Animal Kingdom: COVID-19 Has So Many Hosts to Choose From

By now, almost all medical experts agree that COVID-19 is here to stay. It’s endemic. By now, many medical experts expect that humans will deal with COVID-19 the way we deal with other seasonal maladies such as the cold or influenza. Kevin Kavanagh, MD, agrees that COVID-19 is endemic (he said as much back in January), but warns that it’s still much more problematic than the cold or flu. Yes, the COVID-19 vaccines should ensure—as we face a fifth wave of COVID-19—that not nearly as many people will die from the disease as did this time during last year’s holiday surge. Kavanagh points out that “death is a pretty low bar for public health. Long COVID, mild [COVID-19] illness can cause devastations to our society.” These could come back to haunt society and overburden the health care system in the decades to come. There’s also the matter of animal infection. That means that the virus has innumerable hosts in which it can thrive and mutate, possibly into an iteration that can shake off the antibodies created by prior infection or vaccines in humans. For these problems, Kavanagh uses the compound interest analogy in banking. “When you look at it short term, it doesn’t seem like it’s doing much. But long term, this may be a real problem and a real toll to our society.”

Infection Control Today^®: I’m going to ask you to gaze into your crystal ball again, Doctor Kavanagh. You’ve written about a recent smallpox scare. And you’ve written many articles about the importance of booster shots. Why don’t we just start there?

Kevin Kavanagh, MD: Well, I think this virus is entering into a phase of becoming endemic. And we need to adjust our behavior. And one of those is this, we need to get a booster shot. Now boosters may actually be just a third course of the vaccine, and it may be part of the normal vaccine course that we’ll have in the future. But at least for right now, it is of utmost importance that people get boosters. If you look at some of the countries in Europe, some of these countries are highly vaccinated. For example, Iceland—also, Ireland and Gibraltar—where over 90% of the adults are vaccinated. Yet they’re going through huge surges. And what’s happened there is two

Kevin Kavanagh, MD

things: one is that these were some of the countries to first get the vaccine and to get their populations vaccinated. And unfortunately, they have not been very efficient at rolling out boosters. Some of them are just doing it now. And that’s allowed the COVID-19 virus to reemerge as immunity has waned. The other factor is when we talk about people who are infected with COVID-19. And whether or not you can get herd immunity, and you talk about numbers of vaccinations within the community, you need to realize that, to a large extent, it’s not homogenous on how people are distributed who are vaccinated and not. Those who are not vaccinated, tend to clump or gather together in their own social groups, which I like to sometimes call death cults because they go around spreading disinformation regarding vaccines. But in those groups and in those meetings and gatherings, you don’t have any herd immunity. They will readily spread the virus. And this is indeed one of the big problems that I think that we have. One is just because 90% of a country is vaccinated doesn’t mean that virus won’t spread and won’t have outbreaks, because we have whole segments of our society which are anti-vaccine. And that is I think posing a huge problem. And of course, as we’ve discussed before, you’ve got the problem of the virus being in animals and animal hosts. And you can get virus spread from people to animals, and also the reverse. Just last week, there was report of three snow leopard deaths at the [Lincoln Children’s Zoo] in Lincoln, Nebraska. And this was from COVID-19. And, also, there’s an updated report out of—I believe it was Iowa—where 80% of the whitetail deer were COVID-19 positive. And this follows a report which we discussed in Infection Control Today® back in August, where the deer from Illinois, Michigan, Pennsylvania, and New York had a positivity rate of around 40% for SARS-CoV-2. This virus unfortunately has also found animal hosts and that’s going to make it even more difficult to eradicate. I think at this point we need to plan to live with the virus and to adjust the way that we live so that we can do so as safely as possible.

ICT®: What is it with the snow leopards? You told me about a case of snow leopards getting it back in January.

Kavanagh: Yes. And the large cats tend to be very susceptible to the virus. And this includes small cats and pets. And it’s possible to pass the virus between the handlers and the people who take care of the animals. You know, these cats will cough and sneeze, they don’t wear masks, and they can easily spread the virus to those people who are feeding the cats or who are within a closed space, especially during the winter when they may be indoors. You know, they have indoor settings in the zoos where the caretakers are in with the animals. And as we’ve discussed many times before, this virus can aerosolize. Gorillas and other primates are very susceptible to the virus as are minks and guinea pigs. There’s a whole variety of animal hosts that this virus has besides man, which again, is going to make if very problematic in getting it eradicated. It’s also a little scary because, as you know, on an evolutionary scale, this virus doesn’t need people to survive. And so that means we need to really take this virus seriously.

ICT®: Does the virus actually kill the animals?

Kavanagh: Well, with the snow leopards and the larger animals, yes. On some of the smaller animals, they can get sick, but it may not kill them. For example, we haven’t heard of a large amount of deer deaths that have been occurring. The deer apparently live with COVID-19 quite well, but, yet rapidly spread it amongst the herds. And that’s actually very problematic, because if it finds a host that it doesn’t make sick, but yet it can mutate and change and then reinfect other animals and plus mankind, that is one of the worrisome scenarios that could take place. It’s something that we need to watch very carefully. At some point the Department of Agriculture may advise on culling the deer herd to try to decrease the numbers so that [humans are not in as close contact with deer] and it may not be as easily spread between areas and regions. That to me will be a warning sign that this may be something that is becoming more serious.

ICT®: As you’ve written for Infection Control Today®, the analogy between COVID-19 and influenza doesn’t pan out. COVID-19 is much worse than the flu. When you hear people say if we get 60% of the population with both doses of the vaccine, we’re at least not going to get the death rate that we’ve gotten before. Do you agree with that? And do you think that’s germane to the discussion?

Kavanagh: Well, I agree with it, but I’m not sure how germane this should be as a major goal, because death is a pretty low bar for public health. Long COVID, mild [COVID-19] illness can cause devastations to our society. And one of the things that frustrates me is that people really do not understand math. They don’t understand long-term effects. It’s mainly short sighted and their views are very simplistic. And let’s compare SARS-CoV-2 to smallpox. Smallpox will come into a community. It’s a DNA virus. It doesn’t mutate, doesn’t change very rapidly. And it will have a 30% fatality rate. Other members of the community tend to become immune, oftentimes for life with long-term immunity. It’s almost like—if you talk about banking—it’s almost like going out and paying for something in one lump sum. You pay for it. You get it over with. SARS-CoC-2 is more like compound interest. Very difficult to understand. It may just be a small toll in the beginning. And when I say small tool, I’m talking about a 1% fatality rate, maybe 5% or 10% disability rate, which is really a pretty large tool, but compared to smallpox, it’s not as large. But this virus is mutating, immunity’s waning, and it’s coming back year after year, wave after wave. I mean, who would have thought we’d be entering our fifth wave of this virus, which really makes the idea of herd immunity just becoming absolutely discredited. We’ve had too many people exposed to the virus. We have too many people [unvaccinated] And all indications are immunity is not long lasting. So, that we have to keep either getting boosters, or we have to keep up our anti-viral strategies, so that we can try to slow down this pandemic. At a minimum, we’ve got to keep our health care system from being overrun. We can’t have 14.5% increases in Medicare B premiums every single year. I mean, that’s at a minimum. And then we need to look at trying to get the rates of infection down low enough so that people feel more secure in going out and mingling in society, maybe going indoors, shopping, etc. And right now, we’re not there. People are still fixated on droplet spread. They have not upgraded ventilation to any big degree. At least in my region where I live, you don’t see a lot of people wearing masks. And there’s just a tremendous amount of misinformation, both on the severity of the disease, and the effectiveness of both vaccines and of wearing masks. This to me is a setup for disaster. And again, it gets back into more of the compound interest model. When you look at it short term, it doesn’t seem like it’s doing much. But long term, this may be a real problem and a real toll to our society.

This interview has been edited for clarity and length.