By Rose Hoban

Lisa Gralinski is a virologist who studies human coronaviruses. She’s an assistant professor in the Department of Epidemiology at the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill. She’s been studying human coronaviruses for close to 13 years and as such, has been a much sought after expert during the SARS CoV2 pandemic.

Gralinski sat down to talk to NC Health News about what’s happening with Delta, what we can expect next during the pandemic and how to protect unvaccinated kids. (This conversation has been edited for length and clarity).

NC Health News: There’s a lot of talk about breakthrough infections and I think that’s the thing that is really kind of preoccupying people. So, let’s start with the basics: What’s the risk of getting COVID if you’re vaccinated?

Lisa Gralinski: It’s definitely further from zero than we’d like it to be. 

I think when the initial Pfizer and Moderna trials read out last fall, they were so much more incredible than we ever could have imagined or hoped going in. The goal with these vaccines as they were being developed through Operation Warp Speed in 2020 was to get something that was more than 50 percent efficacious against symptomatic disease and we ended up in the spot where it was 90, 95 percent effective. And we also had this really incredible reduction in any infection at all. I think that helped all of us move the goalposts quite a bit.

These are basically almost like magic shots that are going to keep all of us incredibly safe. And even though it seems a little bit too good to be true, I would say that I bought into some of that as well, thinking, “Alright, this is potentially going to wind down so much more quickly than we thought, you know, the real challenges are going to be the logistics of cold chain, and how do we get these vaccines everywhere that they need to go, etc.” 

But now we’ve kind of come back down to earth a little bit, realizing that these vaccines are still incredibly protective and do a great job of preventing severe disease and preventing hospitalization and preventing death. And they’re still, in the 80s percent effective, but they’re not this magic bullet that stops the virus from ever getting to you at all. 

You know, over the past few weeks, I’ve been struggling to wrap my head around the fact that, you know, probably at some point, I feel like we’re all going to be exposed and be maybe a little bit more vulnerable than I was thinking, and it’s upsetting. 

NCHN: I’ve been hearing that, too, that the reality is that we’re all going to get it sometime. So you could be unvaccinated and get COVID and have it be bad. Or you could be vaccinated and get it, and you get sick, but likely not as badly. But at some point in time over the next three, four years, we’re going to be exposed to it and probably going to get a disease of varying severity.

Gralinski: Unfortunately, I think that is right. And I would definitely like to have as much immunity built up in my body from vaccination as possible, when I am inevitably exposed to it. 

It is possible that I have already been exposed and didn’t know it, because either my immunity was good enough that I didn’t get infected, or there was something asymptomatic happening. It’s not like I’m being tested on a weekly basis or anything. So it’s possible, something happened that I and the people around me were blissfully unaware of.

NCHN: And now, of course, if you got tested, you would have antibodies anyway, because you were vaccinated?

Gralinski: Yes. If you’ve been vaccinated, you will only have antibodies to the S or the spike protein and you would only have antibodies to the N or nucleocapsid protein if you’ve had a natural infection. I’ve had some friends question me after they’ve given blood and be like, “Hey, there’s something weird with my result there.” The Red Cross tests blood donations and they look for both the N and the S. Some people are showing up with both when they didn’t realize it.

NCHN: Oh, interesting! So you can see then if you have been infected.

Gralinski: That’s assuming you generated an antibody response because we know that some people were infected and don’t have antibodies.

NCHN: It almost feels like, in retrospect, the best strategy would have been to get your shot. Then in, say April or May, before Delta really came around, you should have gone out and partied with a lot of people, gotten exposed and had an asymptomatic case. Then you’d have both kinds of exposures!

Gralinski: You know, studies of healthcare workers where people had those early infections last year before we had vaccines available, and then even just one dose of an mRNA vaccine. Those people have the best antibody responses of anyone.

I don’t think any studies like that have been done with the Johnson & Johnson platform.

NCHN: That’s really fascinating. So what’s the chance of someone who’s vaccinated spreading COVID?

Gralinski: It’s definitely lower, vaccination doesn’t make you bulletproof, but it lowers your chance of getting infected overall. It definitely substantially reduces your chance of having severe symptoms needing hospitalization, ICU [admission], mortality, the vaccines do an incredible job with that. They reduce your risk of transmitting and some of that’s because they reduce your risk of getting infected at all. Even with Delta, we still see less transmission. 

And we’re starting to see papers come out saying that of people who were vaccinated who do develop COVID, there’s also less chance of developing long COVID so vaccination still seems like a win-win-win-win-win to me.

NCHN: So, I go to see my 93-year-old mother every four to six weeks, she’s vaccinated, I’m vaccinated. I test ahead of time to be sure, I get on the plane, I wear a mask there, but then I stay with her for a couple days and I’m unmasked. Is that kind of activity safe?

Gralinski: I think it’s mostly safe. It’s not completely safe. I don’t think anything is completely safe at this point unless we’re all going to just live in completely isolated bubbles, which isn’t practical for mental health reasons, financial reasons. 

To give a super personal example, last year, my dad passed away, not from COVID, and we weren’t able to have the funeral. We finally had it this August up in Massachusetts, and when we planned it, things seemed like they were much more under control. And then in the weeks leading up to early August, we were like, “My dad’s funeral can’t turn into a COVID superspreading event!” 

Luckily, it’s Massachusetts. Vaccination rates are quite good there, better than North Carolina and everyone wore masks indoors during the funeral, then we had an outdoor seating food area. I felt pretty good about this. Overall, I felt good about the contacts that I had where I was either masked, or outdoors with people who I didn’t know as well, or indoors with a select group of people who I do know their vaccination status. But I still took a couple days to work from home when I got back to North Carolina and I got tested just in case.

A friend of virologist Lisa Gralinski made this cake for her in Sept. 2020 that she posted to her Twitter feed. Her tweet: “Best cake ever? It’s been a brutal year all around so I asked my friend Khara to make us a ‘virus fighting unicorn cake’. This is the amazing design came up with and it has definitely brought a lot of smiles to lab today!” Image courtesy: Lisa Gralinski/ Twitter

NCHN: My family has a similar situation, my cousin has planned an aunt’s memorial for October. My mom really wants to go, and by then, maybe she will have had a booster dose.

Speaking of booster doses, should I get a booster? Will it protect me? Who should get a booster?

Gralinski:  I have a lot of mixed thoughts about boosters, third doses. If you’re immunocompromised, a third dose, I think, is 100 percent the right way to go. That should just be part of the stated COVID vaccine regimen. There’s been a lot of good data showing that for people who are moderately to severely immunocompromised that a lot of people don’t generate a good response from just the two doses and a third one makes a substantial difference.

NCHN: Who qualifies as immunocompromised? 

Gralinski: Solid organ transplants, for one. If someone has had a kidney transplant and their antibody levels were super low after just two doses, a substantial portion of those patients had a much better antibody response after a third dose. Different people, like cancer patients, or people who are on immunosuppressive drugs for different autoimmune diseases, things like that, the CDC definitely has a list that they’re going by.

NCHN: There are corners of the internet that are arguing that having people vaccinated is promoting mutations. Is that true? What do the data show?

Gralinski: We’re not seeing data to indicate that yet. 

If you want to follow the thought exercise, there’s a lot of data in the norovirus field or in the flu field, for example, to indicate that waves of viruses will go through the population. And once everyone who’s going to be exposed to this current version has been exposed, the virus will evolve itself a little bit to be able to evade that immune response and then come through in waves again. But we haven’t seen anything like that with SARS 2 and COVID. 

Some of that is probably because coronaviruses mutate less readily than other RNA viruses, they do have some proofreading function. With other human coronaviruses like with common cold-causing viruses, people don’t develop super long lasting immunity. Coronaviruses are really good at masking themselves from the host immune response, so you get a little bit of immune response, but it doesn’t last for a lifetime. 

This isn’t like you get your measles vaccine, and you’re set for a long, long time with natural coronavirus infection. That’s part of why we think it’s so important for people to get vaccinated because you’re showing the body’s immune system the key protein on coronavirus – the spike protein – without any of the extra proteins that coronaviruses bring in to trick the host and evade the immune system. And so your body can do a better job of learning what this protein looks like and making antibodies to it and to be ready to go the next time. 

We are seeing some drop off in circulating antibody levels for people that are now eight, 10 months after their initial vaccination. Mostly this is to be expected. We don’t have high circulating antibody levels for every virus our body has ever seen, that would take a ton of energy, it would be impractical. Memory immune cells are what we want to have ready to respond when your body sees this pathogen for real.

NCHN: Those B cells and T cells!

Gralinski: Yes! That’s really why you would still expect people to have that mild transient upper respiratory tract infection, potentially, after they’ve been vaccinated. If they get a high level of exposure, a lot of virus comes into their body and there isn’t enough circulating antibody to be able to fight it off immediately. You get just a little bit of replication, hopefully just in the upper airway, where it’s not going to cause too much harm to your lungs or anything. 

Then you’re able to fight it off because those immune cells are circulating, and they go, “Oh, I’ve seen this before,” and they’re ready. And they start producing more antibody and they can fight off this invading virus. 

NCHN: Speaking of mutations, what about that Mu variant? How worried should I be?

Gralinski: I am not that worried. None of the variants that we’re seeing are able to outcompete Delta at all right now. So outside of South America, you probably don’t have Mu, you probably have Delta, like 95, 99 percent sure you have Delta.

NCHN: Essentially, it’s kind of like in my garden, when I’m trying to get weeds not to grow. Instead, what I do is I plant vetch, and the vetch just grows like wildfire, and it outcompetes the weeds. This is Delta and Mu right now?

Gralinski: This is Delta and everything that we’ve seen so far.

NCHN: Do you worry about potential variants that might be more both virulent and spreadable?

Gralinski: I have definitely been watching to see if there are sub-lineages of Delta popping up and a lot of other people are doing surveillance work and watching this space and worrying and waiting and publishing lots of speculative kind of fear mongering pieces, in my opinion. 

Delta transmits really, really readily. It has out-competed all of the other lineages of SARS 2 that we’ve seen. Alpha (the so-called British variant that was prevalent in early 2020) seemed like it spread so quickly, and it took over the world in January, February. Well, Alpha is pretty much gone now, thanks to Delta. If Delta was more able to evade the immune system, that would be worrisome to me, but so far, we’re not seeing changes in that direction.

NCHN: Speaking of Delta, in other countries, we saw big spikes and then big drop offs. Do you anticipate that happening here?

Gralinski: I would really like there to be a big drop off! That would be, I think, a huge relief to everyone. It’s possible that we’re getting to that kind of inflection point at the top of the Delta spike. 

But I think it’s hard to say right now, one, because of less testing and reporting happening in the Gulf Coast area, where they’re dealing with Ida and all the fallout from that. 

Labor Day weekend complicating everything, where there’s less testing, during the weekend, but we saw articles yesterday about big lines going for drive thru testing in Wake County. Then we need time for any fallout from transmission that happened over Labor Day weekend itself. I think the next 10 or so days will be really informative. Delta seems to spread so quickly, it seems like we know a little bit faster, whether or not people are infected, whether or not they are symptomatic, if it’s transmitted or not. 

It really comes down to testing. Without testing we’re constantly running blind. And we need those levels to be very, very high, we need it to be easier for people to get tested, both through appointments, to drive through sites and at home tests.

I’m so grateful in so many ways that I don’t have kids to be worrying about during this pandemic. Seeing all of my friends deal with kids going back to school, and they haven’t been around a lot of other people in many cases and now you are. Colds are coming through, we saw a huge spike in RSV that we’re still dealing with. If your kid isn’t feeling great in the morning, is it nerves about going back to school? Do they have a cold? Or do they have COVID? Wouldn’t it be nice if you could take a rapid test in the morning? And have a little bit more confidence before you send your kid off? 

NCHN: Speaking of kids, you anticipated my next question: how can unvaccinated kids go to school safely?

Gralinski: Honestly I would say they can’t really, which is a horrible answer. I’m so grateful that we have mask rules in place, that’s a huge relief. Teachers and kids all need to be wearing masks. 

When you have kids eating together in more crowded rooms when you don’t have distancing rules in place, there can still be crowds. There isn’t any sort of rule that I’ve seen about what type or what quality of mask kids are wearing, or teachers are wearing or rules about teachers and other staff members being required to be vaccinated. It’s inevitable that there is going to be spread in schools and unfortunately, kids under 12 still can’t be vaccinated.

I think a lot of my friends are trying not to go crazy with stress, and the worry about all of this. I don’t blame them.

NCHN: What, what can you suggest that people do to send their kids to school safely?

Gralinski: I would suggest that the parents, any older kids, all the people around your kids be vaccinated whenever they can be. And then being conscious about masking and having good quality masks that are well fitted to your kid’s face.

NCHN: A good quality mask means what? A KN 95, or a surgical mask or a double layer cloth mask? What’s enough?

Gralinski: I would say at a minimum a double, triple-layer cloth mask, but if it could be an N 95, or a KN 95, that would be even better. I don’t know how many options there are that are smaller for kids’ faces. 

I think a lot of kids are really actually very good at mask-wearing, it doesn’t seem to bother them that much. And, you know, encouraging them, praising them for doing a good job with that and being attentive to those times when the masks do need to come off for eating or drinking. 

My husband and I were going for a walk through the neighborhood on Monday, and there were some, say, 10-year-old kids playing outside and they had masks on. The kids didn’t seem bothered at all.

The virus doesn’t relax, unfortunately, it’s going to seize whatever opportunities it’s presented with to spread and move on to a new host. And knowing that so many people are either asymptomatic or you can spread while you’re pre-symptomatic. Just feeling well isn’t a guarantee of anything, unfortunately. 

NCHN: So, here’s the real question: how much longer for all of this? We’re at 60 percent of adults vaccinated in North Carolina, then once kids are able to be vaccinated, we’ll be able to get shots into another 10 to 20 percent of the population. And then the rest of the unvaccinated seem to be getting it. When are we done with this? 

Gralinski: I wish I knew! 

In the spring, I really thought that by fall, things would be feeling much better. My husband and I were having a conversation about maybe we’ll be able to plan a trip. Obviously, none of that has happened. We’re just as stressed, if not more stressed, in some ways than we were at this point last year. 

I hope that we are nearing the peak of this crazy Delta surge that we’re seeing, and it will drop off. Vaccination numbers have slowly been going up in North Carolina.

We need a lot more of that, especially since we keep repeatedly seeing that while natural infection gives you some immunity, it’s really not enough. It’s not lasting. 

It’s definitely becoming clear to me that at this point, SARS 2 really is endemic, it’s here with us to stay. In that sense, it will become more like the seasonal flu that we have to worry about annually. Maybe it’s on health departments’ radars, there’s a vaccine that’s available maybe every year or every other year for either a booster or an update if the virus does evolve. 

If we realize that clusters are popping up in a certain locality, and maybe there’s a regional lockdown or a regional push for vaccination or regional reintroduction of a mask mandate, if people pay attention to the public health figures and you know, doctor’s recommendations, that could be really effective in limiting outbreaks kind of like we do with a flu or an RSV. Getting that type of surveillance is going to be something that needs to happen with SARS 2 infections going forward. 

At least I don’t have to explain why I work on human coronaviruses anymore. 

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Rose Hoban

Rose Hoban is the founder and editor of NC Health News, as well as being the state government reporter. Hoban has been a registered nurse since 1992, but transitioned to journalism after earning degrees...

7 replies on “COVID Delta variant Q&A with virologist Lisa Gralinski”

  1. Perhaps this was addressed and didn’t see it. I have a friend who insists he’s immune because he had Covid in December. Any thoughts around this issue? Thanks!

    1. The data show that people who had natural infections from COVID have waning immunity that, right around now, makes them susceptible to a repeat infection. Dr. Gralinski did note during our conversation that: “studies of healthcare workers where people had those early infections last year before we had vaccines available, and then even just one dose of an mRNA vaccine. Those people have the best antibody responses of anyone.” That research has been bolstered by a paper published in Nature in August, “Naturally enhanced neutralizing breadth against SARS-CoV-2 one year after infection,” that concluded, “The data suggest that immunity in convalescent individuals will be very long lasting and that convalescent individuals who receive available mRNA vaccines will produce antibodies and memory B cells that should be protective against circulating SARS-CoV-2 variants.”
      So, if your friend had COVID last year AND chooses to get an mRNA vaccine on top of that, he will have some of the best immunity out there. That Nature paper is worth a read. It’s fascinating. Two of the authors discussed it on the This Week in Virology podcast, number 796.

      1. What if you think you had COVID last year and then again this year, will the body have antibodies and memory B cells against SARS variants? Long lasting is what was stated and not short term. What is the short term based on and are more studies supporting long term? If you get tested for antibodies which ones would qualify you for not needing a vaccine? I also heard of the dangers of a vaccine after you had Covid, especially after 2 doses, can you comment on this?

      2. If you look at what Dr. Gralinski said above, she noted that some people who had asymptomatic cases of COVID and then vaccinated have been shown to have both N antibodies and S antibodies. Our bodies expend quite a bit of energy making antibodies, that’s why we have B and T cells, which carry the memory of a pathogen. In time, after an exposure to a pathogen, the body makes fewer antibodies, yet retains the ability to generate them and attack that pathogen (through B and T cells) into the future. Simply measuring the level of circulating antibodies 6, 8, 12 months after exposure to either an infection or to a vaccine doesn’t tell you enough to know whether about longer term immunity, which rests with the memory cells. That data is being generated as I write.

        As to “dangers of a vaccine after you had Covid,” I won’t comment, but I invite you to take a look at the Nature paper I cited above which goes into far more detail about the results of vaccination post-COVID infection. We’ve had several billion doses of vaccine given to people, many of whom would have had an infection already (this is more true in countries outside the US with less vaccine resistance). If there were a data signal about “danger” in this instance, I’m sure my media colleagues would have been all over it. I’ve seen no such signal in the data.

  2. Dr. Gralinski. You stated above. . “And knowing that so many people are either asymptomatic or you can spread while you’re pre-symptomatic. Just feeling well isn’t a guarantee of anything, unfortunately.”

    The WHO announced this year that the virus can not spread when you are asymptomatic.

    1. I would love to see that reference. Twenty months into this pandemic, it’s widely understood that there most definitely is asymptomatic spread, usually while infected people are in the prodromal period, ahead of the time when they develop symptoms. Most people acquire an infection where viruses incubate in the nose ahead of spreading to the lower respiratory system and really causing the hallmark symptoms of COVID. The nose is a great platform for spreading infection >a-choo!<

  3. I see many articles about the reinfection rates of someone who had Alpha Covid, but what about reinfection rates of someone that had the Delta variant? How likely is one who had the Delta variant in getting reinfected with Delta?

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