptoms such as fever, cough, sore throat, decreased sense of smell (taste), or the health code changes to "yellow code", do not buy medicines by yourself, you should immediately carry out a nucleic acid test and seek medical attention. If the risk of infection has not been ruled out Do not travel before.

  If you have the "top ten symptoms" of new coronary pneumonia, please take a nucleic acid test in time.

People who are 18 years old and above and 6 months after completing the whole vaccination should get the booster shot as soon as possible to get the best protection.

  Recently, the stock of new crown vaccines in Guangdong Province is sufficient, and those who have not completed the full course or booster immunization can be actively vaccinated.

Citizens can check the vaccination information on Yuekang Code, Yuejiantong WeChat applet or Yuemiao App. If they meet the requirements for booster immunization, they can make an appointment as soon as possible through the locally announced appointment channel, or go directly to the nearest vaccination point for booster. Needle vaccination.

  (Headquarters reporter Chen Xuting)

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