An Epidemiologist Explains What The Spread Of The Delta Variant Could Mean For Iowa

The director of the CDC last week said that the delta variant is a growing threat, especially to unvaccinated people. The highly transmissible variant appears to be gaining strength across Iowa, according to test results from the Iowa State Hygienic Laboratory. In each of the past two weeks, the delta variant accounted for more than half of positive coronavirus tests from Iowa, according to the Iowa Department of Public Health.

Dr. Melanie Wellington is an epidemiologist at the University of Iowa Hospitals and Clinics, an associate hospital epidemiologist and a pediatric infectious diseases specialist. She joined River to Riverto talk with host Ben Kieffer about the spread of the delta variant, what it means for Iowa and why vaccines may be key to stopping its spread.

This transcript has been edited for length and clarity.

Kieffer: "Talk about the delta variant. How does this change the outlook for controlling this pandemic with its rapid spread?"

Wellington: "The delta variant is one in a series of variants. One thing to remember is that we've dealt with these variants coming through before. Each one of these variants that sort of takes over the population of the virus happens because it's more contagious, more transmissible than the other variants that are out there right now. So it basically runs faster in the race until it finishes first."

"It has some changes in the proteins that attach to the human cells, and that makes it more efficient at infecting the cells. And whenever a virus is more efficient at infecting human cells, it becomes more efficient at infecting humans. And what that means is if a person has the delta variant and they come into contact with 100 people, they're going to infect more of those people than they would if they had the alpha variant or the initial strain that was isolated."

Kieffer: "How effective are current approved vaccines against the delta variant?"

Wellington: "As far as we know, they are still highly effective. And when I say as far as we know, that's simply because everything is constantly changing. We have good data looking at this. And the studies show us that the vaccines are still very effective at preventing this variant. There is a slight difference when you measure these things in the lab, but it's not at a level that would change the ability of the vaccine to work for people. It's sort of like the fine print on a contract is slightly different, but the contract still says this vaccine is very protective. So the vaccine is probably our best tool in combating this variant and all of the virus. And there are sometimes people who get infections even after they've been vaccinated with the delta variant or with other variants. But most of the time, almost always, people who get infected after they've been vaccinated have a much more mild case of disease."

Kieffer: "Let's talk about the unvaccinated. They haven't picked up that tool to battle this virus. What is the message for the unvaccinated listening?"

Wellington: "It's never too late to get vaccinated, and it's really important. The more that people are vaccinated, the faster we'll get out of this pandemic in general. And it's definitely super important with the delta variant because the more people are vaccinated, the less likely that variant is to come into our communities and cause trouble. And as a pediatrician, I have to remind everybody that the people who are zero to 11 years old can't yet be vaccinated. We don't have the safety data for them yet. Hopefully, we will soon. But remember, there are groups of people who can't be vaccinated. So if you're one of the people who can be vaccinated, it's more important than ever to go out and get that vaccine."

Kieffer: "And share the statistics here, because I've run into them on a number of articles this week: the number of hospitalized in the country with infections and the number of fatalities, these are people almost exclusively who have not been vaccinated, correct?"

Wellington: "Almost exclusively. There's always somebody who say breaks a leg or goes into the hospital to have a baby, and we test most patients who are being admitted, and we find that they may have evidence of infection that's not very active. So some people who have been immunized have a positive test, but that doesn't mean that they're having severe disease. Almost all of the people who have severe disease in the hospitals are people who have not yet been vaccinated."

Kieffer: "About 67 percent of American adults have received at least one shot (as of Friday, July 2), not quite reaching the goal that President Biden set for July 4 of 70 percent. About two dozen states will have reached that goal by July 4. It's worth noting, those are predominantly blue Democratic states. We know about the partisan divide here in this issue as well. Iowa is at, last I looked, 64 percent of adults have received at least one shot. How should we interpret that goal of 70 percent? Some states making it, some states, like Iowa, not quite?"

Wellington: "Seventy percent is a very good starting point. Ideally, we would have 100 percent of everybody who could be vaccinated, vaccinated, and that is really the overall goal. Seventy percent is a good starting point for where we need to be shooting for now. But we don't know for sure how much vaccination will really get rid of this. What we do know for sure is that everybody who can get vaccinated takes our country and our state that much closer to being done with this. And it might be protecting your grandmother or your baby, or somebody else may be protecting your baby and you can protect their grandmother. Vaccination is something that we do for ourselves and for our community. And it's more important than ever that everybody that can be vaccinated do so."

Kieffer: "At this point in the game, those who are not vaccinated are probably not fence-sitters. There could be some of those. But how do you address, most effectively, those who are unvaccinated? What is the tact you take to have the best chances of convincing that person?"

Wellington: "I alluded to one thing before, which is that any individual person may perceive themselves at low risk, but I guarantee you that someone they care about is at high risk from severe disease. And the only way we have as a society to protect those people we care about is to get everybody else immunized. And so if you don't have a child or grandmother or someone else who is vulnerable, then somebody you care about probably does. And by being vaccinated, you protect that person and you protect the other people in the community. And so I try to remind everyone that the vaccine here is critically important for individual health, but it's also important to take care of those people we care about who can't be vaccinated. The other thing I do my best with is get out there and answer questions about the vaccine, why it's safe, why we should be doing it, what particular questions individual people have, and sometimes we just sort of sit down and go through the data for how we know what's going on."

Kieffer: "Should people consider getting more than one type of vaccine? Does that increase their efficacy?"

Wellington: "Our best understanding right now is that one type of vaccine is sufficient, and that's where we know it's safest, as well as most effective. So I really strongly recommend get the type that's recommended for you or that's available to you and go with it."

Kieffer: "What do you see the outlook in terms of possibly restrictions — masks— needing to be re-imposed?"

Wellington: "If the virus continues to vary and it continues to take over and is at high levels of transmission, we may need those masks. So again, we need to do what we can now so that we don't have to go back there."

Kieffer: "Where do we stand in terms of if and when people will need a booster shot?"

Wellington: "So far, the studies looking at the vaccine immunity shows that it's lasting quite well. So no clear indication of a booster shot right now, but you can bet we're watching really carefully."

Kieffer: "And lastly, of course, the (July 4) holiday weekend ahead of us. The AAA predicting holiday travel will be at near pre-pandemic numbers this weekend. Some 47 million Americans to take to the roads, to the skies, to travel for holidays. Do you expect all this travel to increase the number of infections? Will we have some kind of surge and this further spreading of the delta variant?"

Wellington: "Probably. Every time we have people exposed to one another, we have an increase in transmission. So everybody needs to take every safety measure they can while they travel."

Kieffer: "OK, and specifically in situations where you're in close quarters and the air circulation is not the best."

Wellington: "Exactly. And in areas of the country where people have lower rates of vaccination, or if you're around kids or others who can't be vaccinated."

Wellington mader her comments on River to Riveron Friday, July 2.