'Everything we do in medicine comes with some risk,': Preventive Medicine Specialist

Preventive Medicine Specialist & True Health Initiative President Dr. David Katz joined Yahoo Finance Live to break down the risks of the COVID-19 vaccines and what thisw means.

Video Transcript

SEANA SMITH: We want to continue this conversation. For that, we want to bring in Dr. David Katz. He's a preventive medicine specialist and also the president of True Health Initiative. Dr. Katz, it's great to see you again. The pausing of J&J's vaccination, let's talk about it. If you were someone-- some of our viewers may have already gotten the J&J vaccine, maybe they are scheduled to get it over the next couple of days-- how should you be looking at today's development? And does it at all change your opinion of the safety of this vaccine?

DAVID KATZ: Well, it does, Seana, and good to be with you as well. Because we now have information about a potential risk we didn't have before, we have to take that seriously. I think the pause makes sense. If you've already had the vaccine and you're a couple of weeks out, you're in the clear. One of my daughters got the J&J vaccine. My family basically signed up to get vaccinated when we could. We've now experienced all three because my wife got Pfizer, I got Moderna, and one of my daughters got the J&J vaccine.

And let's be clear. There are six reported cases. There have been over seven million of these vaccines administered. That's less than one in a million. Now there may be more, but it's still a very remote probability. So if you're scheduled for the J&J vaccine, yes, I think I would wait and let the dust settle from this. Either opt for one of the other vaccines or wait until there's a full investigation and there's a change in the recommendations regarding this particular vaccine. And in particular, this appears to be a risk in women.

And by the way, Seana, there's probably more to this story. It's actually a select group of women who are at risk of a blood clot formation from oral contraceptives, and in particular, the combination of oral contraceptives and tobacco exposure. And it relates to a genetic mutation and a particular element in the clotting cascade. I suspect that there are probably risk factors for this particular complication of the J&J vaccine. It's probably true that it's stimulating an immune response. But that's probably interacting with a native vulnerability. If we could identify that and all that work takes a little bit of time, then that population shouldn't get the J&J vaccine. There may be almost no risk for everybody else.

I think one of the critical messages here is that people need to understand everything we do in medicine comes with some risk. And anybody who tells you otherwise, you should run away in the other direction as fast as your legs will carry you. There's always some risk. But in a pandemic, every choice involves some risk. And if the risk related to vaccine is one in a million, but your risk of getting the infection and being harmed by that is massively higher, those are very, very tiny risks worth taking.

But right now, we do have other vaccine options. If you haven't gotten your vaccine yet and you're scheduled for the J&J, I would definitely defer. You know, keep yourself away from the virus in the meantime carefully, but I would definitely defer or try to get one of the alternative vaccines. And also good news that the bulk of the US vaccine supply is Pfizer and Moderna.

JARED BLIKRE: Doctor, that was a terrific explanation and breakdown of the situation, such that I don't really have follow-up questions on exactly this specific topic, but I do want to take a step back. Before, let's say, 2019, I didn't know anything about the vaccination process or what an efficacy rate was or what a good one was especially. How do these vaccines compare historically to what we're offered? Because my understanding is the Moderna one and Pfizer are quite different.

DAVID KATZ: Well, mechanistically, Jared, they are very different. This is a brand new approach to vaccination. It may prove to be the best way we've ever discovered, maybe lower risk, higher efficacy. It's really amazing that these mRNA vaccines are showing 95% and higher protection rates. Most vaccines that we rely on don't work nearly that well. You never get 100% protection. These are pretty darn close.

On the other hand, because they're new, frankly, I like the luxury of a long timeline to see, are there potential side effects? Do some side effects of vaccination emerge late? And we can't be complacent about that. The other thing to be clear on, unless you're going to wait a lifetime before administering a new drug or a new vaccine, you're never going to have a lifetime window to see what does it do over a span of decades.

So as I say, you need good science, good empirical evidence, but you always have to be prepared to learn more. If you study a vaccine in 10,000 people, that's a big study. But if it has a complication rate like the J&J vaccine may have one in a million, in a study of 10,000 people, you won't see one of those cases. You need to deploy it in millions before you see that. So it looks to me like the mRNA vaccines are delivering on the promise they showed in the studies, and so far, remarkably, free of side effects for the most part. But that doesn't mean they're perfectly safe. But so far, I've been very impressed. And again, I'm a beneficiary myself of the Moderna vaccine.

SEANA SMITH: Dr. Katz, I want to ask you. We have a graphic if we can pull that up on the screen, and it's showing UK versus US, the number of COVID deaths. And it shows that the UK far below where the US is right now. And I bring this up because the US is still giving two doses, while Britain is prioritizing one shot over the second dose here. From your perspective, do you think the UK has a lower COVID death rate because of this? Or is this due to something else?

DAVID KATZ: I think it's probably mostly due to something else. First of all, the B-117 strain that's now taken over in the US-- and that explains why we're seeing a surge in case counts in parts of the country-- it's more transmissible-- it actually originated in the UK so far as we know, which means they're probably through that hump. And we're just experiencing it now. So their trend is going to look good compared to ours now that that virus spread through their population. It's done infecting the vulnerables. It's clearly just now infecting the vulnerables in Michigan and other parts of the US.

But the other thing is recognizing the threat of the new strain developments, the UK-issued lockdown orders. And this was nationwide. So essentially, they went back to the more draconian measures that were so prevalent early in the pandemic. Sometimes you have to do that. The trouble with a pandemic, because the virus is subject to random mutation at a massive scale-- there's so many viral particles in circulation, perhaps a quintillion or more. And even on this show, you talk about the economy in big numbers. You never say a quintillion. But there may be a quintillion viral particles in circulation subject to random mutations.

So effectively, SARS-COV-2 just keeps moving the line. And we have to keep pace. We're sort of in an arms race to get through this before the virus outwits our immune system. So those intermittent measures to protect people from transmission during these surges are really important. And the UK engaged in that. And I think it has more to do with their policy responses than single dose vaccine. Frankly, it's very hard to tell. Should we get everybody vaccinated with one dose? Will that be sufficiently protective? Or will that confer only partial immunity, allow the virus to continue spreading, and actually favor the development of more mutations?

The best data we have, Seana, very quickly, out of Taiwan, there was a recent study in [INAUDIBLE] internal medicine looking at what seems to have worked very well in Taiwan. And there are few shining lights around the world that fared well in the pandemic. Taiwan is one. It was a combination, invoking personal responsibility, people engaged in their personal precautions. They used masks. They did social distancing and public policy measures to shut things down, basically in lockstep with the requirements of the virus, which is a moving target. So the UK responded to that moving target. The US has been reluctant to do the same.

SEANA SMITH: Dr. David Katz, it's always great to have you on this show. We really appreciate you taking the time to join us, preventive medicine specialist and also the president of True Health Initiative.