Gently break the finger, take a drop of blood, drop in the test card sample hole and drip with dilution, 15 minutes later can be by observing the reaction line appear or not, to determine whether they have been infected with the new coronavirus. Similar to the widely used HIV testing kit principle, this new coronavirus antibody rapid detection kit has recently become a popular choice for multi-country outbreak prevention and control.
Determine the true “penetration” of the virus
Referring to the new coronavirus testing, people are most familiar with the current as a diagnostic “gold standard” nucleic acid testing. Nucleic acid testing is a “on-the-go” test that detects specific nucleic acid sequences in the virus genome through polymerase chain reactions to determine whether the subject is currently infected with a virus.
Antibody testing is “past time” test, the human body infected with the virus will produce IgM or IgG antibodies, detection of these specific antibodies in the serum, can determine whether the subject has been infected with the virus.
Nucleic acid detection has great limitations. The new coronavirus mainly infects the lower respiratory tract, while the current widespread nasopharyngeal swab sampling is sometimes difficult to detect the virus, coupled with the sensitivity of the reagent itself, has been reported in many countries nucleic acid testing “false negative” patients. Antibody testing can be complemented with nucleic acid testing to improve diagnostic effectiveness, especially for better screening of asymptomatic patients.
The new coronavirus is very “sophisticated”, the nucleic acid detection of hidden cases can interfere with the assessment of the outbreak and prevention and control measures. “Antibody detection can help determine the true ‘penetration’ of the new coronavirus in the population and is important to understand the true infection capacity of the virus. He Dayi, a professor at Columbia University School of Medicine in the United States, said.
Preliminary research suggests that new coronary recessive cases may account for about 60 percent of all infections, the British journal Nature reported. After asymptomatic and light patients heal, there will still be IgG antibodies in the body, through serum antibody testing can identify these infected people.
The UK could become the first country to conduct large-scale antibody testing. The British government has ordered 3.5 million new coronavirus antibody testing kits for distribution to home isolationists, followed by millions more for first-line workers and on pharmacies and e-commerce platforms, the Guardian reported. British government officials say antibody testing could help researchers better understand how the virus is spreading by determining who has contracted the new coronavirus and produced antibodies, regardless of whether or not they develop symptoms.
The Spanish government also plans to conduct antibody testing in hospitals, homes for the elderly and other places at higher risk of infection.
Australia’s health department has said it plans to test 15 million people for antibodies. Larissa Labouo, a researcher at the Institute of Molecular Biosciences at the University of Queensland in Australia, said antibody testing was an important way to track the true state of the outbreak. But it takes a week or more for the immune system to produce antibodies, and only nucleic acids and antibodies can be used to more accurately determine the infection.
Preparing for the “exit” of epidemic prevention and control
Many countries to increase the detection of new coronavirus antibodies, another goal is to identify people who are already immune to the virus, in preparation for the future outbreak prevention and control “exit” strategy.
Jean-Francois de Fress, president of the French Scientific Council and a former president of the French Medical Ethics Commission, said france plans to test most of the population for antibodies, up to 200,000 to 300,000 a day. The test results will be used to evaluate the lifting of the city and to implement targeted isolation measures, and to develop a follow-up “exit” strategy.
“The immunity group is a ‘firewall’ group,” Professor Chen Baoquan, executive director of the Center for Cutting Computing At Large, told reporters. “
In the view of many experts, through antibody detection to identify the population who have been immune, will also provide the basis for the follow-up fine isolation, lifting of the city and other preventive and control measures.
Researchers at the Helmholtz Center for Infectious Diseases in Germany said they plan to first distribute 100,000 antibody test kits to the German public in early April, and that those who test positive for antibodies will be given an “immune certificate” that can be lifted early. Researchers say a large number of antibody tests will help the government determine which areas have been “group immunized” to lift the blockade.
Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, told CBS News Tuesday that deciding when to lift the city, quarantine, etc., is to look at the epidemic curve, and then to conduct simpler and cheaper antibody testing to determine whether the population is immunized.
Larissa believes that because antibody testing is faster than vaccines, it could also guide vaccine development. Before the vaccine is successfully developed, antibody testing can help scientists and health authorities understand who is infected, who has recovered, how much risk we are at risk of being re-infected, and so on.
The new coronavirus antibody testing using colloidal gold method, this technology has been used in AIDS and other disease detection for 20 years. A number of companies in China and the United States are able to produce rapid detection kits for new coronavirus antibodies, but only a few companies are currently registered to produce them, which cannot be compared with the large number of nucleic acid reagents. Experts believe that more attention should be paid to antibody testing.
Xinhua News Agency, Beijing, April 9 News Analysis: Why antibody testing of new coronavirus is becoming more and more important
Xinhua News Agency reporter Peng Xi Yalin