Are known cases just the tip of the iceberg? A new test holds promise – and peril – for how we fight back against the disease.
Story Transcript
This is a rush transcript and may contain errors. It will be updated.
Kim Brown: We’re facing a multipronged problem here in America trying to get a handle on COVID-19. The global pandemic that is affected so many with at least 170,000 dead here in the United States and at least five million infected.
For the purposes of today’s conversation, we’re going to focus on two key areas, the dearth of widespread testing and the potential perils of rushing through a vaccination process. Specifically skipping over phase three clinical trials in order to have a vaccine widely accessible for hundreds of millions of people.
Our guest today says that we would have a much better handle on COVID if we scaled up screening for the virus instead of relying on slower, more costly diagnostic lab tests. Our guest also says that skipping phase three trials is not likely a good idea. Especially when we’re talking about dispensing potentially hundreds of millions of doses of this vaccine in just a few short months.
Zoe McLaren is a PhD and associate professor at the University of Maryland Baltimore County’s School of Policy. She has an extensive background in combating infectious diseases like tuberculosis, HIV, and COVID-19 from a health and policy perspective.
You recently wrote a piece on the conversation.com titled, Rapid Screening Tests That Prioritize Speed Over Accuracy Could Be Key to Ending the Coronavirus Pandemic and she joins us today. Professor thank you so much for making some time to speak with us.
Zoe McLaren: It’s a pleasure to be here.
Kim Brown: Professor, from your pen to researchers ears, August 15th, Yale University researchers announced a new rapid test for COVID-19 called saliva direct, which has been granted FDA emergency approval and speaks directly to the crux of your piece. If you could for us professor explain to us the difference between diagnostic testing for COVID-19 and screening tests for the virus and why the approval of methods like saliva direct could be significant?
Zoe McLaren: Sure. The two types of testing, diagnostic testing and screening testing have a few different important differences. One is that diagnostic testing is generally in medical settings and then we wait for somebody to decide that they’re sick, have some concern about exposure, and come to get tested.
The idea with screening testing, is it supposed to be much more widespread and we’re going to screen a big proportion of the population, including people who have no symptoms or no known exposure, but still could be infected.
When we think about diagnostic testing and screening testing, the type of tests we actually do for those two purposes is also different. In the diagnostic setting, we have someone who maybe has serious health issues going on, have symptoms that are similar to COVID, or they have symptoms that aren’t very similar to COVID, but they want to rule it out. So we need a test that’s going to have very high accuracy because we need to know for sure because somebody’s life is on the line. There’s all of the medical profession available to help them, but only if they know exactly whether it’s COVID or what else it might be.
In terms of screening testing, the idea is we want to screen as many people as possible as frequently as makes sense. So we maybe want to use a test that’s a little bit less accurate that we could still catch an awful lot of cases, but we may need to trade off some of that accuracy in order to be able to scale up quickly, to be able to test that many people, and also to be able to do rapid tests.
The idea is they’re not kind of much less accurate, but we’re going to prioritize that a little bit less because the point of screening testing is broad access to testing. That screening testing is one of the main ways that we can get to people who have no symptoms.
One of the biggest challenges with the coronavirus, that we’re facing right now, is that people can be contagious and spreading COVID, but they have no symptoms and they have no indication that they are infectious or contagious.
Screening testing is basically a way to bring access to testing to as many people as possible to catch those people so that they can find out that they’re contagious and take the appropriate precautions to make sure they don’t spread.
Kim Brown: Hearing someone in public health say that it’s okay for a test to be less accurate is a bit counterintuitive. Why is speed over accuracy okay when it comes to COVID-19 testing?
Zoe McLaren: Remember the idea is there’s diagnostic and there’s screening. With screening, the idea is we’re actually not specifically supposed to be diagnosing, we’re basically trying to catch cases. We may have some issues of false positives, but the idea is that the group of people who have a positive screening test are going to be much more likely to be contagious.
Among that group, they may want to get further diagnostic testing to be sure or they could just take some precautions and make sure that they quarantine themselves for a few days to make sure that they don’t spread the virus.
Kim Brown: It’s been estimated that the true number of people infected with COVID-19 in the U.S. is exponentially higher than what has been reported. Would the screening tests actually helped to reveal the true number of cases that we have currently percolating?
Zoe McLaren: Exactly, so that’s part of what it does. One of the reasons why we have kind of the official numbers of cases that have been confirmed, but then we also know there are a lot more cases out there is that access to diagnostic testing is limited.
In early July there were very long waits to get tested. You saw long lines of cars in Houston and other parts of the South, trying to get access to a test. A lot of people didn’t have that much time to wait. So they just stayed home, didn’t get tested, maybe they developed symptoms and then went to get tested at the emergency room. The idea is that with screening testing, we’ll be able to catch more of these cases and so we’ll have a better sense of how many cases are out there.
I always think about that kind of counting the number of cases is really just a pathway towards reducing the number of cases. Testing is not just a measurement tool. Testing is actually the main engine for reducing the pandemic because people don’t know that they’re contagious unless they’ve been tested.
If we get access to screening tests to a wide proportion of the population, then more people will know that they’re positive. So we have that additional data, but that data helps us because that individual knows their positive, they know that they can take precautions to avoid spreading it, and then we can also try to look for more cases to make sure we’re catching all of them.
Kim Brown: Professor, we have seen this pandemic become wildly politicized from the wearing or not wearing of masks when out in public. To the way that people are even prioritized in getting tested. In many places, you can’t even receive a COVID-19 test unless you are already demonstrating symptoms.
This has been not the best way to handle this, at least from the outside looking in, I’m curious as to what your take on it is as someone who has worked in the public health sector, who has dealt with infectious diseases, and dealt with how states and agencies locally and nationally can control and help affect the spread of this. Over the past five months, what has been your reaction to the way that this has been handled not only federally, but at the state level?
Zoe McLaren: I think, I mean at the state level, there have been kind of a wide range of responses. Here in Maryland, Governor Hogan has been really at the forefront, really been a pretty strong leader on COVID-19 policy. I think that’s the thing about widespread testing is that it’s something that everybody wants, that it shouldn’t be politicized.
Everybody wants to know whether they’re contagious or not because if they know that they’re contagious, they can protect their friends and their family and avoid spreading the disease.
The idea is that widespread testing is not a political thing. That it benefits every individual and in some ways has a greater benefit than masks because masks the benefit is unclear. Masks help slow the spread, but you don’t always see the benefit so you don’t always see the infections that you’re potentially avoiding by wearing a mask.
With widespread testing you see the benefit right away. You can walk in wondering if you are contagious for COVID or not, and walk out knowing whether you are or not, and then make a really good informed decisions based on that information.
Kim Brown: Professor, you had a Twitter thread go viral recently where you detailed and outlined the dangers of skipping phase three clinical trials in the hopes of developing a vaccine for COVID-19.
In recent days, the Russian government has announced that they have a vaccine ready to go this fall, but allegedly they are moving forward before starting or even completing a phase three trial.
Why is this a bad concept not only for what the Russians claim to have achieved and for companies here in the U.S., pharma companies, not just in the U.S., but generally in the West that are working on a vaccination and who might contemplate cutting corners during this process? What are some of the drawbacks to that phase two versus phase three outcomes can sometimes be different?
Zoe McLaren: Sure. I think it’s important to note that my Twitter thread was in response to a couple of people who’d posted in my view quite misguided ideas that we should skip phase three, but it’s very important to note that the FDA and the U.S. government have no intention whatsoever of skipping phase three. They know it’s a terrible idea and they’ve committed very strongly to following through with the full regular phase three process, which I think is very wise.
I can’t comment too much on Russia. It’s hard to know kind of what exactly is going on based on the information that’s coming out of that country, but the idea here is that having a vaccine, for example, in vials sitting on shelves is not what protects us. What protects us is the actual vaccinations and people are going to actually get the shot and that provides the protection.
If Russia says they have a vaccine, well, that’s sitting on the shelf right now until they have a large proportion of their population willing to get the injection, it’s not going to provide any protection to them.
Why is it so important to follow through with the full phase three trials? The idea is phase one and phase two provide preliminary information. They provide preliminary data, a small sample of a few hundred people basically testing the new potential vaccine to make sure that it meets preliminary safety and effectiveness thresholds.
Phase three is when it’s broadened and in this case, phase three looks like it’s going to include 30,000 people, so much larger sample of people. That’s when we’re really going to get the real safety and effectiveness data.
If the vaccine has adverse effects, this is when we might find out about that. Oftentimes the adverse effects might be very rare. So we need a large number of people to have the vaccine, to be able to have good enough data to know that it’s the vaccine that’s producing these adverse effects.
We also need to get a good estimate about the effectiveness. We could potentially have a vaccine that’s totally safe, but is not at all effective. That’s actually can be very dangerous because if people think they have protection from a vaccine, they’re going to go and make decisions that could actually put them at great risk if that vaccine offers no protection. The idea that as long as it’s safe who cares about the effectiveness, doesn’t actually make a lot of sense and can actually lead to some very bad outcomes.
It’s also true that even if the vaccine is safe and effective, we still want to complete all of the phase three trials. That is because we want to make sure that everybody believes that the vaccine is safe and effective.
To do that, well we need to get the medical establishment and the experts on board so that the experts are saying, “Yes, we believe this is safe. I would get the vaccine. I would recommend my friends to get the vaccine and my family to get the vaccine.”
To do that, to kind of get experts like me on board, we really need to complete the phase three trials because I won’t be satisfied that it’s safe and effective until I’ve seen that the full data and chatted with my colleagues, listened to Dr. Fauci for example, if he says it looks good, that’s a pretty good benchmark that it’s safe and effective because that’s part of how we start off by telling everybody that the vaccine is safe and effective. That’s going to get people who want to actually get in line and get the vaccine.
High take-up of the vaccine is really important to because it’s likely that the very first vaccine we get is not going to offer 100% protection. It can offer as low as 50% protection. I think that’s the lowest bar that the FDA is allowing kind of for its approval process.
We may have a vaccine that offers some protection, but not complete protection. With a vaccine like that, we actually get protection not from just getting it ourselves, but from when other people in our community get the vaccine. If we have a 60 or 70% effective vaccination, the higher the proportion of people who take it, the closer we get to vaccine induced herd immunity. Where we get the protection because we’re all protected partially, but between all of that partial protection it kind of adds up to quite a lot of protection.
That’s the important thing with the vaccine is that it’s not just, I want the vaccine now, so I can get it protected. It’s that we want a vaccine that we all know is safe and effective and it’s going to be able to reach high levels of 70, 80, 90% take-up among the population because that high take-up is what’s going to end the pandemic, not the partial take-up of a partially effective vaccine.
Kim Brown: I wanted to circle back to what you mentioned about the efficacy rates. That the FDA hopes that a potential vaccine would at least be 50% effective, but we do know that for the seasonal flu, for example, some vaccines or the flu vaccination specifically, given the season, given the strain, can only effectively immunize about 30% of those who take the vaccination.
Given that humans currently have zero immunity to COVID-19, is any level of efficacy better than what we have now? Will we accept a 30% effective vaccination as opposed to having no vaccination at all?
Zoe McLaren: I think that that’s a question for down the line. Right now the vaccine process looks very promising and it looks like we should have a vaccine that meets that 50% threshold. We have multiple vaccines that are in the pipeline.
If the first one doesn’t meet that threshold, there’ll be another one right behind it that will likely meet that threshold. I think the idea is if we have a vaccine that’s less effective than that, then it’s really difficult for people to make appropriate decisions about what’s safe and what isn’t safe when you just have 10% or 20% effectiveness of the vaccine.
The idea is I really don’t want to talk about a vaccine that’s less effective than that. That’s basically not going to be effective, and it’s going to probably muddy the waters and make it really difficult for people to make decisions. We want a vaccine that’s going to offer us some protection, that’s going to help us get back to normal.
With the flu vaccine, so some of the flu vaccines are not 100% effective, but if you’ve noticed that during flu season, how many reminders you get to get a flu vaccine. That’s the idea that with a less effective vaccine, if we can get take-up rates to be high enough, then that boosts the effectiveness for everybody.
Even for the flu vaccine, which is a much less deadly disease than COVID-19, we still do a big push to make sure take-up as high. So that’s why it’s even more important with COVID-19 that we have really, really high take-up because that is with a less than 100% effective vaccine that’s okay because we can get take-up high enough to kind of end the pandemic and help us get back to normal.
Kim Brown: We know that COVID-19 is particularly deadly to those who have underlying conditions ranging from diabetes, to heart conditions, or breathing conditions and I’ve seen a number of healthcare professionals or people who work in this sector who are working on a vaccine make a specific call out to communities of color, to African Americans, to Latinx people, to participate in these vaccination trials.
I would imagine because the virus is impacting those communities disproportionately in a more deadly way, but do vaccines sometimes work different in other races? Why is it so important to make sure that communities of color participate in these vaccination trials despite historical reasons why they may not want to? Thinking of the Tuskegee Experiment and the story of what happened to Henrietta Lacks in Baltimore? Talk to us about that angle of it. How in a way COVID-19 is a bit of a racialized issue here in the U.S.
Zoe McLaren: Yeah and that’s a really question. We don’t know with this new vaccine whether it will have different side effects or different effectiveness in people of color. That’s part of the process of phase three. That’s one of the important questions that the phase three process is going to answer because if we don’t include people of color in phase three we’ll, then we get safety and effectiveness data that doesn’t apply to communities of color and it could put them at risk.
Involving people of color in the phase three trials is really, really important. I encourage anyone and everyone if they’re willing to participate in that trial and help produce this really important information about the vaccine.
That’s kind of one thing that we don’t know for sure. That’s one of the reasons and completing the phase three trial, historically looking at the Tuskegee Experiment, for example, that was a situation where it was kind of a process where it undermined trust in the medical establishment and medical research that persist to this day.
The Tuskegee and with Henrietta Lacks as well, these violations of trust are not something that just happens in the past. Those violations of trust it takes a lot to kind of rebuild trust after a situation like that. That’s still causing kind of challenges in communities of color who don’t fully trust the medical establishment and to be quite honest, I don’t blame them. The medical establishment is not always designed with those communities fully in mind.
I encourage people to be a part of those vaccine trials so we get good information and that those trials can basically conclude and let communities of color know that the vaccine is safe for them and effective for them as well.
Kim Brown: Lastly professor having worked with different infectious diseases, specifically a disease like tuberculosis, where students attending public school are required to have a tuberculosis vaccination before they are legally allowed to attend.
We see this myriad of other vaccinations for different diseases like meningitis B and the vaccine against human papillomavirus, HPV, being pushed a lot on school aged populations. However, there are colleges, there are some public school systems that do intend to reopen for in-person classes.
As someone who has worked with, again, a disease like TB, that your child has to be vaccinated against in order to attend school, but to see COVID-19 be allowed for students to attend school, either colleges or just grade school while this potentially deadly virus is still very much out in the population. What is your reaction to that?
Does that scare you at all? And as someone who works in higher ed, what is your take about returning for in-person learning during the semester before a vaccination is wildly available?
Zoe McLaren: Given to infants, but what’s usually required for public school is a test to make sure people haven’t been exposed to TB. To make sure that they are having that tuberculosis skin test. It’s a test for exposure that you have TB, but not necessarily a vaccine.
Yes, I’m very concerned about kids going back to school with COVID-19, but I’m also concerned about kids not being in school for a long time because we know that that’s really difficult for them. I think it’s a really difficult question in terms of the trade offs.
I think that’s one of the big reasons why I’ve been focused on testing since March and continue to be focused on that because the testing component and screening testing is a way to catch cases and to help kids and college students to go back to school in a way that’s safe for students, and for staff, and for families, and for the surrounding community. I think that we need to think very carefully about the return to school and incorporating screening testing is a great way to help kids go back to school sooner and allow them to do it safely.
Kim Brown: We’ve been speaking with Zoe McLaren. She is a PhD, also an associate professor at the University of Maryland at Baltimore County.
Her latest piece appears in the conversation.com and it is titled, Rapid Screening Tests That Prioritize Speed Over Accuracy Could Be Key to Ending the Coronavirus Pandemic. We’ve already seen at least some movement on that very shortly after your piece was published Zoe. So very serendipitous there for that new news to come out on the heels of your piece being published.
Thank you very much for making some time to speak with us, we appreciate it.
Zoe McLaren: I will say there is an awful lot of testing technology that’s in the pipeline. That’s not just that one piece of news there will be more news, it’s going to come quick. There’s going to be a lot of it. The technology we basically have it already. We just need to put into practice. Thanks so much for having me.
Kim Brown: Thank you and thank you all for watching The Real News Network.
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