Dr. Amesh Adalja, Senior Scholar at Johns Hopkins Center for Health Security joins Yahoo Finance’s Zack Guzman to break down the latest on the spread of the coronavirus, as the CDC states children can spread the coronavirus to members of their household.

Video Transcript

ZACK GUZMAN: --weeks, we have seen things improve here on the coronavirus front, at least when you track the average of new cases. Those have come down here in the US, and leading some to think that maybe we've moved past the worst of it. But there are new concerns tied to children going back to school. And new CDC report there highlighting the risks associated with the idea that children could spread coronavirus cases that they get at school back into the home. And that was the finding of a new CDC report that highlighted about 25% of children observed in that study did transmit cases back to those who were not in the school or non-facility contacts there, raising new questions about those risks as students do return to school.

And here to discuss that with us and more on the coronavirus front is our next guest. Dr. Amesh Adalja, senior scholar at Johns Hopkins Center for Health Security, joins us now. And Dr. Adalja, I mean, this is interesting to see the CDC come out with this, because we had seen reports, mainly from Politico, highlighting pressure from Trump appointees on Dr. Fauci to kind of stress here that children were not a risk in going back to school, at least when it comes to transmitting coronavirus back into the house.

I just want to read one of those emails that Politico did have from a Trump appointee, applying pressure ahead of Dr. Fauci's media reports. In that email that they published, they said can you make sure here, quote, "that there is no data, none, zero across the entire world that shows children, especially young children, spread this virus to other children or to adults or to their teachers-- none. And if it did occur, the risk is essentially zero." It would seem to seem to me that now we do have data that shows there is a risk here. And what does it say to you?

AMESH ADALJA: It tells us that we're learning a lot about this virus. And it has been true that children have been spared hospitalizations and deaths. And we haven't seen them sparking outbreaks. But there are circumstances when outbreaks can be driven by children, where they can spread it to individuals.

So it is important when you have schools, daycare centers, summer camps, all of those types of activities, you need to still have mitigation efforts. It's not guaranteed that just because you're having children there that you're not going to get spread. And it is important, as we have schools opening, that they put in place face covering rules for those children, because there is this chance. It's non-zero.

We know it hasn't been driving the outbreak. But it's clear that it does occur. And it is not true that it's something that you can forget about or not think. It has to be an important part of how you think about reopening schools and other places where children congregate.

ZACK GUZMAN: And how would you judge-- I mean, when you think about the statistics behind the study, obviously, preliminary, and kind of looking at this first, but, I mean, what do you make about the risks associated with that, if it is about a quarter of the spread here in the CDC observation?

AMESH ADALJA: In this study, it does appear that it's significant. A 25% attack rate is something that's around what we expect with adults in a household. For example, one adult may infect 25% of the other members of their household. That seems to be high. So we want to know exactly where did they contract this, what types of mitigation efforts were in place at those places where the children got infected, so that we can try and learn from this and minimize the spread that children might have.

Again, it's also important to remember, it is one study. And it's hard to extrapolate one study to what's going on in the entire world. And was there something special about these circumstances that allowed this to happen-- the age of the children, the activities that they were in, how they interacted in the household?

So there's a lot of questions there. So we have to be careful not to under-interpret this and we have to be careful not to over-interpret it. So we want more data on children and I think we're going to get it as schools open across the country.

ZACK GUZMAN: Yeah, well, at the very least, we are given the chance to interpret the data, a very scientific approach here, to think about what this means. And that, I guess, would kind of support the idea that maybe these institutions, whether it be the FDA or the CDC, are allowed to do their jobs here and not being pressured politically. I know that there have been fears about that happening, especially as we get close to maybe getting one of these vaccine candidates approved for Emergency Use Authorization.

But when you step back and look at the Trump campaign itself, interesting to see them denying or defying, I should say, the directive in Nevada, as they hosted an indoor rally there, and really looked over the fact that Nevada doesn't allow more than 50 people to gather indoors right now. They said they chose some outdoor venues that were declined by the governor. But what do you make of that, landing on a manufacturing plant, the president speaking indoor at a rally and the risk-- and the risks tied to that during the pandemic?

AMESH ADALJA: It's another example of this mixed messaging that we've seen from the very beginning of this pandemic, where on the one hand, they're underplaying it, behaving as if we're not in a pandemic. But then, as we heard on the Woodward tapes, talking about the fact that they know that this is severe, that it is worse than influenza. And I think that makes it very hard for the general public to know how to behave.

And we know that indoors, the spread of the virus is enhanced. And we've seen already with political rallies, like the one in Oklahoma, that cases can occur. So this is something that if you can do this outdoors, if you can do social distancing, if you can have a face masking policy, you can make this safer. We know we can't get the risk down to zero.

But I think it is careless to have these types of large gatherings indoors when there are other alternatives available, especially when it is something like a political rally. And it seems more to make a political point than it actually does to try and mitigate the spread of this virus. And I think this, again, is just poor leadership that we've seen from the very beginning of this pandemic from the highest levels of our government.

ZACK GUZMAN: Yeah, I mean, obviously, it's not just the political rallies here, as we were discussing on the show last week, some stadiums allowing fans back in. So there's a lot of measuring to do in these next couple of weeks to see where cases go, particularly where these things were allowed to move forward. But until we get a vaccine, that seems to be the cycle that we're in, is watching the data, looking at where these hotbeds are of new cases.

But on that front, the vaccine front, interesting to see the updates there, as Pfizer's CEO mentioned that it could be possible here for Americans to get those COVID shots before the end of 2020. I'd be curious to get your take on that timeline here as, again, all of these vaccine candidates would need to get FDA or Emergency Use Authorization here before they're rolled out to the public. But what do you think about that timeline to actually get them to those first-line workers before the end of the year?

AMESH ADALJA: I think it's in the realm of possibility, if everything goes perfect in Phase III clinical trials with the Pfizer candidate or some of the other candidates, that we can get a limited Emergency Use Authorization before the end of the year for maybe health care workers, high-risk individuals. It's not going to be as if the general public has access to this vaccine, probably well into 2021. So I do think that we can expect a trickle of vaccines, several hundred thousand doses, maybe, that can cover some of our health care workers who are at highest risk. But this is something that we're going to be fighting for the most part without a vaccine as we get into 2021.

ZACK GUZMAN: Yeah, and beyond just those big CEOs, I mean, they're working with other companies here to really roll those out. And that becomes the next question, is how many-- how much manufacturing capabilities here can feed these vaccines to get them out across the world. The "Financial Times" recently spoke with the CEO of the world's largest vaccine manufacturer based in India.

And he laid out the timeline, that it wouldn't take until about-- it would take until about the end of 2024 to have all of the vaccines needed to get out there across the world. It's going to be until 2024. So, I mean, when you think about that, how long stretched would the vaccine rollout be in getting it into the hands of all those people out there that actually need it and you can reach the herd mentality that needs to be achieved?

AMESH ADALJA: We know it's going to be a big challenge, especially in resource-poor countries. We still have problems getting measles vaccine into people's arms or polio vaccine into people's mouths when you think about the world as a whole. So I do think we are going to be rolling out this vaccine program, if you think about it globally, for several years. I think in the United States, hopefully by the end of 2021, we have enough of the herd-- enough people vaccinated to cross the herd immunity threshold.

But vaccine delivery is a very complicated matter. And some of these vaccines, they require two doses and they require extreme cold storage, like minus 70 degrees centigrade. That's very hard to do when you're thinking about places where they don't have electricity that's standard. So this is going to be one of the most daunting vaccination programs that we've ever had, probably in history.