A Combination Of Tests Key To Preventing COVID-19 Flare-Ups After Isolation Ends

Speaker 1: 00:00 Officials around the country are starting to release timelines for when people can start to end their isolation. KPBS science and technology reporter Shalina Chet Lani says, robust testing is necessary to prevent another surge in cases, but it may not be a catchall solution Speaker 2: 00:17 for most people. Facing a pandemic is a new experience, but for California, there's a familiarity with this crisis because it's similar to how we deal with fire season. So Summa Chanda Speaker 3: 00:28 fire season rolls around, you see these brush fires SDG and E and the fire departments are just surveying the back country and as soon as one of these flares up, they bring in the cavalry and they, they tamp that down. Speaker 2: 00:41 Shunda a virologist at the Sanford Burnham previs medical discovery Institute says, without herd immunity, it's impossible to prevent these flareups from happening. Herd immunity occurs when enough people have become infected to develop antibodies that can fend off the virus, or there's a vaccine so that people can become immune Speaker 3: 00:59 herd immunities, like clearing your backyard of brushes. Every person that has antibodies to the virus, either through the vaccine or being infected previously. Those are people that can no longer burn. Speaker 2: 01:10 Social distancing has slowed down the rate of infections, but the problem is society has to open back up and there's still no herd immunity since the vaccine will be developed for months to over a year. Churn to says vigorous testing is necessary now and especially when isolation ends. Speaker 3: 01:28 Either you're Superman for the lent next year when it comes to coven or you're a potential Barsch Brushfire and you need to be contained as quickly as possible. Those are the two pieces of information that those tests tell you. Speaker 2: 01:42 Trinda is referring to two main tests. The first is a PCR or preliminary chain reaction test. David pride, a pathologist at UC San Diego says this test is used to detect a number of viruses, which are Speaker 4: 01:54 basically like little organisms. So really these tests are all about just taking a tiny amount, um, and making a large amount so that it's easy to see. Speaker 2: 02:04 PCR tests take genetic material like RNA from cells collected on swabs. Scientists sort of magnify these samples to detect trace amounts of the virus. Faster point of care tests with advanced instrumentation can deliver results in less than an hour, but PCR tests only diagnose whether someone has the virus now, not whether they had it in the past. That's where a blood test comes in. These can detect antibodies which shows that a person got infected in the past and were able to fight the infection off. Speaker 4: 02:34 We're not really trying to detect the virus in your blood. What we're trying to detect is your body's response to the virus, uh, and your blood Speaker 2: 02:44 pride says these tests are important to show which people might be less vulnerable or less likely to spread the virus when they go back to work. It also means people who are immune may be able to donate their antibodies to people who aren't. Speaker 4: 02:57 Those are things that have been done for other infections in the past. Like Ebola Speaker 2: 03:01 pride says a combination of these tests is key to maintaining coronavirus. PCR tests will show who's infected. It needs to be quarantine. Well, blood tests show which people are less susceptible, but there's another factor that's necessary for these measures to keep fires from starting. And that's public participation. So as Michael Bush, director of the blood donation company violent, Speaker 4: 03:22 okay, we want to test the 300 million people in this country. You've got to get all those people sampled, you've got to get them to go into a laboratory or a clinic setting where they have their blood drawn. Speaker 2: 03:34 Blood bank networks are built to more easily get samples from people and process them. Cova testing doesn't have that network and early evidence from South Korea shows some people can get infected twice. So Bush says, well, mass testing can squash a lot of flareups. It won't prevent all of them. Speaker 4: 03:51 There'll be a dance, there'll be ongoing, both public health and individual testing going on [inaudible] and that'll continue. Speaker 2: 03:58 And Bush says it will take a while before the world returns to what was [inaudible]. Speaker 4: 04:03 It will not be as if all of a sudden we test everybody and the parties over the dance will go on for the next several years until we have an effective vaccine. Speaker 2: 04:13 Until then he says there'll all have to be active public participation alongside testing. That means lots of hand-washing, limited public gatherings and the need for people to monitor their symptoms. Shelina Celani K PBS news.