FordhamNotes · Troy Tassier on Vaccines and the Covid-19 Pandemic

Full transcription below:

Troy Tassier: If you think about an infectious disease, it shouldn’t matter if you’ve got a lot of money or not, right? It shouldn’t matter what your race or your family background is. We all have roughly the same DNA, we would think that we would all be equally afflicted by something like the current pandemic. But that hasn’t happened, and it hasn’t happened in terms of health, and it also hasn’t happened economically.

Patrick Verel: The vaccines are here. This month, residents of long-term health care facilities, and frontline workers, such as nurses and doctors, began receiving the first COVID-19 vaccine approved by the FDA. And a second vaccine is expected to be rolled out in the coming weeks as well. That’s the good news. The bad news is the coronavirus pandemic will still be with us until spring, as authorities work to distribute the vaccines to the nation’s 300 million-plus residents, some of whom may not be receptive to taking them. Just as the pandemic forced us to adjust to a reality that once seemed unthinkable, ending it will require a coordinated effort unlike anything we’ve experienced since World War II.

Troy Tassier, a Fordham professor who studies economic epidemiology, has been focused on the pandemic since it first struck the United States in March. He’s dismayed by the recent exponential rise in infections and deaths but says there are some lessons from the spring that can serve as a guide for going forward. I’m Patrick Verel, and this is Fordham News.

PV: Talk to me about March. You cut four videos to try to help the public understand new concepts, such as flattening the curve. Knowing what we know now, what worked, and what didn’t?

TT: You can actually, if you look at the shape of the takeoff and how quickly the cases rose, what you can see is very, very quickly, within a week or two after we, say, shut down things in New York, just as an example, that the rate of increase got smaller really, really quickly. And it was still going up exponentially, but it was a smaller exponential growth if that makes sense. So if you just think about this for a minute, right, if the reproduction number is something like four, then you’re taking four times four and getting 16, and then 16 times four and getting 64. But if you can get that down to two, it’s still going up exponentially, but it goes from two, to four, to eight. So the growth still looks horrible, but it isn’t as bad as it would have been if we had just let things run its course.

PV: You’ve been able to learn some really interesting lessons using anonymous cell phone data, right?

TT: Yes. So there’s this company called SafeGraph, and what they do is they essentially collect data from cell phone users. And it aggregates this cell phone mobility data at what’s called the census block groups. And so they take all of this data, they aggregate it so that it’s anonymous to numbers of people within these census block groups, and then they make this data available. What SafeGraph did as a public service, was to anybody that was doing research on the coronavirus, they just made the data freely available. And so what you could do, is you could look around, you could take this data, and then you could look in specific areas, and see what the change in people’s mobility was relative to the same time period a year ago. Right? And what we found was that once the epidemic happened, and there were these stay-at-home orders, and people were fearful of contracting the virus, that this mobility measure fell off a cliff.

What you also see is that people that were in geographic areas that tended to be poor, that tended to have low wage jobs, presumably people that would be working in grocery stores, or other, maybe janitorial tasks that still had to be accomplished. Areas that had people with these types of jobs, their mobility didn’t fall nearly as much as the more affluent areas. So essentially, folks that were well-off, frequently they were able to work from home. They were able to order out and get their groceries, they didn’t have to go out and put themselves at risk. Then you can think about this as not being surprising then when we see that these poor neighborhoods also were the hardest hit by cases and by deaths. It’s not only that these populations maybe don’t have access to healthcare, maybe don’t have access to testing, but they were in some sense, it’s maybe a bit too strong of a word, but they were close to forced to go out and deal with the pandemic in ways that other people weren’t.

PV: So in theory, a virus doesn’t distinguish between black, white, rich, and poor. And in reality, it sounds like something like this proves that it actually matters a great deal.

TT: It does. If you think about an infectious disease, it shouldn’t matter if you’ve got a lot of money or not, right? It shouldn’t matter what your race or your family background is. We all have roughly the same DNA, we would think that we would all be equally afflicted by something like the current pandemic. But that hasn’t happened, and it hasn’t happened in terms of health, and it also hasn’t happened economically. The other piece of this is if you look at the economic data, and just something as simple as unemployment rates. If you look at the groups that are in the top 20% to 40% of income earners, that they have almost recovered to exactly where they were in January. But the people in the bottom 20%, they’re still experiencing employment rates that are around 20% lower than they were in January.

PV: Now that we finally have a vaccine on the horizon, what do you see as our biggest challenge?

TT: One is, as long as people feel safe about taking the vaccine, making sure that people actually go out and do take the vaccine. So as I think most folks know, there’s a growing anti-vaccine movement, both in the US and across the globe. I think one of the reasons for this is that there’s a pushback against things like the measles, mumps and rubella vaccine, is because in the United States, at least, the cases aren’t that high. So it’s fairly riskless to say, “I’m not going to get my kids their measles shot.” Because if they don’t get the measles shot, the probability of them getting measles is pretty small, just because everybody else is doing their part in getting the vaccine. And with something like the current pandemic, this vaccine is, I think, going to be very crucial to ending the pandemic, or at least greatly lessening this pandemic.

And so we’re in a different world than not wanting to take my MMR shot because I distrust vaccines, and I’m probably not going to get sick anyway. The second thing is that the vaccine by itself probably won’t end the pandemic. And there’s been some interesting discussions recently about this thing called the Swiss cheese model of public health. If you think about a block of Swiss cheese, it’s got holes in it. And imagine taking a bunch of slices of Swiss cheese that all individually have holes in them. And if you take all those slices of Swiss cheese and stack them on top of each other, you can’t get from one side to the other. Because even though there’s holes in every individual piece, you can’t get all the way through the block, right? Because the holes don’t all align perfectly, right?

And so the idea of the Swiss cheese model, is that there probably isn’t going to be one magic bullet that is going to end this epidemic. And so what we have to do is think about all these public health measures, like wearing a mask, social distancing, limiting mass gatherings, all as these different layers of Swiss cheese. Because none of them individually is going to fully protect you from being infected. I can wear a mask, but maybe it’s a little bit crooked, so there’s an air hole that allows me to breathe out or breathe in, right? I don’t go to large gatherings, but maybe if I go to a gathering that has five people, that’s enough to have me infected, right? And it’s the same thing with the vaccine, right? We would like to think that the vaccine is this magic bullet, that 50% of the people take the vaccine and the epidemic is over, but that’s probably not the case.

And we’re still going to have to take these other preventative measures, because not everybody is going to get vaccinated, and the vaccine isn’t going to be fully effective in everybody, right? So for instance, the people that are most vulnerable to dying from influenza are the people for whom the influenza vaccine is least effective, right? So people older than 65 are the ones that, if someone is going to die from influenza, those are the folks. But the vaccine is much less effective in someone that age than it is in someone my age or your age. And we don’t necessarily know yet, but my expectation would be that it will be similar with this vaccine. So we’re probably still going to have to wear masks, we’re still going to have to be careful about large groups of people. And we don’t want to think about this vaccine as a magic bullet that is just going to make everything better, because it most likely won’t.