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An announcement from the White House could expand rapid COVID-19 testing significantly as President Trump boasts about U.S. testing capacity. Harvard epidemiologist Dr. Michael Mina lays out the testing failures so far and how rapid tests could help get our lives back to normal in the pandemic.
Dr. Michael Mina, assistant professor of epidemiology and assistant professor of immunology and infectious diseases at the Harvard T. H. Chan School of Public Health. Associate medical director in clinical microbiology at Brigham and Women’s Hospital, Harvard Medical School. Core member of the Center for Communicable Disease Dynamics. (@michaelmina_lab)
Ian Pepper, environmental microbiologist. Director of the Water and Energy Sustainable Technology Center at the University of Arizona. Professor in the Community, Environment, and Policy Department in the University of Arizona College of Public Health. Leading efforts to detect COVID-19 in wastewater on campus, to prevent outbreaks. Director, National Science Foundation Water Quality Center. (@UAZPublicHealth)
On how rapid coronavirus tests work
Dr. Michael Mina: “COVID tests can actually be put onto a piece of paper, very much like a pregnancy test. In fact, it's almost exactly like a pregnancy test. But instead of looking for the hormones that tell if somebody is pregnant, it looks for the virus proteins that are part of SA's code to virus. And it would be very simple: You'd either swab the front of your nose or you'd take some saliva from under your tongue, for example, and put it onto one of these paper strips, essentially. And if you see a line, it means you're positive. And if you see no line, it means you are negative, at least for having a high viral load that could be transmissible to other people.
“It's a technology called lateral flow, which is because, essentially, the viral particles literally flow across the piece of paper and get pulled by these little proteins on the paper to create the line, essentially. And the technology has been around for a very long time for lots of pathogens. We use it all the time in clinics around the world, for things like malaria, for example. They can be produced very, very cheaply. And so far, we haven't put them to wide scale use for this virus during this pandemic. But they certainly can be available. And in fact, the company Abbott just the other day came out with a commercial version of it that was FDA approved at them. At this moment in time, it's approved only for use by medical professionals and with a doctor's order, for example, of symptomatic people. But it's a good first step in the right direction where we will start to see these, I believe, become more and more readily available to the general public.”
"They can be produced very, very cheaply. And so far, we haven't put them to wide scale use for this virus during this pandemic. But they certainly can be available."Dr. Michael Mina
On what ‘antigen testing’ is, and how that affects the way rapid testing works
Dr. Michael Mina: “An antigen is one of the proteins in the virus. And so unlike the PCR test, which is what most people who have received a test today have generally received a PCR test. And looking those types of tests look for the genome of the virus to RNA and you could think of RNA the same way that humans have DNA. This virus has RNA. Hut instead of looking for RNA like the PCR test, these antigen tests look for pieces of the protein. It would be like if I wanted a test to tell me, you know, that somebody was an individual, it would actually look for features like their eyes or their nose. And in this case, it is looking for different parts of the virus. In general, the spike protein or the nuclear capsid, these are two parts of the virus.
“The reason that these antigen tests are going to be a little bit less sensitive to detect the virus molecules is because there's no step that we call an amplification step. One of the things that makes the PCR test that looks for the virus RNA so powerful is that it can take just one molecule, which the sensor on the machine might not be able to detect readily, but then it amplifies that molecule millions and millions of times so that the sensor can see it. These antigen tests, because they're so simple and so easy to use and just happen on a piece of paper, they don't have that amplification step right now. And so they require a larger amount of virus in order to be able to detect it. And that's why I like to think of these types of tests having their primary advantage to detect people with enough virus that they might be transmitting or transmissible to other people.”
On how rapid testing could curb the spread of the virus significantly
Dr. Michael Mina: “When we're thinking about this virus and the control mechanisms that we have to deploy to be able to contain the virus at the community level, then controlling spread of the virus is priority number one. You want to stop people from spreading it to others. And the only way to really do that — we have masks and we have social distancing, and we've already shut down the economy. And these are extremely important pieces to really deal with the outbreak as it's emerging and to continue going forward. But we found that it's actually quite difficult to get everyone to wear masks and social distance. And we continue to see outbreaks, especially in the U.S., but elsewhere around the world. And so this is just one additional layer that can be a very, very powerful layer to actually stop people from spreading the virus to others by effectively giving them knowledge about their transmissibility status. And one thing that makes them so incredibly powerful is that they can be produced at such scale and for such few dollars each, such as such a cheap price tag, that you can actually start to think of a world where, like we just mentioned, people could actually be using these on a near-daily basis. And this gets very important, because it can actually mean that people can test themselves, before they go out each day and spread to other people.”
"It would serve to sever transmission chains by giving people knowledge of their potential transmissibility status.”Dr. Michael Mina
On how rapid testing would help normalize life during the pandemic
Dr. Michael Mina: “The way that this would work is that instead of a vaccine which uses your immune system to effectively stop you from transmitting to other people by preventing you from really getting a high viral load, these tests can fill in that gap by giving you knowledge about your status. And if we were to be able to say, give half of or everyone in a population, in a community, a 30 day supply of these tests, everyone or even just half of the people who choose to use them would wake up, they would use their COVID test and hopefully most people would be negative on any given day. But some people we know get this infection and don't gain symptoms from it, and especially don’t get symptoms right away, but can potentially spread to others before those symptoms occur. So these tests would actually give people an indication of their status even before they have any symptoms, where they could then make the educated decision to say, know, my tests just turned up positive, I'm not going to go to work today or I'm not going to go to visit my mom in the nursing home today, for example. And this is how we can stop spread from continuing. And literally it would serve to sever transmission chains by giving people knowledge of their potential transmissibility status.”
On the role of testing in a broader public health strategy
Dr. Michael Mina: “If you take a really big step back from it all, along with things like social distancing and mask wearing, these tests can actually do something a little bit more profound. And that is to drop what we call the effective reproductive rate of the virus. This is is a measure of how frequently and how quickly the virus spreads in a population, essentially. And if we can get that number to below one, it means that the virus starts to peter out of the population and the outbreak starts to die down. These tests, by severing transmission chains, if used, say, by 40 or 50 percent of the population on an everyday or every two or three day basis can actually stop whole outbreaks from occurring. So what I would really like to see is that these tests be taken up at a population level: Everyone still goes about all of their other mitigation strategies the same; they still wear masks; they still social distance; they still work from home, if that's possible. But the idea is to actually drop the overall prevalence of the virus at the whole community level so that everyone, including those who are making potentially poor decisions not to wear masks, become safer. And I want to see these tests kind of work for everyone to drop overall spread of the virus so that maybe we can see a return to normalcy.”
On the U.S. medical system’s lack of focus on public health diagnostics
Dr. Michael Mina: “In the U.S, we have a major focus on clinical medicine, and we have undervalued and underfunded the whole concept of public health for a very long time. We saw an example of this for, for example, when we tried to get the state laboratories across the country to be able to perform the PCR tests back in March, February and March, we very quickly realized that our public health infrastructure in this country just wasn't up to the task. We had very few labs that were really able to do enough testing to just meet the clinical demands. And so such a reduced focus on public health for so long has led to an ecosystem where our regulatory agencies, this being primarily the FDA, has a mandate to approve clinical medical diagnostic tests. But there's actually no regulatory pathway that is available or exists — and in many ways, we don't even have a language for it — for a test whose primary purpose is one of public health and not personal medical health
“That's really caused a problem. And a lot of times, it's interesting if you think about the United States, every single test that we get, with the exception maybe of a pregnancy test, has to go through a physician. And so that's a symptom of a country that has focused, and a society really, that has focused so heavily on the medical industrial complex. And I'm part of that as a physician. But I also am part of the public health complex as an epidemiologist. And I see that sometimes these are at odds with each other, medicine and public health. And this is an example where because all of our regulatory infrastructure is so focused on medical devices… If you're a public health person, you can actually have a huge amount of leeway in how your tests are working and still be able to get epidemics under control. And so there's a real tension here between the regulations that would be required for these types of tests versus a medical diagnostic test.”
"If you're a public health person, you can actually have a huge amount of leeway in how your tests are working and still be able to get epidemics under control. And so there's a real tension here between the regulations that would be required for these types of tests versus a medical diagnostic test.”Dr. Michael Mina
On the tests’ potential impact on “COVID fatigue”
Dr. Michael Mina: “People, rightly so, are sick of going to a drive through and having to go wait in line for a test and then waiting multiple days to get a result. It really limits what they can even do with that result. And so I think that in general, we're seeing COVID fatigue, and this is happening at all levels. But I think that these tests could reinvigorate, could sort of could add a new level of attention to people's willingness to defeat this virus. And that's because it's something that could be done at home that ideally, people don't have to go through a rigorous reporting process and getting calls. This is something the whole way that it works is you have enough people who just want to know their status. They want to know their kids’ status, especially as schools get open.”
From The Reading List
The Atlantic: "The Plan That Could Give Us Our Lives Back" — "Michael Mina is a professor of epidemiology at Harvard, where he studies the diagnostic testing of infectious diseases. He has watched, with disgust and disbelief, as the United States has struggled for months to obtain enough tests to fight the coronavirus. In January, he assured a newspaper reporter that he had 'absolute faith' in the ability of the Centers for Disease Control and Prevention to contain the virus. By early March, that conviction was in crisis. 'The incompetence has really exceeded what anyone would expect,' he told The New York Times. His astonishment has only intensified since."
The Wall Street Journal: "Abbott’s $5 Covid-19 Rapid Antigen Test Gets Emergency-Use Status From FDA" — "The U.S. Food and Drug Administration has granted emergency-use authorization to Abbott Laboratories ABT 7.30% for a $5 rapid-response COVID-19 antigen test that is roughly the size of a credit card. The low-cost, rapid-response test could be administered in a doctor’s or school nurse’s office and uses technology similar to home pregnancy tests. It returns results in about 15 minutes."
The Atlantic: "A New Era Of Coronavirus Testing Is About to Begin" — "In 24 hours, the testing landscape of the United States has transformed. Yesterday morning, all of the tests for COVID-19 — traditional or rapid — that had received emergency authorization from the Food and Drug Administration required an expensive machine and cost around $40 or more. In the afternoon, the pharmaceutical company Abbott announced that it had received FDA authorization to distribute a new type of test. This test requires only a coated-paper card and a small swab, and the scale of its production is stunning: Abbott says it will begin manufacturing 50 million of these tests a month in October. The tests will cost just $5 apiece."
Healthline: "Fast Isn’t Always Better: What to Know About Rise of Rapid Coronavirus Testing" — "Earlier this month, shortly before Ohio Gov. Mike DeWine was due to meet President Donald Trump at a Cleveland airport, the governor tested positive on a rapid antigen test for the new coronavirus, SARS-CoV-2, that causes the disease COVID-19. Two follow-up tests, using a more accurate polymerase chain reaction, or PCR test, showed the governor didn’t have the virus. This kind of false positive with an antigen test isn’t an isolated incident."
Vox: "Rapid $1 Covid-19 tests exist. Why can’t we get them?" — "To get the US pandemic under control, a growing number of health and medical experts are making a clarion call for an additional testing approach to COVID-19. What we need, they argue, are at-home rapid tests that look for antigens, proteins the live virus makes. These kits would allow anyone to test themselves for the coronavirus any time (and anywhere) for between $1 and $5, and get results in about 15 minutes. No doctors, labs, expensive machines, or special chemicals required."
This article was originally published on August 31, 2020.
This program aired on August 31, 2020.
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