COVID-19 Vaccines – Behind the Scenes | Vital Science: S2, E04
Welcome back to Vital Science, and the final installment of our vaccine series. If you missed any of our previous episodes, I encourage you to visit our Vital Science homepage criver.com/vitalscience, and download these timely and insightful conversations. You can also find us on Apple Podcasts, Stitcher, Spotify or anywhere you access your favorite podcasts. Much has transpired in the past four months since we welcomed Dr. Sarah Gould to the show.
When we first started our series, the race was on, to find a safe and effective vaccine for COVID-19, and now it appears we might be reaching the finish line. Our senior principal scientific advisor and vaccine expert returns today to talk about the candidates that are currently in clinical trials, what needs to happen to gets these medicines to the global population, and what we can expect in the months to come. With that, I'll turn things over to Chris and Sarah. - We are back with Sarah Gould Senior Principal scientific advisor with Charles River and we're here to talk about the progress of the COVID-19 vaccines. Sarah, welcome back to Vital Science.
- Thank you, thank you for having me back. - Absolutely. So let's just jump right into it. Can you give us that high level overview of where we stand right now with these COVID-19 vaccines? - Yeah, sure, I'll do my best. Well, I mean it's amazing really what's happened when you think about it, there are about 155 or so vaccines in the development pipeline at various stages. And actually in terms of phase three, which is like we're coming to the end of the development, 10 vaccines which is amazing in the very short space of time.
And this is quite a timely discussion because most people will have seen in the press the statements by Pfizer and Moderna about how their vaccines are working. And these are two vaccines that are in phase three of the clinical trials and they seem to be working extremely well with an efficacy readout of around, 90, 95% which is really good news. - Yeah, it seems like a lot has changed since the last time we spoke, in a good way. You mentioned 10 vaccines in phase three trials right now. What are the different technologies that these companies are using to make these vaccines? - Yeah, so although vaccines all sort of work in the same way, and I think we've heard Tina discussing how they work in terms of generating an antibody response. That's what their aim is, to try and generate those antibodies that will help fight against the virus.
They're all sort of made in a slightly different way using different technologies. So well, again, it's been in the media about MRNA so that's the platform and the technology that Pfizer and Moderna are using. But there are other technologies, older technologies, what they call like an inactivated virus is also being developed. So that's when they take the virus and they sort of mash it up and kill it.
So it can't have an impact on you in terms of causing an infection but of course it can help generate the antibody response, which is what you want for it to be effective. There are other technologies, we've got very clever these days in terms of just being able to isolate the specific antigen or a protein. And so, there's a couple of vaccines also in phase three that are generated like that. And there's some other, what they call vector vaccines that they're also using, where they're sort of engineered and they've added this specific antigen. So, they're very specific to the needs for fighting against a virus, and hoping to have higher efficacy because of that specificity. - In the last couple of episodes, we've discussed historical vaccine development versus today's current technology.
Will this vaccine mimic our annual flu vaccine? - Mimic, well in terms of any vaccine, it'll work the same as any other vaccine that we take, and that's used to prevent infectious diseases. The flu is special in terms of as we talked last time, it tends to mutate. And that's why we end up having to have this yearly flu vaccine. We really don't know with COVID whether that will be the case or not. Again, there's been some discussion and people may have seen, this notion that the COVID may be mutating. Now we don't know whether that's going to impact on how the vaccine works, that's currently being generated whether that mutation may be in a place that's irrelevant to that in which case the vaccine stays, carry on working.
So again, the challenges for everybody is that this is a very new virus so we don't really know that much about it. So we're learning as we go along, which is quite unusual really, in the development of vaccines, when you're in consideration, this is a pandemic situation and we need a vaccine now out there, so we're learning a lot. But I like to hope that it's not going to have to be yearly. What would be great if we can have one vaccine, it works and lasts as long as possible without having to be re-vaccinated.
We do know that to get the vaccine to work, it looks like most of those current vaccines that are currently in phase three are going to be administered via the arm, sort of intramuscularly into the arm and that they will need two injections probably to work in the initial phase. - Well, I think we're all hoping that it is gonna be a one and done type of vaccine. In the news we have heard about, I think at least two clinical trials that were temporarily paused. What does that mean? - Yeah, see when they're running the trial they're monitoring the patients and checking for safety and recording any what they call adverse events.
So one or two of the patients had what's called an adverse event. And when they don't quite know what it is, they have to understand it. So these can sometimes just stop the trial, so while they're just working through what happened. Was it vaccine related or not? What's the consequence of that? So it's a caution when they do that. So they stopped it because it wasn't sure whether it was a vaccine related effect or not. And that it's often very difficult to know.
So that's why, and then they stopped it. And then once they'd been through the data and understood everything, they said, "No, it's okay we can carry on." - And obviously safety is their focus for that. - Absolutely, so it's better to be cautious and to stop the trial and to check through thoroughly rather than just allowing it to go on and other patients end up having adverse events when it could have been prevented. So, yep, it's kind of standard.
What's probably not standard is that those sorts of things don't usually enter into the media, but of course with COVID the spotlight is on, the vaccines and everybody's watching every move (chuckles). - Yes every day. And speaking of that, we've discussed the shortened timeline for these clinical trials for this vaccine.
Can you reiterate to the listeners how safe and effective that is, with the shortened timelines? - Yeah, of course. I mean, shortening the timelines. It's an amazing amount of effort that the manufacturers have had to put in. Some of the reasons why that's been shortened is that they've been doing things in parallel. In terms of safety, they're not going to let the level of, how can I put it? Excisions in terms of that safety level reduce. So safety is maintained.
And you can see that by the fact they stopped those clinical trials. They didn't just let them go on, that was standard procedure and they stopped the trial. So safety is very important, and that's why the phase three clinical trials have gone ahead. And the phase three clinical trials have a number of patients that need to be enrolled in the thousands as you've probably, again that's been shown in the media, there's, I don't know for what, Pfizer or Moderna. They're looking at dosing up to 43,000 patients to see.
So the authorities, the regulatory authorities will be assessing the data and they won't let any vaccine manufacturer go forward without having that phase three data. - And of those 43,000 in this example, that's general population, different age groups and races. - Yes, the criteria will be set out in the clinical trial design. Usually it's between, usually male, female between 18 up to maybe 60, 65. I don't know the details of the criteria but I mean, it is available. You can look under clinical trials and they have the outlines of who the patient populations are.
They will probably be going into more healthy volunteers at this point. They would have screened out anybody with underlying issue because obviously they want to make sure that there aren't any adverse events occurring. So that they tend to use healthy volunteers at this stage. - Okay, so we have those two drugs in phase three, with really good effectiveness that we've seen from the news. I think the question everyone's wondering is how long will it take for the general public to be vaccinated after the vaccine is officially approved? - Yeah, that's a very good question.
Yes, and as you say everybody wants to know that, I think to be realistic, it's going to be a rolling strategy. I think they're already, I mean the regulators need to review all the data and they're going to do what's called a rolling submission. So I think that some of the data has already been submitted to the authorities and they'll be looking at that. And then I think in terms of who gets the vaccine, I think from what I can understand they're going to consider the roll out as we do with the flu strategy. So those people who are more vulnerable or the healthcare workers, I think we're going to be in line. And I also think that they might use an Emergency Use Authorization, in the first instance, again for health workers and probably patient populations who are susceptible, a bit like the flu strategy.
So it might take a little bit of time. It's gonna take a bit of time for everybody to get the vaccine. - And on the news, we're hearing about emergency approvals, is that different than a regular FDA approval just so we can get it into the general population faster? - I think that when they use the Emergency Use Authorization it's usually limited in terms of who will receive that vaccine. So I think, there has been circumstances when vaccines have gone under that emergency use but it's very limited in population.
We could actually look at Russia, I think Russia which, in a way rushed through, they licensed on after phase two data which for many authorities, they considered that too early but actually they limited the patient population who will receive the vaccine at that point. I think they limited it to the military and maybe healthcare workers. And then they are continuing to look for other patients and continuing with their phase three trial. So I think the authorities will be looking at doing something very similar. What normally happens is all the data is put together, I mean it's a massive collection of all the information that they'll need from the manufacturing side, from the pharmacology side, from the safety side, from the clinical side are put together in a dossier and that is reviewed by the regulatory authorities such as the FDA or in Europe, the European Medicines Agency.
They're at not at that stage in development for all the documentation to be ready for that review. So they may have submitted some aspects of it already to the authorities. So it may have started, but yes, I mean the authorities are gonna have to review all the documentation. The fact that they're still in a clinical trial and it's still running and they're still enrolling.
So they haven't enrolled yet the 43,000 patients at this point that data's is being generated now. - Let's start with the Pfizer vaccine. It has to be stored at minus 80. I mean, obviously there's gonna be some challenges with the distribution of that. Not only with cold trucks but just the availability of minus 80 freezers at all of these hospitals, whether you're urban or rural. Can we talk about some of those challenges? - Absolutely, there will be challenges.
I think for the vaccine that needs to be stored at minus 80 where obviously minus 80 refrigerators are not available say particularly at your local doctor or your pharmacy, they're not gonna have a minus 80. And even the transport has to be considered. So, I think there's some logistical challenges there that are being considered. And I think Pfizer has been addressing some of those. I've heard that they've got some suitcase size shipping containers specially made that are minus 80, et cetera. But yeah, that's a challenge.
I guess the good news for Moderna is the fact that, as I understand, they don't need minus 80, they need a fridge like temperature about four degrees centigrade. So, there's definitely always some logistical challenges with vaccine distribution. And then of course this vaccine has to be distributed globally really to everybody. So that also includes hot countries. So yeah, there's gonna be some challenges that need to be addressed.
- Now we're talking about Pfizer and Moderna because they're in the news. So there's a good chance in 2021, we're gonna have two, maybe more vaccines available for the general public. How will we know which one to take? - Good question, we may not have the choice.
I think it's going to be dependent on each individual country. Some countries depending on how their healthcare system is set up, it will be the decision of the government. So for example, in the United Kingdom which has the National Health Service that will be under the charge of the government probably as to which vaccines they're going to buy, and how that will be rolled out to each sort of healthcare authority. I think pretty similar in France, I can't speak for the USA. So yeah, I think it's gonna be managed often at the governmental level. The good thing is that there are a number of vaccines, so in terms of supply, that's great.
And the key here is not which vaccine, we want a vaccine that works. So as long as they work, so as long as they all work it doesn't matter which vaccine you get, and they're safe. It doesn't matter which vaccine you get. - Let's talk about post vaccine approval once it's out in the general public. I think we mentioned in earlier calls that the volunteers on the trials are typically watched post vaccine for about two years.
Is that right? - Yes, absolutely. They will continue to be surveyed and monitored. And also the clinical trial readout, they'll be also looking for the duration of the antibody effects. So they'll be wanting to see how long this effect lasts. So yeah, that data will continue to be generated. So, although the vaccine will be licensed they'll have all the key short-term safety data and their fixie data.
And then they'll want to understand, does the antibody last for a long time? Do we need to re administer this vaccine in a year's time in two years time? The same will be when, with the vaccine that's licensed. There is also a monitoring that goes on for any vaccine that's licensed. There is what's called a Pharmacovigilance that monitors what's happening with the vaccine. So if you go to your doctors, you have a bad reaction you should go immediately back to the doctor and that will be reported.
- So when the vaccine becomes available, I think that next big question on everyone's mind is, when will things get back to normal? Will we still need to wear masks and practice social distancing? - Yeah, absolutely (laughs). I think we're all dying to know the answer to that question. And of course nobody can answer that question.
But we do know that the vaccine will help with that to return us to a normal way of living. But what we need is the roll out of that vaccine to the majority or a significant number of the population. So as you've just heard, we're not going to be able to vaccinate everybody straight away, there's gonna be a roll out of the vaccine. So, you're gonna to have to wait until really a large number of the population have been vaccinated to be able to return completely to normal. - And finally Sarah, you mentioned before Pfizer's vaccine is 90% effective.
Moderna is reporting 94.5 effectiveness. Dr. Fauci said, he'd be happy with a drug that's 50% effective. So this far supersedes what he was looking for originally.
It's really good news. And my question to you is, are you gonna take this vaccine? - For me personally, yes, I'm going to take this vaccine. I'll base that on knowledge that vaccines overall are very safe, and providing of course that there is no safety issues. It's always possible to actually access some of the data.
So the authorities will publish some of the data. So you can access that. Obviously, sometimes that data is difficult to understand, but for me, I will be in the queue taking the vaccine. And there is information that can be obtained that I know there's lots of things going on in the media at the moment, and we know that sometimes the facts are not necessarily the right facts that get printed.
So, a good resource where people can access information is to go onto the website by the World Health Organization. So I think it's who.int and they have specifically created topics on COVID.
So you can isolate that, including, easy to understand for the public, even to how to manage the information that you're receiving from all over the place and the media, et cetera, there is a, it's called the MythBusters. So you can have a look at that, I think that's a really good resource. - Thank you Sarah for joining us again on Vital Science and keeping us current on information that is so topical and obviously very valuable to the public. We'll be sure to link the resources you mentioned for our listeners in the show notes.
And I'm glad that you're able to speak with us again. - Well thank you very much for inviting me. It's been a pleasure and well, I think, we've got some good news at the moment which is great. So it's all moving in a good direction. - Absolutely, thank you.
- Thank you. (upbeat music) - When we read the headlines, it can be easy to forget how remarkable it is to get not just one, but numerous vaccines this far into development in a matter of months, as well as the significance of reporting such high efficacy rates in the trials. All throughout this series, we've heard scientific perspectives that have created context for us.
As we all await the much anticipated protection against COVID. Understanding the biology, the mechanics, the challenges and the realities of delivering a safe and effective medicine, makes us intelligent consumers and creates a realistic expectation for what's to come. Armed with this knowledge we can better appreciate the significant work being done by the Biopharma industry and regulatory authorities to get a vaccine to the global population. We hope you enjoyed all four installments of our vaccine series.
We encourage you to visit us at criver.com/vitalscience to listen to any episode you may have missed. And as always we welcome your feedback at firstname.lastname@example.org
until next time. (soft music)