‘Likelihood of reaching herd immunity at this point is fairly low’: Epidemiologist

Suzanne Judd, Ph.D., Epidemiologist at the University of Alabama at Birmingham School of Public Health, joins Yahoo Finance to discuss the latest on the coronavirus pandemic.

Video Transcript

ALEXIS CHRISTOFOROUS: President Biden is pleading with unvaccinated Americans to roll up their sleeves and get the shot as new cases of COVID-19 spike across the country. Here now is Suzanne Judd, Epidemiologist at the University of Alabama at Birmingham School of Public Health. Doctor, thanks for being with us, and good to see you again.

Hospitalizations due to this virus have increased. Deaths are now also on the rise. What, if anything, is different this time than the peak of the virus that we saw back in the spring of 2020?

SUZANNE JUDD: This one seems to have a really high acceleration rate. So we haven't seen what we call epidemic curves in my field that are shaped the way this one is curved. That means that we're really seeing cases skyrocket rapidly-- much more rapidly than we saw in the summer, much more rapidly than we saw in December. This one just seems to burn through quickly.

In fact, some estimates guess that you only have to be in the presence of someone with a Delta variant for 30 or 40 seconds to become infected. That's much less than the 15 minutes we had last year.

KRISTIN MYERS: I'm honestly speechless to hear that. That's terrifying news. I know that we're seeing so many more people becoming infected with this Delta variant, and they are mostly unvaccinated folks. But just anecdotally, I feel that I'm constantly seeing more and more folks-- some that I know, some that I don't that are sharing on social media-- that have been vaccinated. And they're sharing that they've come down with coronavirus.

Is this because the Delta variant is more transmissible? Do you think that this provides any sort of evidence that the vaccine, while still effective, might not be as effective as we would like against this variant?

SUZANNE JUDD: Yeah, that's likely what we're going to find out. If you look at the different studies, there are different levels of effectiveness against Delta in different populations. The lowest level of effectiveness is 65%, which is still much better than 0%. And the highest is closer to 90%.

The other thing that you're seeing as you're talking to your friends and family that are having what we call breakthrough infections-- as we see larger numbers of cases, we think that roughly 2% of them are in vaccinated individuals. Well, as you start seeing 100,000 cases, 200,000 cases, it's just more likely you're going to come into contact with the 2% that have had a breakthrough infection.

So you probably will start meeting more people that have the breakthrough infection. You'll see asymptomatic testing increase again. And you may see people that get positive tests but have an asymptomatic infection. And so I know that is scary for people that have been vaccinated, but still, it's a very low risk. It's not that likely, but it will happen.

ALEXIS CHRISTOFOROUS: Of course, the backdrop to all of this is the young people-- those who are under 12 have not been able to get vaccinated yet. And school is going to be starting up in just a few weeks for millions of children. What would your message be to school districts who are thinking about, should we reopen and have school in-person? If the kids come in-person, should they be masked? What do you think would be most prudent?

SUZANNE JUDD: Masking would absolutely be most prudent. I know that there's a lot of hesitation for that. And my fear this time is that the people that can make the decisions to require masks just-- they won't want to because of what happened last year. I can say for my own team, for my own family, I'm having them mask even though it's not required by government or state authorities. Right now is the time that I would tell school administrators I know it's a tough decision, but you really have the chance to save students and their families, because it will spread rapidly in schools.

KRISTIN MYERS: So to that unvaccinated population, how does that really continue to weigh on the vaccinated population? Because I think whenever we talk about vaccinations, whether it's coronavirus or anything else, everyone says, well, listen, if you're vaccinated, you don't need to worry. I'm going to take on all the risk for myself if I'm unvaccinated.

But of course, as we see these cases really spreading, it seems to me as if these unvaccinated populations are really weakening our immunity, I'll call it, all around the country, and making it easier for folks that are vaccinated to get this virus. So how does that really play into our vaccinations and our ability to fight off this virus as a country, as a whole, that we still have these large pockets of folks that continue to remain unvaccinated?

SUZANNE JUDD: Yeah, that is a great question, and you're spot on. As we have large pockets of folks that are unvaccinated, that's what leads to the spread. And there are those 2% of the cases that are vaccinated individuals. And as the disease is allowed to spread, it could mutate again into a new form of coronavirus that everyone could be put at risk of again.

So absolutely-- the unvaccinated populations are what's driving this most recent surge that we're seeing. It's more reason than ever to get vaccinated if you're not vaccinated yet, especially in the younger populations where we know they're getting back together. There are concerns again, there are sporting events-- so large gatherings where this could really spread rapidly.

ALEXIS CHRISTOFOROUS: Doctor, finally, if there's going to be a subset of the population that will just never get vaccinated, if we don't reach herd immunity, is the virus something we're just going to be living with for the foreseeable future?

SUZANNE JUDD: It is. It absolutely is. Our likelihood of reaching herd immunity at this point is fairly low because of the fact that we haven't had great uptake on the vaccine. So when we're stuck with waiting for people to get infected and then the virus mutates, there are just going to be continual outbreaks.

It'd be better if they stayed outbreaks, which are usually contained, and they burn themselves out in two or three weeks, rather than what we're seeing right now, which is spreading across county lines, across state lines, and becoming epidemic again. That just means that the hospitals get overwhelmed, and our health system gets stretched thin when it becomes epidemic levels.

ALEXIS CHRISTOFOROUS: All right, Suzanne Judd, Epidemiologist at the University of Alabama at Birmingham School of Public Health, always good to see you.

SUZANNE JUDD: Good to see you.

ALEXIS CHRISTOFOROUS: Coming up next, a conversation with media mogul--