So said Zhong Nanshan, an academician of the Chinese Academy of Engineering, when he attended the 2021 graduation ceremony of the University of Science and Technology of Shanghai in Shanghai on July 3. Zhong Nanshan said that

China's whole virus inactivated vaccine, the rate of protection against infection, pneumonia and severe disease are effective, so rest assured that the injection of domestic vaccine is effective against all Delta variant strains.

Guangzhou experience: 153 cases vs. more than 7.3 million

In the current round of the outbreak, a total of 153 infections were reported in Guangzhou with the new crown nucleic acid rapid test. Zhong Nanshan said, "If we hadn't done that, Guangzhou would have had more than 7.3 million people infected in the last 20 days if we hadn't taken prevention and control seriously and tracked it precisely, as a result of the (epidemic scale mathematical) model. This gives us some experience and lessons."

Combined with the characteristics of Delta variant infection cases observed from the clinical end by Prof. Cai Weiping, chief expert of the Infectious Disease Center of Guangzhou Eighth People's Hospital, from the epidemiological point of view, Delta variant has the following 6 characteristics compared to the 2020 epidemic strain.

In the face of the widespread spread of Delta variant strains worldwide, how should we do a good job in the prevention and control of Delta variant strains?

Figure: Core measures to prevent and control COVID-19 in China

The three main elements of the infectious disease prevention and control strategy: discovering the source of infection, cutting off the transmission route, and protecting the susceptible population.

1、Rapid nucleic acid testing of new coronavirus remains a powerful tool for outbreak prevention and control

The source of infection of New Coronavirus is mainly confirmed cases of New Coronavirus pneumonia and asymptomatic infected persons, and the main transmission route is through respiratory droplets and close contact transmission. Through rapid nucleic acid testing, the source of infection can be detected in a timely manner, and close contacts can be traced to quickly cut off the chain of epidemic transmission.

2、Gene sequencing is an important tool for virus epidemic strain monitoring

Genetic sequencing of viruses by CDC agencies for outbreaks and imported cases from abroad can effectively monitor virus mutation and epidemiology, which is an important link in the epidemic prevention and control system.

3. Vaccination is the most economical and rapid preventive and control measure

The population is generally susceptible to the new coronavirus. By establishing a herd immunity barrier through vaccination, the population will become immune to the virus and the virus will not be able to continue to spread down the line.

As the epidemic continues and the virus continues to spread, mutations of the virus will accumulate. In the face of an epidemic of mutated strains, we need to strengthen prevention and control measures on all fronts: more frequent rapid testing of new coronary nucleic acids, accelerated epidemiological investigations, and faster vaccination.

Delta mutant strains" are too cunning, and precise prevention and control is especially important!