Dr. Naor Bar-Zeev Answers Your Vaccine Questions


When will we have the cure to COVID-19? How effective will it be? Where will we get it?

Naor (to Johns Hopkins University).
Dr. Naor Bar-Zeev (Larry Canner).

Naor Bar-Zeev, an associate professor of international health and vaccine science and deputy director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health and a pediatric infectious disease physician and statistical epidemiologist, spoke on vaccine development July 29. Bar-Zeev, a Jewish local himself, spoke with the JT a little about his thoughts at this time.

This interview has been condensed.

What are your thoughts on the states’ response to safety concerns at this time?

It’s difficult to tell one is right and one is wrong. States are doing the best they can to optimize the response. The critical issue is contact tracking, tracing and isolation. And for the public, they need to be wearing masks when out.

What have you learned about a possible vaccine?

I’m not doing any direct work with development, I work on distribution once it is available. … Once the vaccine is available there will be an issue of making it available in large enough numbers to vaccinate everybody. There will be a high level of manufacturing [but] if we wait until [enough are ready] we will lose even more people.

We’ll be lucky if we have 2 billion doses by the end of 2021. Countries will have to sort how to distribute it and once that decision is made, decide on individual locations. And then they have to decide a good mechanism of delivery to children, or what about high risk communities? These will have to be engaged in the discussion, too. The vaccine has to be safe for the community. Whether that means make it available to shuls or schools or the local town hall; it’s not just a medical novel problem. Logistically, we don’t want people congregating.

Whether it’s possible or feasible is one thing but the [ideal] idea would be a shot in the mail. But we’re not quite there. We have to design delivery with the communities.
We have to make sure the vaccine is safe itself, too, and test the surveillance of that [to keep an eye on results].

And it will have to be adaptive to where the hot spots [of breakouts] are.

At the soonest, when could you predict a vaccine to be available to the U.S. population?

We have [vaccines] but they just need to be proven to be effective. So, that means a wide trial with all ages … Then it goes through licensing after all the data is collected. Then it can be manufactored. Realistically, it is hard to pinpoint, but it is unlikely that you can get one by the end of 2020. Maybe, for healthcare workers, by 2021.

Do you believe there will have to be a difference in dosages for older adults?

The main issue is older adults have the most responsive immune system. What is generally not safe may be needed to be effective for older adults. It would be wonderful to have one vaccine, but it’s possible we will need different ones for older adults, or more frequent dosages.

We also don’t know how long the vaccine’s effect could last, and if that could be different for different ages. If it wanes and we’re back to where we started that would be no good.

How reliable are the current testings on chimpanzees to the predictability of whether it will work with humans?

It is a necessary step. If it’s safe particularly to one biological animal similar to humans, meaning primates, it’s a good indication to move it to human trials. Then we need to demonstrate on humans that it’s safe and efficacious. The more it’s evaluated the more I will be comfortable to say it’s safe.

There’s only been 1,500 people vaccinated so far. We need many more people before I can say something is safe. So we’ll increase the number again soon, the next trials will vaccinate 30,000 each.

So the fact it’s safe in animals is a necessary step to get there, but the real results are in humans. The worst thing that’d happen is if [we went straight to testing on] people to cut corners, and that causes harm. That would be terrible for all vaccines, because people’s trust in vaccines would go down.

The population does have to be prepared learn from it.

What will that next phase of testing look like?

So we break it into Phase 1, 2 and 3.

Before Phase 1 of human trials, you have a whole bunch of experiments, then to animal testing.

We haven’t seen the results of Phase 2 yet, but are expecting to move to 3 soon. …. At the end of Phase 3, we can roll out the vaccines and begin a Phase 4. But when we get there, it also raises an ethical concern: What if the vaccine kills one in a million? Would you still give it to children?

These are not black and white questions, but there is a lot to consider.

What other challenges and questions like that must we consider?

So I already told you about distribution: who will get it first, how do we distribute it, and remember that equity does not mean the same. It means everyone will be protected equally.

But also, what if we have 1 million doses and people over age 50 require two.

And how are we affording it? And what if 70% is efficacious, or even just 50%? Do we still spend the money on it?

And what if there is no other option for a long time? The RotaShield vaccine in the ‘90s caused a condition in children, but it took 10 years for a new vaccine to come around.

You have these questions of what is practical versus the specifics of it.

Above all, though, people must remember: A vaccine is not the end all be all. It won’t make it go away. Particularly, not initially. Obviously we still need one. But. really, the idea of social distancing, washing your hands, being careful — this will still be crucial.

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