Chinese CDC expert: Virus mutation poses a challenge to herd immunity and we must not let down our guard

People's Daily Online, Beijing, September 16 (Reporter Sun Hongli) The Joint Prevention and Control Mechanism of the State Council held a press conference on the 16th to introduce the situation of further epidemic prevention and control and vaccination. Wang Huaqing, chief expert of the immunization program of the Chinese Center for Disease Control and Prevention, said that the full vaccination of more than 1 billion people in my country has laid a certain foundation for controlling the spread of the new crown epidemic. In addition, the mutation of the new coronavirus has brought certain challenges to the establishment of herd immunity, and vigilance cannot be relaxed at present.

Wang Huaqing pointed out that the more people are vaccinated, the greater the protective effect of the vaccine. From an individual perspective, COVID-19 vaccination can prevent infection and disease, and the more significant effect is to prevent severe illness and death after infection. From a group perspective, based on past experience, if the vaccination rate is high, the vaccine will be more effective. "Of course, there is also a special situation now, that is, the mutation of the new coronavirus. The Delta virus variant is very contagious, and we have also seen a weakening of the protective efficacy in some vaccines, which has brought certain challenges to our establishment of herd immunity."

Wang Huaqing said that in order to face this challenge in the future, it is necessary to strengthen virus monitoring, disease monitoring, and vaccine effectiveness evaluation. We must also continuously improve the immunization strategy of the new crown vaccine and further develop better vaccines to prevent related diseases.

"We cannot relax our vigilance at this moment." Wang Huaqing stressed that, on the one hand, the Delta virus variant is highly contagious; on the other hand, some elderly and young people have not yet completed vaccination. It is recommended that those who meet the vaccination conditions be vaccinated as soon as possible. Only when more people are vaccinated can the vaccine really work. People under the age of 12 who have not yet been vaccinated should also be considered for vaccination.

In addition, regarding the public's refusal to take the COVID-19 vaccine due to concerns about serious adverse reactions, Wang Huaqing said that judging from the results of the vaccine's early clinical trials and real-world applications, the vaccine is effective, including preventing infection, especially preventing severe illness and avoiding death. In this case, vaccination becomes even more important.

"Overall, whether it is an inactivated vaccine or a protein subunit vaccine, judging from the results of clinical trials and subsequent monitoring, the adverse reactions to vaccination are basically similar to those of previously routinely used vaccines. Of course, we will also strengthen the monitoring and analysis of adverse reactions to vaccines in the future," said Wang Huaqing.