美国有线新闻 CNN 什么是新冠病毒抗体检测?（在线收听）

More than 1.8 million people worldwide have contracted COVID-19. Most people who get the disease will recover. So the next question for them is are they now immune to coronavirus and for how long?

REPORTER: According to the Coronavirus Task Force, more than 2 million tests have now been performed in the United States. And yet there are still people who need to be tested, such as healthcare workers who can't get one. It's part of the reason there is now so much interest in a different kind of test — an antibody test. Dr. Fauci told CNN on Friday, it's coming soon.

DR. ANTHONY FAUCI: I'm certain that that's going to happen that within a period of a week or so we're going to have a rather large number of tests that are available.

REPORTER: But what exactly are antibodies? They are proteins in the immune system that develop days after someone has been infected. And it's the antibodies that make someone immune to becoming re-infected. It means two things — you were previously infected and you are now likely to be protected, at least for a while.

DR. STEPHEN HAHN: We think it will be a tool that will help us get people back to work. It will be additional information because as you know, if you have an antibody that means you were exposed and have recovered from it. That with the information about diagnosis should help.

REPORTER: That's why public health agencies around the world want these antibody tests because it could help some people get back to their daily lives. You remember the swab test we're all familiar with — well that tests for the virus itself, specifically its genetic material. Problems are first of all at some point after you recover, that test will be negative. And secondly, a lot of people have had trouble getting that diagnostic test in the first place.

The antibody test is more definitive. There are only a few reasons you would have antibodies in your blood. You got someone else's antibodies by an injection of their blood; you got a vaccine which teaches your body to make antibodies; or you were infected. The antibody test requires a sample of your blood and this strip which has proteins from the virus on it. If your blood reacts to that strip, it means you have antibodies in your blood.

DR. DEBORAH BIRX: And I think really being able to tell them, the peace of mind that would come from knowing you already were infected, you have the antibody, you're safe from re-infection, 99.9% of the time. And so this, I think would be very reassuring to our frontline healthcare workers.

REPORTER: Another benefit of antibody testing —surveillance. In places like Miami-Dade County, Florida, Santa Clara County, California and Telluride, Colorado, they have already starting using antibody tests to get a better sense of how many people, many of whom will be surprised to learn have already been exposed to the virus.