Dr. Tom Tsai, Senior Fellow at the Harvard Global Health Institute; Assistant Professor in Department of Health Policy and Management at the Harvard T.H. Chan School of Public Health, joined Yahoo Finance Live to break down his thoughts on the COVID vaccine and why Americans should get it.

Video Transcript

SEANA SMITH: We want to continue this conversation, specifically the news that we got out from Moderna. For that, we want to bring in Dr. Tom Tsai. He's a senior fellow at the Harvard Global Health Institute, also an assistant professor in the Department of Health Policy and Management at the Harvard Chan School of Public Health.

Dr. Tsai, it's great to see you again. So Moderna looking for FDA approval emergency use authorization to use its COVID-19 vaccine in children that are 12 years and older. I'm curious just to get your thoughts on whether or not-- or is this a game changer just to get kids vaccinated before they return to school in the fall.

TOM TSAI: Hey, Seana. Good to be with you. I really do think it is a game changer. It's built on the backs of very solid clinical evidence that shows almost 100% efficacy in terms of the severe symptoms and over 90% efficacy with mild symptoms. So the vaccine is safe and effective for this age of children.

And while we've been laser-focused on the Biden administration goal, over 70% of vaccination for adults, it's also important to make sure that we use the time that we have over the next few months to increase our vaccinations, once the vaccines are rolled out to school-age children, to really protect children and teachers as they return to school again in the fall. So having the extra options of Moderna vaccines, in addition to Pfizer vaccines and, I'm sure, others down the road, are all important tools that will help us to continue building the success of the last several months.

ADAM SHAPIRO: Doctor, what concern, if any, do you have about these reports, especially among teenagers, young men who've gotten their second dose of vaccine and then had some coronary issues. Help us understand what that's about and whether we should be leery of this.

TOM TSAI: I think it's always important to keep an open mind about complications or side effects that could develop with vaccinations, or any other medications or pharmaceuticals, that come out after the market. The [INAUDIBLE] data don't suggest that this is a clear and consistent pattern yet.

Many vaccines or some vaccines can cause immunologic reaction. So it's just important to stay vigilant, to continue to-- really at this stage right now-- is to continue to collect the data and make sure it still remains safe. But as of the moment, the data are still overwhelmingly clear that the benefits of the vaccines, even for young adolescent men of that age group, far outweighs any potential risk.

SEANA SMITH: Doctor, we have daily case counts trending in the wrong direction. They're back, about 20,000. We have deaths also rising for the third day in a row. Is this anything to be worried about just yet?

TOM TSAI: I'm always worried. I feel like that's been the constant frame of mind over the last year. And we have made a lot of progress, and I think we will continue to make progress. But I think it's also important for the general public to not let down their guard.

And yes, with mask restrictions lifting across many states and return to a sense of normal, especially as more and more individuals are vaccinated, we still have to remember that there are still pockets of individuals and pockets of communities that have not been vaccinated yet because of lack of access or other reasons.

So while we have made progress, it is not the end of the road yet. We have not hit that vaccination target yet. We have not vaccinated broadly enough and in younger age individuals and adolescents. So it's still important to stay vigilant.

And in some ways, it becomes a challenging risk calculation now. You may know about your individual family members and acquaintances, in terms of their vaccination status, but it becomes a little bit of an unknown in terms of people at work or in other social settings. So I think a dose of healthy caution is still really important when in [INAUDIBLE]

ADAM SHAPIRO: But Doctor, today is June 10th. We had an epidemiologist join us back in May who said June 10th would be when we would know, after the Memorial Day holiday, if all of us getting back together, masks off, that kind of stuff, would lead to a spike. Those numbers that Seana just referenced, might we be at the beginning of what that epidemiologist was worried about, starting today?

TOM TSAI: It could. I think what's challenging is that we think about these on a national level. And what I'm worried about is where the spikes are more locally. We are seeing an increase in hospitalizations in some more local areas, while nationally things have improved. In Boston where I am, we've made significant progress, less than ten patients with COVID in the health care system that I'm part of, which is a tremendous progress over the last several months.

So yes, I think in specific local context, there are individual spikes that are appearing, which is why it's important to not just look at the top line numbers. It's something called "Simpson's paradox." We can't just look at the average, because the individual states, individual counties, may tell a different story with more local spikes.

SEANA SMITH: Dr. Tom Tsai, always great to speak with you. Senior Fellow at the Harvard Global Health Institute. We look forward to having you back.