COVID-19 Vaccines: What Does the Future Hold? – MedPage Today

Listen and subscribe on Apple, Stitcher, Spotify, and Google. And if you like what you hear, a five-star rating goes a long way in helping us "Track the Vax!"

We did it all. We social distanced, masked, got vaccinated, masked some more, and got boosted. But still, with Omicron -- a much more contagious variant spreading like wildfire -- infections are at an all-time high.

There remain more than 100 different vaccines in human trials and development for COVID-19, from protein subunits to inactivated coronavirus vaccines, as well as another 70-plus in animal trials.

So, is boosting with our existing authorized vaccines going to be our "new normal?" Or, are there new vaccines still in development that would allow us to truly be "one and done."

On this week's episode, Dial Hewlett Jr., MD, the medical director for Westchester County, New York, and deputy to the commissioner for the Westchester County Department of Health, joins us to explain what future vaccines are coming down the pike and where research will lead us.

The following is an abridged transcript of his interview with "Track the Vax" host, Serena Marshall:

Marshall: Despite vaccines, despite the strides we've made with them, we are still looking at a really bleak winter here. Is that because it's not that the vaccines aren't working, it's that the virus is sort of evolving?

Hewlett: That's fair to say. I think this new Omicron variant, unfortunately, seems to be much more transmissible than some of the earlier variants, including the Delta variant. And as a result of that, we have a larger number of people who are becoming infected. Certainly it has run rampant among those who are unvaccinated. But it has now led to a lot more of what we call breakthrough infections among people who are fully vaccinated.

Fortunately, those individuals who are fully vaccinated are experiencing only mild symptoms, similar to say, a common cold. So, I think that that's the good news, in that the vaccines are preventing serious illness and hospitalizations and deaths.

Marshall: But they're not bulletproof, and boosters are going to be what's necessary in order to really up that antibody protection?

Hewlett: That is correct. I think that we have understood now clearly the benefit of the boosters and we are encouraging everyone who is fully vaccinated, if they are eligible, to come into either their health departments or to their physicians' offices, or other places where they can get the boosters, because we believe the boosters are going to be very, very helpful in preventing further infections.

Marshall: But how often will boosting or this reboost be necessary when it comes down to it? Especially with these mRNA vaccines, which is what is being used in the U.S. the most, and what's being recommended now, even over the adenovirus vector vaccine.

Hewlett: I don't think that we can really answer that question accurately at this time. This is really a moving target. We don't know whether this virus ultimately is going to behave like the influenza virus, which requires a shot every year, because there are variants that occur -- not really variants, but there are changes in that particular virus that necessitate revaccination every single year.

So, we don't know if that may be the case with this virus at all, just like the others. I think we have to wait and see what's happening as far as that's concerned. We don't have to wait and see with regard to the effectiveness of these vaccines at preventing serious disease, because we've seen that that's definitely occurring.

Marshall: So, we don't know how often we'll have to get boosted with these mRNA vaccines, but we're hearing some good news about future vaccines -- like Novavax.

Hewlett: Yes, we are. And I think that one of the good things about that vaccine is that it does use a different type of platform. It uses what we call a protein subunit platform, so it's a protein-based vaccine, which is very similar to the platforms that are used for some of the other types of vaccines. I think the influenza vaccine is on a similar platform.

One of the good news pieces of this is that the availability of this new vaccine is going to increase the supply. And so it's going to allow for some of the underserved parts of the world to be supplied with vaccine, which, according to studies that were recently published over the summer in the New England Journal, this vaccine is close to 90% effective in preventing serious illness and hospitalization. So, that's very good news.

It may well be that if this vaccine is tested further, that it may be something that will be added to the armamentarium here in the United States. We don't have approval for this vaccine yet here in the U.S. and we don't have a COVID vaccine as of now that's in this class of vaccines that's available to us.

Marshall: So, you said it's a subunit protein vaccine. Explain for us how that's different from the mRNA vaccines.

Hewlett: Yes. If I can, not being a basic scientist. The mRNA vaccines actually couple the material from the virus, that is, they actually take pieces of the spike protein, and it's coupled with the messenger RNA. And that is actually the platform by which the vaccine operates.

With protein subunits, they are actually using what they call nanoproteins, which are just small amounts of protein, and what they call an adjuvant. They are using essentially the entire protein subunit, as I understand it, from the spike protein of the coronavirus. And so, in that way, it's a bit different. At the end of the day, all of the vaccines, whether it's an mRNA vaccine or a protein subunit vaccine as this one is, or a viral vector vaccine, which is what the J&J vaccine is, or the AstraZeneca -- all of these vaccines will generate what we call an antibody response. So, antibodies will be generated, which will neutralize the virus and hopefully prevent the person from getting sick.

But the other part that we don't talk about that much is that they will all also generate what we call a memory response through what we call the T cells or some of the white cells in our body. And this is probably very, very important -- not probably -- but is very important in terms of the duration of the protection that a person has.

Marshall: Do we know, though, if the subunit protein vaccines create longer protection memory?

Hewlett: We don't, we really don't. We really are going to have to wait and see what happens to the individuals who were involved in these initial trials. The trials that were reported in the New England Journal back in July involved about 15,000 participants. And so in order to know exactly how long protection is going to last, you have to follow these individuals longitudinally. And you have to look at their antibody responses over time and you expect the antibody levels to go down, but you also want to look at the percentage of individuals who may develop symptoms that would then be attributable to the coronavirus infection. And that's really the only way that we'll know how long the protection is going to last.

Marshall: I mean, it sounds like the Novavax vaccine is using more of traditional vaccination approaches than the mRNA, which is relatively, for all intent and purpose, brand new.

Hewlett: Well, yes. The mRNA vaccines have been used previously, but certainly the mRNA technology is much newer than the protein subunit technology. The advantage of the mRNA technology was that it allowed scientists to develop and produce the vaccine much more rapidly than the traditional protein subunit vaccine.

Marshall: But the protein subunit -- we have to just, to be clear here -- don't infect you either. There's no way you can get COVID from the vaccine?

Hewlett: That's correct. And that's true with all of them. So, you're not being injected with the virus. You are receiving protein parts of or either the entire spike protein, if you will, of the virus. And that is what generates the immune response.

Marshall: There's another vaccine, Dr. Hewlett, that's just out of phase I. So it's really early. And it's being called an umbrella vaccine, protecting not just against COVID, but all SARS infections. It is coming out of Walter Reed's medical center, U.S. Army. And that one they're saying is using a spike ferritin nanoparticle COVID-19 vaccine. Can you explain for us what that is?

Hewlett: Unfortunately, I don't know a lot about this. I do know that the principle is one that has also been applied to the influenza vaccines. That is, if you can develop a vaccine that is going to offer universal protection against a whole array of coronaviruses, that of course is going to be much better in the long run than the vaccines that we have now that seem to have maybe a narrower range of protection.

And I think what they're talking about here is this umbrella, if you will, would allow for coverage of a broader range. And they can do this, if they can recognize a portion of the virus that is consistent across the entire range of coronaviruses and direct a response against that one particular portion of the virus, which might be in addition to, of course, the spike protein, which has been the focus up until now.

Marshall: I mean, that sounds like a really cool option, but for the flu, are we getting one that targets 24 or 20, however many different units ...?

Hewlett: I think that they have been working on that for many years. The flu virus has two major targets, the hemagglutinin and the neuraminidase, and those are targets for the currently used flu vaccines. And there's a lot of interest in trying to develop flu vaccines, influenza vaccines, which will be directed at some of the other proteins, which are more consistent, which don't seem to change from year to year.

Marshall: Okay, so, the goal then here would really be to prevent any other variants from being able to infect with this singular vaccine. That sounds pretty great.

Hewlett: Yes. If that can be accomplished. And I have confidence in our colleagues who are working in the laboratories. The technology is improving every single day. They are able to come up with novel ways of developing new vaccine products. And so I'm confident that they will come up with something very soon.

Marshall: How long do you think we're going to have to wait, though, for that to really come out of phase II, phase III and be distributed for something like that?

Hewlett: That's a good question. I think that if we look at our previous experience with the mRNA vaccines, where they were able to come up with a viable vaccine within a period of about a year, of course, that was based upon some of the previous work that was done. Who knows, maybe within another year or so there might be something that will be available. It's really pure conjecture on my part. But it's certainly possible.

Marshall: But a little hope/light at the end of the tunnel.

Hewlett: Yes, for sure.

Marshall: Now there's another type of vaccine that are being worked on, and those are non-injectable vaccines. So, can you tell us how those work? Those are inhalers. We've heard about this inhaler use for things like the flu in the past. And is that a legitimate option here for COVID?

Hewlett: Well, yes, they are. Again, not being a basic scientist it's difficult for me to go through all of the details, but I think that whether you are injecting a vaccine or if you are inhaling the vaccine, if you can basically expose the body's immune system to a high enough volume of the antigens, as we call it, then the body is going to generate a response. And it will generate a response not only by producing what we call antibodies, but it will also generate a response through the memory cells or the T-lymphocytes as we like to call them. And I think that these types of vaccines are not totally new. There are other types of vaccines that have been administered via the inhaled route, so this certainly is exciting.

Marshall: So, explain for us, though, how that would work. So, a vaccine, it gets into your arm, it goes into your immune system via the bloodstream. But when you inhale it, it goes into your lungs. So how has that response different?

Hewlett: It does, but it also is going to be absorbed through the small blood vessels that are present. And the same is true when you receive an intramuscular injection. And it then is going to cause a response as far as your immune system is concerned, so it really doesn't matter the route by which the vaccine enters the body.

The thing that is important is whether there's enough stimulation of the immune system. So, there are vaccines which are administered orally, that you take by mouth, and, so, it certainly is plausible. And it makes sense since this particular infection, we primarily acquire it through the respiratory route, it is logical that you could use a vaccine that was administered via the same route.

Marshall: But one wouldn't be necessarily better than the other?

Hewlett: No, it wouldn't be. However, I think that as time goes on they will have to look at the profile in terms of how effective the vaccines are when they're administered via this route. And also, the safety and the tolerability, there are many people who do not tolerate taking things via inhalation. Individuals who have respiratory disorders might not tolerate this route as well.

Marshall: I mean, this all sounds really promising, a promising future for COVID as we deal with this continued outbreak. And, in principle, it seems like it would be fantastic, but access is still going to be an issue. I mean, initially it was with the vaccines, now it's with tests, and we're learning about new types of tests, molecular analyses that can be used at home as well. Is that a way to really then kind of get ahead of this, as we continue to ramp up those vaccine technologies?

Hewlett: Well, yes. And I think that we have to look back on some of the errors that were made in the past. Many years ago there was, I think, a withdrawal of support for our response to things like pandemics and natural disasters. And this was recognized by many of the experts in the field.

And even during recent years, the public health infrastructure has been pretty much dismantled and we've had dismantling of some of the areas like our National Institutes of Health. There were draconian cuts to the Centers for Disease Control. And, unfortunately, as these cuts were starting to take effect, we were faced with the pandemic.

And so we were ill-prepared to deal with this pandemic. And I think now there has been an awakening and I think that now the support to some of these infrastructure areas is being renewed. And hopefully as we move forward, we will be in a better position. But things like home tests are certainly going to be very, very helpful in terms of improving access, and, of course, the technology for the tests. So, I think that these are certainly steps in the right direction that the administration is taking in terms of dealing with this testing issue.

Marshall: Is the problem or is the solution, I guess, going to be these new kinds of vaccines and figuring out how to boost and have that protection last? Or is it going to be that with a variant like Omicron, everyone will slowly get infected? And then it turns into more of a flu-like illness and we use testing to return to normal?

Hewlett: Well, that's a difficult question. I think that all of us are hoping that maybe -- and we have to keep in mind that coronaviruses have been around for a long, long time. They've been known as pathogens in animals since the 1930s. And they were identified as pathogens in humans in the late 1960s. And we know that the coronaviruses are responsible for about 30% of the common colds in certain parts of the world -- and so it is hopeful that as a result of many of the measures that are being taken, that it may return to that status.

Before we had SARS 1 and then MERS, the coronaviruses were felt to be rather benign. And so what happened to us in 2020 was totally unexpected, but possibly with a lot of the measures that have been taken already, combined with testing, we will be able to achieve normalization or at least a level of control.

But it may well be that in the future, we may have to include vaccinations for coronaviruses along with vaccinations for influenza, that's certainly a possibility on the horizon.

Marshall: And that's another vaccine that's being worked on, combining the two?

Hewlett: Yes. If you could combine them, that would really be a very good thing for people, so that when they got their flu vaccines every year, they could also get protection against coronaviruses.

Marshall: In the short term, though, just two arms, right? Roll up both sleeves.

Hewlett: That's pretty much where we are right now. We have to emphasize to everyone that the COVID-19 vaccines and boosters do not protect you against influenza. And the influenza vaccine does not protect you against COVID-19.

Marshall: Okay, well, I guess it sounds like COVID is here to stay for at least the long term and vaccines do remain our best weapon against them. But is the idea now that we reframe the goal to COVID testing and care?

Hewlett: Well, I guess we're going to have to ... there's no one solution. I think we can't get rid of testing just because we have vaccines. And just because we have testing, we can't stop vaccinating and encouraging everyone to be vaccinated and to have boosters. I think we have to have a multifaceted approach.

And I think while we're in this outbreak of the Omicron variant, we also have to emphasize the other things that we know are helpful in preventing infection, like masking and distancing, and also, unfortunately, avoiding large indoor gatherings, until this is under better control.

See the original post here:

COVID-19 Vaccines: What Does the Future Hold? - MedPage Today