Medical innovation

Q&A: What to know about COVID-19 vaccines

A DO clinical geneticist who works in new drug development discusses the trial data for two COVID-19 vaccines, how mRNA vaccine technology works, and more.

Editor’s note: This story was published before the FDA issued emergency use approval for the Moderna vaccine. Learn more.

During the darkest days yet of the COVID-19 pandemic, the recent emergency FDA approval of a vaccine created by Pfizer and BioNTech has made many hopeful that new cases will begin to decrease over the coming months.

With the Pfizer/BioNTech vaccine currently being distributed to health care workers across the U.S. and a similar product from Moderna under final review, The DO spoke to Andrea Amalfitano, DO, dean of Michigan State University College of Osteopathic Medicine and a clinical geneticist who works in new drug development, about what to know about these vaccines. Following is an edited Q&A.

How encouraged are you by the current COVID vaccine trial data from Pfizer/BioNTech and Moderna, two companies whose latest vaccine products are driven by mRNA technology?

The efficacy data suggests both vaccines are greater than 90% effective in preventing a natural COVID-19 infection that causes symptoms. Those are stellar numbers. There was a reasonable number of trial participants that were involved, making those numbers even more significant.

I’m also encouraged by the fact that the Pfizer product in particular, in phase I studies, looked at several different flavors of that product. All of them looked similar in those earlier stages, but the one they went forward with looked the safest. They had the fewest minor side effects. That encourages me as we begin to ascertain the safety data.

How does mRNA vaccine technology differ from what is used in typical vaccines like the flu shot?

These are unique formulations of a vaccine. These are RNA-based molecules, modified to be more stable, encapsulated in a liposome formulation to create what is almost like a protective shell. The RNA serves as a cookbook. Once injected into an individual, the individual’s immune cells will actually read that book, manufacture an element of the virus (the spike protein), and create an immune response to it.

That is unique. Traditional vaccines take the virus you want to vaccinate against, grow it in the laboratory, and then inactivate it chemically. When a traditional vaccine is given to a patient, their immune system sees the inactivated virus without the involvement of mRNA. In the end, you want an immune response to the virus itself. Both formulations will accomplish that, just in different manners.

RNA technologies have been around for a while. Many humans have received RNA-based therapeutics in the past, particularly in clinical trials. These vaccines will be the first drugs using mRNA that are approved for widespread use.

A disadvantage is that we still don’t know if they are scalable because they have never been given to a large population. These next few weeks/months we will see if the manufacturing process can be consistent when going from providing tens of thousands, or even millions, of doses to tens of millions or hundreds of millions. That is not a small feat.

What would you say to people who are concerned that this type of vaccine has never been deployed on a mass scale before?

Early data in studies show that these formulations appear to be very safe. The only side effects I saw in what is published so far look reasonable: soreness at the injection site and a transient, mild increase in temperature that can be treated with something like acetaminophen. This is typical for vaccines, so there is nothing standing out here.

Once you move into millions of individuals after testing in tens of thousands, there is a limitation to predictive capacity, so what we typically do is post-monitoring, even after getting approval. These are thought of as “phase IV” studies. Yes, the vaccines are approved for more widespread distribution and use, but there is still a continued monitoring for potential problems or side effects.

We also want to confirm if the original efficacy we saw in phase III studies (that led to approval) continues in phase IV. It is not like “once the stamp goes on, we’re done.” There will be a continued observation as more and more individuals receive this formulation. There are safeguards in place to monitor this as we go forward.

Health care professionals and their families are the first in line to get this vaccine, along with those in long-term care facilities. What should doctors expect when they get the vaccine and afterward?

Distribution does vary geographically to a degree. Individual states will ultimately control the distribution of the vaccine they get, the amount of that vaccine they get, and even potentially the type of vaccine they get. There are multiple vaccines in the pipeline, with different scalabilities and availabilities. One state may receive one vaccine while one may receive another. That may then guide downstream availability.

For example, the Pfizer vaccine requires storage at minus 70 Celsius, so one state may have a differential capacity to store that vaccine versus the Moderna product, which doesn’t require as rigid of refrigeration. The Moderna vaccine may be a little easier to distribute, especially to rural areas.

Overall, I’m leaning on the current CDC guidance. My advice is to go to the CDC website for updates, your local state medical society or department of health for guidance specific to the state, and then your local venue, maybe your county’s public health official, to see what their expectations are. See how physicians can not only be recipients of the vaccine, but also assist in the distribution as more vaccine becomes available. We’re going to be in the thick of this, both on the receiving end and on the delivery end.

It’s good we have additional vaccine candidates in the pipeline of testing. Those are ongoing. As they are approved, the manufacturing capacities of those vaccines can be brought to bear on this equation. As we get more partners involved, and more logistical capacity for scaling up, the more rapidly the greater population can get vaccinated.

At this time, it’s estimated that the vaccine will be available to the general public in late spring or early summer. Is there anything physicians should do to prepare, and do you have any recommendations for combatting vaccine hesitancy?

Much of what we do as physicians is translating scientific knowledge for patients in a manner that helps them make an informed decision they can be confident about. What we can do is look at the scientific evidence that comes out on these specific vaccines, and note that they exactly parallel similar historic vaccines we have used routinely for decades, including the flu vaccine, which is very safe and effective.

Given the daily impact of COVID-19, it is important do everything we can to minimize risk, especially to the most vulnerable in our population.

The final point I always raise with families is that next to sterile/clean water, vaccines have been the most impactful intervention to reduce disease and death in humans, period.

The COVID-19 vaccine is just building on decades and decades of the success we’ve had in developing vaccines. There is nothing out of the ordinary with this one. We can use that foundation of success and knowledge to help inform those who might be hesitant.

Related reading:

Long COVID may have an explanation: What physicians should know

Father-daughter DO team at Cleveland Clinic research COVID-19 inflammation and immunology

Leave a comment Please see our comment policy