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Former Epidemic Intelligence Service Officer Explains Vaccines

A prominent epidemiologist with over 25 years of experience in developing vaccines, Lisa Danzig, M.D. spoke to the Jacket about the COVID-19 vaccines.


The Jacket spoke with Lisa Danzig, M.D. about COVID-19, vaccines, and what society might look like in the near future. Danzig is an infectious diseases physician and former Epidemic Intelligence Service (EIS) officer. She has spent more than 25 years bringing novel vaccines and diagnostics from the research stage to global markets, working in senior roles with Novartis, Grifols, and PaxVax. In the past year, Danzig has worked with various institutions, non-profits, companies, and governments around the world on COVID-19 responses and protocols, recently advising for the Academy Awards ceremony. The following is a transcript of the interview, which has been edited for length.

To what degree do you think the current vaccine rollout will impact the way we return to society in the coming weeks and months?

I think that vaccines are going to profoundly change the trajectory of the pandemic. Unfortunately, we don’t have equal access to vaccines. Therefore, communities with vaccine immunity aren’t necessarily going to get the most immediate benefit from a societal risk standpoint because there will remain hotspots. If you can get your whole community vaccinated, you’ll reduce the risk of explosive hotspots. It gives you a better chance of staying open once you reopen. 

Do you think that vaccines will give us a higher chance of being able to reopen safely?

They’re certainly going to help us accelerate that if we can get a significant amount of population immunity for the most vulnerable. Let’s remember what vaccines do: vaccines not only prevent infection, all of the vaccines available around the world are showing a significant impact in preventing death from COVID. 

We weren’t sure that the vaccines were going to impact transmission. There’s initial evidence from a study of Israel, also in the UK, that the mRNA vaccines are indeed interrupting transmission. So we’re optimistic. [But] nothing is 100 percent assured. If I may be prevented from getting symptoms, I may be prevented from dying from COVID. It doesn’t mean that if I get a bad strain, I can’t transmit it to somebody who’s either not vaccinated or [who], because of their medical background, wasn’t able to get a good vaccine response.

Is the lower transmission rate one of the vaccine’s effects on its own, or does it originate in the lowered symptomatic response that comes from being vaccinated? 

We don’t know. When considering the efficacy of the vaccine, the first thing is: how does the vaccine work? How soon does it work? What does it do? What does it prevent? 

We haven’t done all of those studies. We’ve got some indirect data that makes us hopeful that transmission is interrupted, which gives us hope that if we get enough vaccine coverage, that can accelerate control of the virus.

You’ve noted that there isn’t yet much data. What sorts of studies would need to be done and how long until they would be done?

Well, everything’s accelerated in COVID. The fact that the entire country of Israel got a vaccine rollout means they have data. On a population level, we can look at expected rates of transmission to know that the vaccine has an impact. Do we have a lower rate of spread in communities that are highly vaccinated versus others? You do a kind of zip code analysis … in something called cluster randomization. Let’s say you have two communities, one vaccinated [and] one not vaccinated. You would look at the difference of secondary cases. 

What is it okay to do once one has been vaccinated? Hypothetically, what are possible scenarios for a public high school?

[The vaccine] is not necessarily a free pass to run around and go back to [the] way life was before. I think we will be in a post-pandemic reality. 

I can take more risks individually, because if I come into contact with the organism, I’m not likely to die of COVID in a hospital. But I’m not sure it means classes [being] open without masks, or eating lunch with others who do not have immunity. 

Will the different efficacy rates of different vaccines affect the way that there is a transition into a fully vaccinated society?

The vaccines that have emergency-use authorization in the United States have pretty consistently high efficacy. So I’m not concerned about any differences around which vaccine people got. There are some differences with the other vaccines around the world. In particular, the inactivated vaccines that have been made — there’s one in India, there’s one in China — have rates of efficacy that range between 50 and 70 percent.  It may well be that those vaccines still prevent people from dying from COVID, but maybe not with the same high efficacy that all of the other vaccines have. 

So it creates ongoing risk. At some point, we’re going to [need] booster vaccines. So even parts of the world that didn’t get the best first response will probably do fine with a booster dose. 

Do you have any concerns about the reported issues with vaccines like AstraZeneca and Johnson & Johnson, which had issues with blood clotting?

There are certainly rare side effects. Most vaccines have some rare side effects. We have the good fortune to know what they are quickly because of some enhanced detection that was set up with this vaccine rollout, so we know that there were six cases of severe clotting after the Johnson & Johnson vaccine. And it’s similar to the types of reports with the AstraZeneca vaccine. We think it’s related to an immune reaction or an antibody against the platelets. 

Personally, [choosing between] a one in a million risk of a side effect for a vaccine versus [a] one in two hundred risk of dying from a virus, I would take the vaccine — especially if it’s the only one I had available. On the global level, I would absolutely take the J&J vaccine. I think they’re very good vaccines; they’ve demonstrated efficacy. 

You were talking earlier about less effective vaccines in India and China. Has there already been and will there in the future be a global impact of certain low effectiveness vaccines? 

It’s hard to know exactly what’s going on with those vaccines. Certainly, there’s room to improve. There are a bunch of studies ongoing. The UK is in the lead on these, but I think we’ve got some groups in the US doing mix and match studies. If your second dose is a different vaccine, how will we do? A booster dose of a different vaccine could give you good efficacy. I would expect, in a month or two, we’ll know.

I’m glad that we have any vaccine. So I’m less concerned about which vaccine. I’m concerned that everybody has access to something — even a 50 percent efficacy [vaccine] — as long as we don’t rely on it as our only tool. 

What are your thoughts on school reopenings, particularly in the Bay Area where things are going quite well with COVID-19? 

I’m optimistic. We’ve got rapid testing and vaccines. If we want to continue this trajectory, we need to remember that we don’t turn a switch and go back to the way we were. The virus isn’t last year’s virus against which the vaccine was made. The virus circulating now in some parts of the world is new and more aggressive, and spreads more quickly. And that’s our biggest threat. 

Has it been shown whether current vaccines protect against new variants? And is it possible that COVID-19 could keep developing itself against whichever methods we use to prevent its spread?

Yes and yes. Fortunately, the variants of concern that we know about have given us really encouraging data that our immunity will hold, but we don’t know for how long. So far, our vaccines are covering the variants. But there’s always the possibility of more mutations, and more viral evolution. 

Are there people for whom the vaccines wouldn’t necessarily work?

We’ve seen that there are certain patients on rheumatologic or cancer medicines — one of them’s called Rituxan — [who] have lower antibody responses to the vaccine. 

Is it possible to develop different vaccines that work better for people with those conditions?

There are some people that have defective immune systems, or are on drugs that suppress their antibody production. And for that reason, they’re unlikely to make the antibodies that the vaccine is asking their body to make. 

However, we’ve also got monoclonal antibodies. It was just announced that the Regeneron monoclonal antibody — [which is] given in four subcutaneous shots — can give a passive immunity that can prevent acquisition of COVID for three months.

What do you think is causing vaccine misinformation and hesitancy in general? Are there things we can do about it?

Our world is facing significant challenges. One of the most important things is trusted messengers, and we see how that got perverted. With social media hijacking our attention, there’s been a lot of active disinformation. We really need to immunize ourselves against disinformation as well, and be able to independently review information. 

It’s not just about vaccines. It’s politics, it comes in many forms; it’s our whole world. We need to help people … get back to the side of reality without judgement on how they were misled in the first place.