Expert weighs in on Johnson & Johnson's one-dose COVID-19 vaccine

The third coronavirus vaccine to receive emergency-use authorization from the Food and Drug Administration is being rolled out across the U.S. Medical trials found the Johnson and Johnson vaccine is 85% effective against severe illness. John Moore, a professor of microbiology and immunology at Weill Cornell Medical College, joined CBSN to discuss.

Video Transcript

TANYA RIVERO: Hello, everyone. I'm Tanya Rivero. Thank you for joining us. We begin with the nation's rollout of the third coronavirus vaccine to be approved by the FDA. In Louisville, Kentucky, some of the first shipments of the Johnson & Johnson vaccine are in this UPS truck, which will cross over the Ohio River into Indiana to make deliveries. Cargo planes will transport the new doses to hospitals and other vaccination sites across the country.

Medical trials find the Johnson & Johnson vaccine is 85% effective against severe illness. It is the first single-dose vaccine approved in the US. It's also easier to distribute because it doesn't need to be stored in extreme cold temperatures. Johnson & Johnson CEO Alex Gorsky told "CBS This Morning" the one-shot dose may ease a logistical burden in the unprecedented vaccination effort.

ALEX GORSKY: Knowing that we've got a safe and effective single-shot option that doesn't require extensive refrigeration should help that distribution, that kind of bottleneck that we've been seeing significantly in the coming weeks and months.

We're on track to deliver, as I said, 4 million within the next couple of days, 20 million by the month of March, and we'll have 100 million doses between now and the end of June. And again, what's really important to remember is that's 100 million people by the end of June can have one shot and be done.

TANYA RIVERO: Let's bring in John Moore now. He's a professor of microbiology and immunology at Weill Cornell Medical College. Professor Moore, welcome. Great to see you. So Dr. Fauci says all three vaccines are viable options, and not to worry about the lower efficacy of the Johnson & Johnson vaccine, take whichever one is available to you. Got it. Message understood. But in an ideal world, if you did have the choice between the three vaccines, would you choose the vaccine with the higher effective rate or the single-dose vaccine?

JOHN MOORE: I don't think people will be given a choice. I think they will be advised to take whatever vaccine is available at the site that they go to. I've not heard of a pick and choose option. So it's a hypothetical. And the advice that Tony Fauci has given and that Jen Psaki just gave on that segment you just showed is the right advice. It's best to be vaccinated by any of those three vaccines than to not be vaccinated at all. I think that's the critical message, and the public should not agonize at this stage over the details.

I mean, Johnson & Johnson are testing a second-- a two-dose version of their vaccine. It's in phase III trials at the moment. That might show-- I expect it will show-- that the second dose is beneficial. And I imagine in the months-- few months time, if it's necessary to give an additional booster dose of the Johnson & Johnson vaccine, that will happen. But at the moment, if you're offered a vaccine, take the vaccine. That's the key point.

TANYA RIVERO: Well, that brings up a very interesting point, Professor, because the two-dose vaccines, the Pfizer and the Moderna, both of them, after taking one dose, have a similar efficacy rate to the single-dose Johnson & Johnson. So could it-- is that the only difference, the point being that there are two doses of the same vaccine that just gives you a higher efficacy rate, and that would be the same result if you took two doses of the Johnson & Johnson vaccine?

JOHN MOORE: I suspect, as I just said, that a second dose of the Johnson & Johnson vaccine, if it's proven in the clinical trials-- and we need the data-- will be superior to the one dose. But that's down the road. We don't have that option at present. The two doses of the Pfizer and Moderna vaccines are necessary for maximized protection. And that's important if we deal with the variants that are going around, because the more stronger the vaccination protection you have, the more likely you are to be able to deal with virus variants, which we don't yet know is going to be a significant issue for vaccine efficacy, but let's assume that there could be a problem.

If there is a problem, the best solution to it is to take both doses. Then you're fully protected. And a lot of data is coming out of Israel, which has done a mass vaccination program. And they're looking at the infection rates literally by day. And you can see that, after about 14 days after the first dose, some protection starts to kick in. It doesn't in the first 14 days. So you can't get one dose of the Pfizer and Moderna vaccines and assume you're protected within a week, because you're not. So you need a minimum of 14 days before you see a protective effect, and then the magnitude of the protection increases day by day as the immune system kicks in. And it's boosted by the second dose. After that, you've got strong [INAUDIBLE].

TANYA RIVERO: So right now, we stand at about 7.5% of Americans who have received both doses of the vaccine. That still seems like a fairly low percentage of the population. Of course, if you then add to that all of the people who've had COVID and recovered, and presumably have some sort of antibodies that are protecting them, what population would need to be inoculated for there to be a significant change in the infection rate?

JOHN MOORE: Well, once we get into the high tens of percents, then I think you'll start to see vaccine and infection combined start to make the virus run out of targets. I mean, that's what the [INAUDIBLE] working definition of herd immunity is, that the virus finds it harder and harder to find people that it's still able to infect. But the best estimates are, you know, 60%, 70%, 80% of the American public would need to either have been infected and recovered or be vaccinated or both. And it's going to take many months to get there. We're not there yet.

The recent declines in infection rates are not due to the vaccines, or not mostly due to the vaccines. They're due to seasonal factors, and they're due to the winter surge, the holiday travel surge working its way through the system. So we need more time. We need much more time. And the projections of most Americans being vaccinated by July are pretty accurate. They're the best available information we have. And I think we should pay attention to that. Again, get the vaccines when you're offered them. And the more people that are vaccinated, the more quickly that the virus will run out of targets.

TANYA RIVERO: Professor John Moore, thank you so much for joining us. We appreciate your insight.

JOHN MOORE: Thank you.