A Physician’s Open Letter to Fellow-Catholics on COVID-19 Vaccines and Treatments

Part I: A review the history and data on mRNA vaccines

"There is no pathophysiologic or historical reason to believe that a new, previously unseen side effect from either of the mRNA COVID-19 vaccines will suddenly occur months to years after it has been given" -- Dr. Gwyneth Spaeder
"There is no pathophysiologic or historical reason to believe that a new, previously unseen side effect from either of the mRNA COVID-19 vaccines will suddenly occur months to years after it has been given" -- Dr. Gwyneth Spaeder (photo: Insta-photos / Shutterstock)

The public debate over COVID vaccines, their efficacy and their morality has been seriously distorted by disinformation, often passed along the internet and social media by well-intended individuals. 

I should like to offer answers to some Frequently Asked Questions and present constructive criticism on the incomplete or incorrect assertions and conclusions I frequently hear. I write as a physician who has spent the last 20 months working with COVID patients and their families. I write specifically as a pediatrician who has watched children lose parents and grandparents, months of education, and sometimes their own health to this virus. 

I write also as a mother who has tried to balance my vocational call as wife and mother with my duty to my patients; to reconcile what I know to be scientifically valid with my desire to return my family life to normal, and to continue to work with my husband to raise our children in the Catholic faith, using the challenges of this historical moment to emphasize that Catholicism honors both faith and reason.


Did the 2020 Note from the Congregation for the Doctrine of the Faith on the morality of using some anti-COVID-19 vaccines rely on incomplete data? 

To date, the most authoritative Catholic statement on COVID vaccines is the 2020 Note from the Congregation for the Doctrine of the Faithconcerning the use of some COVID-19 vaccines. It is sometimes claimed that, at the time the Note was written, there was incomplete data on both the nature of the design and of the components used in the mRNA vaccines produced by Pfizer and Moderna. It is understandable that many people had questions regarding the use of mRNA technology when these vaccines were first granted Emergency Use Authorization by the Federal Drug Administration. 

It was not a lack of data, however, but a lack of familiarity with the involved science among the general public, that created these concerns. A brief biology review is in order here, as much of the initial concern I have heard from parents of patients, as well as from friends, was due to the mistaken fear that injecting mRNA into our muscles could somehow change our own unique genome. This simply cannot happen.

Messenger RNA, or mRNA, is a molecule that tells our body how to make proteins. Once the protein is made, the mRNA is degraded and passes out of the body with other waste products. This process only occurs in one direction. There is never a chance of modification of the vaccine recipient’s own genome as the process of transcription and translation by which proteins are made only moves forward: DNA to RNA to protein. It cannot work in reverse. (The exception to this involves reverse transcriptase enzymes, such as contained in HIV, a retro-virus, but are decidedly not present in the mRNA vaccines.)   

This process is entirely different from what is known as gene therapy, in which there is a targeted insertion of DNA directly into the nuclear genome in order to permanently change the genetic code for a therapeutic purpose. The mRNA vaccines are working “downstream” of DNA as I described above and therefore cannot alter the vaccine recipient’s genome. 

As for the components of the Pfizer and Moderna vaccines, they are known, published and freely available for review by anyone who wishes to investigate. In fact, these are some of the “cleanest” vaccines ever made, lacking many of the preservatives that have (incorrectly) concerned many people about other, older vaccines. 


Are these mRNA vaccines safe and effective? 

One of the first questions I often hear concerning these vaccines involves the speed at which they were developed. I understand why the timeline could be construed as suspect, given our common experience of rushed-function-leading-to-poor-outcome. I can confidently assure those who query me on this point that three important facts should allay their concerns. 

First, most medical research (especially pharmaceutical research) proceeds at a glacial pace because of paperwork and competition. The filling out, filing, submitting, reviewing, correcting, re-submitting and waiting-for-a-response-before-moving-onto-the-next-step that is a reality for every researcher was expedited in this instance due to the urgency of the situation. 

Moreover, a specific research team is (almost always) competing for time and attention (physical resources, funding and slots on review board schedules) with other teams investigating other medical issues. These factors in the typical development that lead to delay of approval were all cleared away when the decision was made to prioritize COVID-19 therapies and vaccines. This meant that the mRNA vaccines could be safely brought to the public in a shorter-than-usual time frame. The actual science was not short-cut: The studies on safety and efficacy for both Pfizer and Moderna were enormous studies with plenty of power to support their conclusions. 

Second, mRNA technology is not new. This technology has been studied and pursued as a possible therapeutic agent since the 1970s and several pharmaceutical companies have been working with it in cancer therapeutics since the late 1990s. What previously limited its successful application in vaccine medicine involves technicalities about the rapidity with which it degrades in the body. That characteristic should be reassuring to anyone concerned about long-term safety. It was only when discoveries were made in the 1990s about the use of certain lipid (fat) particles as delivery and stabilizing agents that mRNA vaccines became feasible. 

The Pfizer and Moderna COVID-19 vaccines use mRNA to “teach” our bodies how to make COVID-19 spike proteins. These are proteins that stick up from the surface of the viruses and help it to enter and infect cells. They’re also the part that our immune system reacts to. The mRNA vaccine contains the instructions for this very specific type of protein, and since it is only a small part of the virus, there is no risk of actual infection. 

The mRNA is degraded once it has delivered its instructions — it can’t replicate on its own because we don’t have the specific DNA to make more of it. The protein can’t replicate on its own once the mRNA is gone. And the protein will be gone, too, once the immune system learns to recognize it and eliminate it. 

Third, in the history of vaccine science, no side effects have been detected after the first eight weeks of use in the general population. When the polio vaccine was first developed in the 1950s, there were rare cases of paralysis that occurred within four weeks of someone having received the oral live polio vaccine (which is no longer used in the United States). 

The yellow fever vaccine has a few very rare side effects (brain stem swelling in young children, organ failure in older individuals) that can occur within one week of vaccination. The influenza vaccine is rarely associated with Guillain-Barre syndrome, which can develop within eight weeks of vaccination. That we are now approaching a year of global distribution of these COVID vaccines to billions of individuals with no newly emerging long-term negative effects should be reassuring. There has been a very small risk of myocarditis, or inflammation of the heart muscle, following administration of the both the Moderna and Pfizer COVID vaccines. However, that risk was identified within weeks of widespread distribution, occurs within days of receiving the vaccine, is mild and self-limited, and remains lower than the risk of myocarditis from an actual COVID-19 infection. 

There is no pathophysiologic or historical reason to believe that a new, previously unseen side effect from either of the mRNA COVID-19 vaccines will suddenly occur months to years after it has been given. 

The COVID19 pandemic has created a historical experience that many of us have never encountered before, namely living through an evolving medical crisis in real-time.  Recommendations that change over time and newly applied scientific discoveries are understandably challenging for many to accept.  Fortunately, a large part of physician training involves learning how to critically assess and interpret data so as to be able to best help the individual patient.  Trusting your chosen physician has never been so important.

Part Two examines the question of immunity from COVID-19 vaccines, the benefit-risk equation, other safety concerns and possible treatments for the novel coronavirus.