Finding a COVID-19 vaccine
Watch infectious disease specialist Patricia Winokur, MD, discuss the race to find a COVID-19 vaccine and how UI Health Care is helping to find one through clinical trials.
Which COVID-19 vaccine clinical trial is University of Iowa participating in?
We’re participating in a phase III clinical trial that's sponsored by Pfizer and BioNtech, a company from Germany. The trial is evaluating a messenger RNA vaccine for COVID-19.
“Messenger RNA” may seem scary if you don’t know what it is, but do not be afraid. It is simply a vaccine that we inject into your arm like many others. Your body then creates an important protein that will help your immune system learn how to protect you from COVID-19.
What are the different phases of vaccine development?
The phases are an interesting way to study vaccines and are done with all vaccines that we create, including the COVID-19 vaccine.
We start in what we call a preclinical phase. The preclinical phase is a time where we’re evaluating the vaccine in animals. We look at the safety in the animals and whether they develop an immune response. We then look at the immune response to see if the vaccine prevents infection in the animals.
After animal testing, we move into small numbers of humans for testing. Usually 25 to 50 people or so participate in this. We pay close attention to safety during this phase since this is the first time we have tested the vaccine in humans. During Phase 1, we often look at different doses to see which dose is well tolerated, but also creates an immune response.
In this phase, we usually study several hundred people. We perfect the dose of the vaccine to find which one is best. We continue to follow the safety very carefully and also follow antibody titers in the blood. We look at which dose was the best tolerated and most effective at generating an immune response before moving on.
In Phase III studies, which is where we are presently with the COVID-19 vaccine, we’re looking at thousands of people. The goal there is to really continue to establish safety and evaluate whether the vaccine is doing what we think it’s going to do. In this study, the key is proving that this vaccine prevents infection with COVID-19.
How does the COVID-19 vaccine get approved?
The FDA is going to approve vaccines based on whether they prevent people from getting COVID-19. The vaccine must prevent infection at least 50% of the time before the FDA will consider licensing it.
Is an approved COVID-19 vaccine guaranteed to be effective and safe?
In practicing medicine, it’s hard to give a black and white answer like this because there is always an exception to any rule. Based on our understanding of vaccines and what we have seen in some of the early phase studies, we’re going to have a vaccine that works and is safe.
What we can’t say is whether it will protect 50% of people, 70% of people, or 90% of people from getting infected. We also are not sure on how long the vaccine will last without follow-up. Those are the things we will be evaluating so that we can answer them once the vaccine is approved.
Will the COVID-19 vaccine be similar to the flu shot?
The flu shot is not 100% effective, but it can make your symptoms milder even if you do get the flu. The flu shot is a really good comparison because it often truncates the severity of disease and is something you need every year.
Our guess is that this vaccine may not have long term effects and you may have to get additional doses at some frequency. We don’t know whether this will be every two years or three years or another amount of time. Based on what we know about coronaviruses that have been around for a long time, we think we’ll probably have to have booster doses at some point.
How will the COVID-19 vaccine affect children, pregnant women, or people with chronic health conditions?
We’re still in the testing phase, so we cannot say for sure. In the study that University of Iowa Health Care is performing and almost all of the studies that are underway now, we are testing adults between 18 and 85. This means we’re including the elderly, which we know is a population that can have severe effects from COVID-19. What we’re going to need to do is turn around and study the vaccine in children and those other groups specifically.
We know pregnant women can have serious effects from COVID-19. They will be an important population to try and prevent from getting infected if we can. For people that have other diseases that compromise their immune system, we will be doing special trials looking at their responses to vaccines as well.
We expect to be testing the effects on people for around two years.
When is a COVID-19 vaccine expected to be approved?
When we are studying vaccines, we are looking at them in an extremely rigorous way. So for this study, we’re looking at 30,000 people around the world–the first 6,000 people every day for a week after they’ve had the injection. We’re asking them really rigorous standardized questions about their symptoms and changes to their health.
Some example questions we’re asking study participants:
- Do you have a fever?
- Do you have fatigue?
- Did you have to go to the emergency room?
- Did you have to start a new medicine for any reason?
While we’re collecting safety information over a two-year period, oftentimes we can go ahead and approve a vaccine after a certain period of time–usually about six months.
Then we keep following and documenting the data for two years, which is really the icing on the cake. That starts to address the questions on if there are any long-term unanticipated results. We continue to watch to see if there are any side effects that we weren’t expecting as a part of our whole vaccine delivery system in the United States. This is a very important practice to continue.
We will also continue studying and watching blood antibody titers and watching to see if the vaccine is preventing you from getting COVID-19. The titers will help us see how long those COVID-19 antibodies last.
Even if a vaccine is approved, this is kind of a long-haul situation where we're really going to be looking to learn more about the virus itself, including how long until immunity is lost in people who have had natural disease and for those who have gotten a vaccine.
Once a vaccine is marketed, we have systems in place through the CDC that look for adverse events that were unexpected. That's something that we're always submitting as physicians and public health workers so that they can coalesce that data from around the country.
If the vaccine approval process is faster, how will we know getting the vaccine is safe?
We are not compromising any of the safety of this vaccine evaluation and production. What we have done is we've created protocols that have very set ways that we're going to move between phases. This helps speed up the regulatory background.
The government has accepted some of the risk for the companies, allowing them to go through that expensive manufacturing process before they even know if their vaccine is going to be approved. This means that as soon as the FDA thinks the vaccine is acceptable, safe, and effective, it can get into the public more quickly. If this vaccine doesn’t work, those vials are going to get thrown in the garbage and never be used.
Why is it still important for people to get the vaccine even if it is not 100% effective?
This is the story of trying to reduce symptoms. Oftentimes vaccines that are not perfect will reduce your symptoms once you get an infection. That's true with flu vaccines, often if you didn't get that vaccine you might get much sicker and maybe even end up in the hospital.
Having partial immunity from a vaccine is a good way to think about it. The vaccine helps reduce your symptoms and oftentimes reduces the amount of virus you shed. So that reduces your risk of transmitting it to your family members, fellow students in school, and everyone else you come in contact with.
Are people who are immunocompromised good candidates for the COVID-19 vaccine clinical trial?
We are looking for those that are between the ages of 18 to 85. In this phase III trial, we are allowing people to enroll if they had very stable diseases that could be immune mediated in nature.
Unfortunately, we cannot accept participants that are on some of the really potent immunomodulators. There are drugs now that are really good at reducing your immune response so your disease is improved, but that would be an exclusion for this study. We are allowing people that are that have immune diseases, but just aren't on those medications.
Eventually we'll be expanding into studying those who have even some of the immune modulators. Others have done different clinical trials with other vaccines and some of those people still respond nicely to vaccines by developing the antibody response that we want. So just because you're on those medications doesn't necessarily mean that you won't get an immune response.
Who will get the COVID-19 vaccine first?
There's a lot of discussion of how best to deploy the vaccine. Early on we probably won't have enough doses for every person in the country, so who do you start with? That's been a debate that's going on in the background.
There are vaccine experts and committees that decide who gets first crack at it. They might choose the elderly because they have been so disproportionately affected. They could also choose those with high risk conditions, such as hypertension, diabetes, or obesity.
Essential workers are going to be prioritized, including health care workers, workers that are keeping the food sources going, and others. The priority will then eventually expand to include as many populations as possible.
Once we have a vaccine, will we need to social distance and keep up other precautions like handwashing and wearing face masks?
Continuing to practice the necessary precautions will be the most important thing we can do for a quite a while.
The best way to prevent contracting COVID-19 is to wear masks or face shields, practice handwashing, and remain physically distant from others.
Everyone is tired of these practices and they feel monotonous, but it is important to reduce the spread now as well as when a vaccine is available.
Is it still important to make sure you get your flu vaccine this year?
It’s going to be more important this year than ever to get a flu vaccine. There are a couple of reasons why:
- We do sometimes see patients that get co-infected, where they get the flu and COVID-19 at the same time. That could be devastating since COVID-19 is a severe condition and 45,000 people already die from influenza each year. If you mix those two together, it would be terrible.
- We know that even people who have recovered from COVID-19 often have some lung damage that's still present. Some of them feel like they have asthma-like symptoms. If you then add the flu on top of that damage, that could really trigger some bad responses.
This is why it's more important than ever and that's even not even thinking about how difficult it will be to figure out what you have if you haven’t received a vaccine for either virus.
Symptoms between COVID-19 and influenza overlap a lot. We do have drugs to treat influenza, like Tamiflu, but we’ll have to figure out who has what condition so that you get the right treatment. We’re already stressing our testing stations pretty aggressively, so when you add flu testing onto that, it will make things really difficult.
Just consider this another reminder than taking precautions could not be more important. We want to prevent the spread of both COVID-19 and the flu. Stay home when possible, wear face masks when out in public, use hand sanitizer often, and wash your hands for at least 20 seconds.
If we were lucky and people were really diligent with those measures, we may see less flu than we normally do and maybe we would have fewer people dying from influenza too.
What do we know about the possibility of being reinfected for COVID-19? How a vaccine might prevent reinfection?
It is possible to be reinfected with COVID-19. That is why we think that this vaccine might be more like the influenza vaccine. We know that the influenza vaccine typically doesn't last more than six months. The good news is flu really is seasonal, so most of the time you get your vaccine in October and you're protected through the season which ends in March typically.
Coronavirus isn't showing that seasonality and we have individuals that have gotten re-infected in four and a half months. This suggests that this may not be a vaccine that lasts forever.
The data did show that the re-infection symptoms were very benign. This means that getting the vaccine, even though it may not be perfect and long-lived, may reduce the symptoms in a way that is similar to what we saw in those people that were reinfected.