China’s State Drug Administration issued a circular on the 12th approving the listing of five covid-19 antigen self-test products. Wang Daming, a researcher at Suzhou Institute of biomedical engineering technology, Chinese Academy of Sciences, pointed out in an exclusive interview with China News Agency reporters that antigen detection, as a supplementary means, has its application value and can learn from each other.
According to the website of the State Food and drug administration, the application change of covid-19 virus antigen detection kit of Nanjing Nanjing Vazyme Biotech Co.Ltd(688105) , Beijing jinwofu, Shenzhen Huada Yinyuan, Guangzhou Guangzhou Wondfo Biotech Co.Ltd(300482) , Beijing huaketai biology was approved in recent two days. Since then, five covid-19 antigen self-test products have been officially launched.
On the 11th, the comprehensive group of the joint prevention and control mechanism of the State Council announced the application scheme for covid-19 virus antigen detection (Trial), decided to promote the monitoring mode of “antigen screening and nucleic acid diagnosis”, added antigen detection as a supplement to nucleic acid detection, and stipulated three categories of applicable groups for antigen detection, namely:
Those who go to grass-roots medical and health institutions with respiratory tract, fever and other symptoms within 5 days;
Isolation observation personnel, including personnel in home isolation observation, close connection and secondary close connection, entry isolation observation, sealing and control area;
Community residents with antigen self-test needs.
What is the difference between antigen detection and nucleic acid detection? Wang Daming said that the inside of the virus is gene nucleic acid and the outside is a layer of protein. Nucleic acid detection is aimed at the gene of the virus, and antigen detection is aimed at the external protein.
Zhang Wenhong, head of the clinical treatment expert group of covid-19 pneumonia in Shanghai and director of the infection department of Huashan Hospital Affiliated to Fudan University, also said in an interview that antigen detection starts from antibodies to test “clothes”. After comprehensive specificity, the virus can be displayed; Nucleic acid detection is more complex and needs to be completed by amplification. Its sensitivity will be higher, but it will take longer to obtain results.
In addition, the scheme also standardizes the original self-test process and management. Personnel in home isolation observation, close contact and secondary close contact, entry isolation observation, sealed control area and control area shall carry out nucleic acid detection according to the requirements of the current relevant prevention and control plan during the isolation observation period, and conduct antigen self-test once a day in the first five days. Community residents who need self-test can purchase antigen test reagents for self-test through retail pharmacies, online sales platforms and other channels.
At the same time, Chinese officials also issued the basic requirements and procedures for covid-19 virus antigen self-test to standardize the basic requirements and operation procedures of the original self-test. When conducting antigen detection, isolation observers and community residents shall carefully read the instructions and standardize the operation to ensure the accuracy of the results.
Wang Daming believes that whether the self-test can be standardized and accurate depends on two aspects: one is the use and design of the product, and the other is the difficulty of user acceptance. The operation of the test kit itself is not complex, which is the basis for the public to use for their own use. The instruction manual is also generally based on diagrams, which is convenient for users to understand and operate according to the same.
It should be pointed out that as a supplementary means, antigen detection can be used for screening of specific populations, which is conducive to improving the ability of “early detection”, but nucleic acid detection is still the basis for the diagnosis of covid-19 virus infection. Once the antigen test is positive, it shall be reported to the relevant departments immediately; If necessary, conduct nucleic acid test for confirmation.
The “plan” issued this time has also formulated the disposal management process after the detection is found to be positive, so as to promote the connection between antigen detection and nucleic acid detection. For example, for those who are positive for antigen testing, the grass-roots medical and health institutions should immediately report to the disease control department under their jurisdiction, and the emergency center will transfer the antigen positive personnel to the medical institutions with fever clinics for nuclear acid testing in accordance with covid-19 guidelines for the transfer of personnel related to the pneumonia epidemic.
“In fact, the relevant regulations are very clear.” Wang Daming believes that the application of antigen detection and the management of “antigen positive personnel” in the future need to be further integrated with the current prevention and control measures.
The expert pointed out that as one of the means of infectious disease prevention and control, antigen detection has been mature in the prevention and control of influenza and other infectious diseases. Covid-19 virus antigen detection, as an auxiliary means, has its application value. Considering the transmission characteristics of Omicron, it is a good thing to have another means of prevention and control. Antigen detection is currently used as a primary screening measure for covid-19 virus infection. It can be used in combination with nucleic acid detection, which can learn from each other.
