[music]

Brian Lehrer: Brian Lehrer on WNYC and now our latest edition of Ask a Virologist, my questions in yours for a virologist Dr. Angela Rasmussen, who is an affiliate at the Georgetown Center for Global Health Science and Security, a research scientist at the Vaccine and Infectious Disease Organization, VIDO, which is based at the University of Saskatchewan. She's also a contributor to Slate where her latest is simply called, Why did the CDC change its mass guidance now? Our Ask a Virologist call-in number is 646-435-7280, 646-435-7280 or tweet a question @BrianLehrer. Hi again, Dr. Rasmussen, welcome back to WNYC.

Dr. Angela Rasmussen: Thanks so much for having me back, Brian.

Brian Lehrer: As listener calls are coming in. My first question is about boosters. Here's Dr. Fauci speaking at a live event yesterday with the news organization, Axios.

Dr. Fauci: I think we will almost certainly require a booster sometime within a year or so after getting the primary because the durability of protection against Coronavirus is generally not lifelong.

Brian Lehrer: Do you agree with Dr. Fauci on the science of boosters?

Dr. Angela Rasmussen: I do agree with Dr. Fauci and I'm really glad that actually, Dr. Fauci addressed this because I think a lot of our conversation about boosters has revolved around the variance and the idea that eventually variants are going to emerge that are completely capable of escaping a vaccine-induced immunity. We might need boosters for that reason, similar to the reason that we need boosters every year for influenza. SARS-CoV-2 and influenza are quite different, and with influenza, there are many, many different strains that are already circulating. So far with SARS-CoV-2, the variants are actually not that different, and so far the vaccines appear to be able to protect against all of them.

I think the real conversation to have about boosters is exactly what Dr. Fauci was talking about. Not so much the idea that the virus is going to evolve around the vaccines, but that the vaccines are not going to produce durable immunity that lasts for the duration of somebody's lifetime. We have many other vaccines for which boosters are needed for that exact same reason. I'm glad that we are talking about boosters in that context because I think that that is actually right now, anyway is the most likely scenario.

Brian Lehrer: Of course, we get flu shots annually, we get our tetanus boosters periodically, all those things. If this is true, how do we time it so that vulnerable people like older people and immunocompromised people get boosters before they get sick?

Dr. Angela Rasmussen: This is a really tricky question because ultimately the only way to assess durability is to actually look at vaccinated people over that same period of time and start to look at when their immunity wanes. Right now, the only way to do that is to see an uptick in cases among vaccinated people. Obviously, that's not desirable because we want to make sure that as many people as possible are protected and not getting sick. We are closer to identifying what are called correlates of protection.

Correlates of protection are basically laboratory measures, looking at antibodies, for example, or other markers that you can look at in a lab without needing to do a clinical trial and actually have people get sick to determine if the vaccine is still providing protection. If we can develop good correlates of protection, then we can monitor people who are vaccinated, see when they're their correlates of protection drop below a threshold that is thought to be protective, and then authorized boosters on that basis.

Brian Lehrer: Speaking of the flu shot, I was thinking the other day that they give bigger doses of the annual flu shot to people over 65. Can you explain why that is briefly and if bigger doses of the COVID vaccine might be called for, for seniors and immunocompromised people too?

Dr. Angela Rasmussen: Yes, absolutely. We do know that for many vaccines in older people, sometimes you do need a larger dose of that vaccine in order to get the same type of immune response. That's just because as we age our immune system, unfortunately, ages too, and it's not as responsive as a younger person's immune system to a given stimulus, in this case, the vaccine. I think it's completely possible that, for older people, we may determine that we need to be giving larger or more frequent doses potentially or more frequent booster shots of these vaccines to ensure that they have the same level of protection, particularly because they are at a much higher risk of developing severe COVID-19.

I think that that this is something that we've already started to see a little bit in the case of some outbreaks that have happened in long-term care facilities. For example, among older people who have been vaccinated, there does seem to be, at least in these clusters, a higher rate of breakthrough infections, including symptomatic disease. It may well be that we either need to provide an adjuvant, which is an additive that makes the immune system respond more robustly, or give larger doses of these vaccines, or potentially both.

Brian Lehrer: Right, because that wasn't done in the first round where I think everybody got the same thing.

Dr. Angela Rasmussen: Exactly.

Brian Lehrer: You also wrote about, on your Slate article, the greatest susceptibility of immunocompromised people to breakthrough cases. I think we don't talk about them enough. First of all, how do you define an immunocompromised people? Who are they? What is it more precisely that they have? How do they know if they should get the vaccine or how effective their vaccines are for them as individuals?

Dr. Angela Rasmussen: This is a really tricky question, and I'm glad that you asked it in this way, Brian, because immunocompromised people, that can mean a lot of different things. That can mean everything from somebody who is taking a steroid to treat something like asthma, to somebody who is very, very immunocompromised, such as somebody who has an organ transplant and is taking very powerful immunosuppressive drugs to allow them to maintain that organ transplant and prevent them from rejecting their transplanted organ.

We've seen so far that, in people who have had organ transplants, and again, are taking these really, really powerful immunosuppressants, that they don't have much of a response to the vaccines, which is not surprising because of the types of immunosuppressants that are taken by organ transplant recipients are targeting essentially the same part of the immune system that responds to vaccines because that's also the part of the immune system that mediates organ rejection. We definitely need to be thinking about those people.

It's a lot less clear what that looks like in people who are taking other types of immunosuppressants, such as people who have an auto-immune disease, people who have an inflammatory disease, like asthma or rheumatoid arthritis or psoriasis, things like that. We really do have a lot more work to do in this area because all immunocompromised people are not the same. One thing that we do know is that, at least in people who are severely immunocompromised, the vaccines don't appear to be that effective.

To me, the take-home message from that is not so much that, that we need to figure out ways to make those vaccines more effective in those groups of people. We should continue to try that. We also need to think about getting out the message that everybody else who is not immunocompromised should be taking the vaccines to provide population-level protection for those who just aren't going to respond to them.

Brian Lehrer: Ask a Virologist with Dr. Angela Rasmussen. Pam in Manhattan, you're WNYC. Hi Pam.

Pam: Hi. Thank you. How does the virus know to mutate?

Dr. Angela Rasmussen: That's a great question, Pam. The virus doesn't actually know to mutate. Viruses are essentially little machines, they don't know how to do anything. They're programmed essentially to replicate, and that is what evolution dictates a virus needs to do because if it doesn't replicate, it won't exist anymore. Viruses mutate when they replicate just by the way the system works essentially. The enzyme that copies the genetic material of the virus, essentially the instructions for the virus to carry out all the steps of replication, makes mistakes sometimes, and it can't correct those mistakes, the same way that we can when we copy our own genetic material.

As the virus replicates, mutations are acquired just through random chance, and sometimes it's like winning a lottery for the virus. Sometimes that mutation will occur in a place that gives that virus some advantage. We've talked a lot about the variance in the press and as a society, the variants that people are concerned about are variants that have mutations in the spike protein, that's the part of the viral genome or the genetic material that encodes the protein that allows the virus to enter and infect cells. That's also, what's targeted by all of the vaccines. If a virus gets a mutation in that spike protein, in an important part of the protein, it may have different properties such as being more transmissible. It may be able to partially evade some of the vaccine-induced immune responses. That's why the virus is mutating. It really isn't something that the virus knows how to do, it's something that's baked into the way the virus works. Sometimes, unfortunately for us, that gives the virus some kind of advantage. The way to get around this is to take away opportunities for the virus to replicate, then it won't be able to mutate because if it can't copy its genome, it's not going to make mistakes. It's not going to acquire mutations and we won't see new variants.

Brian Lehrer: June in the Bronx. You on WNYC with Dr. Rasmussen. Hi, June.

June: Hello.

Brian Lehrer: Is this June in the Bronx?

June: Yes. Hi, good morning, Brian. Good morning [unintelligible 00:10:34] good morning to your guests.

Brian Lehrer: Good morning.

June: Yes. I'm one of the individuals that have the immunocompromised situation. I have asthma traits and I went to a doctor and what my body is doing is that the same cells in my system neck is growing. That could be maybe like that cancer form maybe. My level [unintelligible 00:11:03] keeps going up and down so now they're saying they're going to have to watch it and see what is really going on because my white blood cells is the issue. Then the cells, my numbers keep going up and up for some reason.

Brian Lehrer: Then your question, as you told our screener was whether, with the condition you just described, you can safely live with someone else who is fully [unintelligible 00:11:26]?

June: Yes. I'm totally vaccine and the other person totally vaccine. Would that be okay? I'm compromised in an apartment.

Brian Lehrer: Dr. Rasmussen. You got the question, right?

Dr. Angela Rasmussen: Yes, I do. In terms of living in a household with somebody who's fully vaccinated, if you are immunosuppressed, that is safe. You do need to be more careful, however, when you're going out into the public. If I were you, I would continue to talk to my primary care provider because that is going to be the person who's going to tell you what the best situation is for your specific medical condition. People who are fully vaccinated are much less likely to get infected, to begin with. Then if they are infected, we don't have as much evidence about this, but we are starting to see some that they're much less likely to also transmit the virus to others.

You should be safe to live in an apartment with somebody who's fully vaccinated and both of you are fully vaccinated. You said that you are fully vaccinated, June. That doesn't necessarily mean that just because you're immunosuppressed and seen fluctuation of your white blood cell counts, that you have no protection from the vaccine. That's also something you're going to want to talk to your medical provider about, but there are ways to determine, for example, if you've mounted an antibody response to the vaccine.

That would mean that you do also have some degree of protection. I would say that it's safe to live in your current living situation, but just be extra cautious when you're going out into public, specifically, when you're going into public indoor spaces, where there are people from outside of your household and you don't know their vaccination status.

Brian Lehrer: We're almost out of time, but based on everything that you've been talking about, you're a virologist not a labor or workplace policy person, but do you have an opinion about accommodations for immunocompromised people or just older people, based on what you've been saying, that workplaces should institute going forward? Like of the serious and fatal breakthrough cases, although they're very, very rare, 80%, according to the CDC have come in people over 65. Should older or immunocompromised people get more work from home accommodations or anything like that? If you've thought about that question based on the science.

Dr. Angela Rasmussen: I have thought about that question. I think about that question a lot because that really is going to be crucial for us all to move on as a society if we are not going to mandate vaccination, which I also think might be a bad idea. One good way to get people on the fence to say, " No, thank you," is to tell them they have to do something. If we are not able to win enough hearts and minds over to the cause of vaccination, we are going to have to be thinking about how we can protect people from outbreaks that might happen in communities where there are a lot of unvaccinated people, including older people, including immunocompromised people, including people who may not have the same level of protection from the vaccines.

I think that this is really going to be a multi-pronged strategy. We can't rely solely on vaccines, even though they're wonderful, and they are really the long-term sustainable way out of this for all of us around the world. We also have to think about making accommodations in public spaces that will make those spaces safer. We shouldn't be discouraging mask use. I know that in Texas, for example, they've passed a law now that the governor signed that prohibits mask mandates. We shouldn't be doing stuff like that. We should allow people to continue wearing masks if they feel that they're at risk.

We should be encouraging and enabling workplaces and schools to improve air quality, to improve ventilation, and air filtration systems. That's going to bear fruit for us down the road too because certainly having clean air, having a healthy workspace is going to be good for other things that are besides COVID as well. This is really something that needs to be thought about a lot. It's not just vaccines that are going to get us out of this, we need to make sure that we are making safer indoor public spaces for everybody.

Brian Lehrer: Thank you so much for that. That's our latest addition folks of Ask a virologist, my questions in yours for a virologist Dr. Angela Rasmussen who is a research scientist with the Vaccine and Infectious Disease Organization, VIDO at the University of Saskatchewan, and an affiliate at the Georgetown Center for Global Health Science and Security, as well as a contributor to Slate where her latest that includes writing about the things we talked about in this segment is simply called Why did the CDC change its mass guidance now? Dr. Rasmussen, thanks so much.

Dr. Angela Rasmussen: It's really my pleasure, Brian. Thanks for having me back.

Copyright © 2021 New York Public Radio. All rights reserved. Visit our website terms of use at www.wnyc.org for further information.

New York Public Radio transcripts are created on a rush deadline, often by contractors. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of New York Public Radio’s programming is the audio record.