Antibody tests have caught the world's attention because they have the potential to help identify asymptomatic versus mild infections by revealing who has been exposed to the new coronavirus and may now be immune. outbreak of the epidemic.

novel coronavirus

1. Some people support the role of the new coronavirus antibody test

Dozens of biotech companies and research labs have rushed to produce blood tests. Governments around the world have purchased millions of test kits in the hope that they will guide decisions about when to ease social distancing measures and allow people to return to work. Some have even suggested that the tests could serve as an "immunity passport" that would allow people with an "immunity passport" to interact with others again.

Some researchers say the tests could tell health care and other essential workers if they are still at risk of infection. In the future, they could also assess whether vaccine candidates immunize people.

2. Some people think that the role of the new coronavirus antibody test is exaggerated

Don't think you'll be fine after a new coronavirus antibody test

But as with most new technologies, there are signs that the role of COVID-19 antibody tests has been overstated, and most kits are currently not accurate enough to confirm whether a person has been exposed to the virus. Some scientists say that even reliable test results do not indicate whether someone is immune to reinfection.

3. What can the new coronavirus antibody test do?

Researchers around the world are also using antibody tests to estimate how infectious the coronavirus is at the population level, given that insufficient standard testing is being done in many places, and people with mild or no symptoms are likely to be caught in official case counts. Missed, this is very valuable. These surveys test a subset of the population and use that to estimate infections in the wider community.

When a virus invades the body, the immune system produces antibodies to fight it. The kit detects the presence of antibodies using antigenic components in the virus. Tests generally fall into two categories: laboratory tests, which are handled by trained technicians and take about a day, and isolated point tests, which give quick field results in 15 minutes to half an hour. The tests did not detect the virus itself, the health agency said, so have limited application in diagnosing active infections.

Fourth, the results of the new coronavirus antibody test need to be interpreted with caution

Early studies of people who have recovered from COVID-19 have detected three SARS-CoV-2-specific antibodies, and manufacturers and research institutions have developed assays for these antibodies. For example, some biopharmaceutical companies have developed a laboratory test to detect SARS-CoV-2-specific immunoglobulin G and immunoglobulin a.

Don't think you'll be fine after a new coronavirus antibody test

Many of the tests available now appear to be inaccurate enough to identify people with the disease, a property called test sensitivity and those who are not infected called test specificity. A high-quality test should have a sensitivity and specificity of 99% or more, which means that for every 100 true positive and true negative results, the test should have only 1 false positive and 1 false negative.

But some antibody tests have specificity as low as 40 percent early in infection. In 2 of the 9 tests analyzed, the sensitivity of 3 laboratory tests was between 67-93% and the specificity was between 93-100%. Overall, the sensitivity of all tests improved over time, with the highest sensitivity recorded two weeks after symptoms first appeared.

Convenient and quick tests are even less reliable than those used in the lab. That's because they use smaller blood samples -- usually referring to stab blood samples -- and do it in a more uncontrolled environment than a lab, which can affect their performance. They should be used with caution, and the WHO recommends that point-of-care testing be used for research only.

An unknown factor affecting both tests is the interaction between time and accuracy. If a person is tested too soon after being infected, and the body has not had time to produce the antibodies that the test is for, it could miss the infection. However, scientists do not yet know the timing of the body's immune response to SARS-CoV-2, and cannot say exactly when specific antibodies are produced.

In summary, after completing the new coronavirus antibody test, the results should be carefully analyzed, and the most important thing is the contact history. For suspicious manifestations, multiple tests are required to achieve the real purpose.