Brief History of mRNA Vaccines
The first published human trial of an mRNA vaccines was of a rabies vaccine. CureVac a Dutch Company specializing in mRNA vaccines and scientists at the University of Tübingen developed this vaccine. The human trials followed many pre-clinical studies in lab animals. The scientists were trying to develop a vaccine platform which will enable cheap and rapid vaccine development. The mRNA vaccine field was developed to address novel viral pandemic like what we are currently experiencing.
About 101 young volunteers ages 18 – 40 years received the rabies mRNA vaccine CV7201 between October 2013 – January 2016. The investigators used already available tests for the current available rabies vaccine and declared CV7201 effective. Thus according to the medical literature the first reported use of mRNA vaccines in humans was about 7 years ago.
On a recent online poll that I published here about a week ago many who were unsure or do not want to take the Covid-19 mRNA vaccine said that they thought the vaccine was developed too quickly. This post is my effort to address this misconception. The rabies study was the result of many years of effort including several in mice, pigs and other lab animals. At any rate the publication followed more than 2 decades of preclinical research many probably never making it to the medical literature. Saying this vaccine was developed too quickly is similar to a renter refusing to live in a home built with prefabricated building materials because it only took a week to construct. Such buildings are developed quickly because the constituent parts were already developed and tested in prior buildings.
Were The Earlier Vaccines Safe?
The earlier mRNA vaccines were generally safe according to the reviews of the literature. In the first published study, of an mRNA vaccine one participant was diagnosed with Bell’s Palsy. Reports of Bell’s Palsy in people getting the Pfizer and Moderna vaccines is therefore not surprising. In both instances these events were mostly transient. One other person had a treatable thyroid disease (auto-immune thyroiditis). Researchers considered that outcome to be not related to the vaccine. The investigators determined that the rate at which this condition occurred was similar to what is observed in unvaccinated populations.
Reported Side-Effects in Phase 1 Studies of mRNA Vaccines
Many have expressed theoretical concerns of higher degrees of immune system activation due to stimulatory sequences within mRNA vaccines. This has the potential to cause increased rates of auto-immune disease. At this time though the common associated side effects seen in these studies have mostly been fevers, headaches, pain and redness at injection sites, fatigue, muscle aches and a few cases of joint pain. The prior studies of mRNA vaccines did not report any severe allergic reactions. This is probably because these studies excluded individuals with high risk for allergies.
Can These Vaccines Really Change Our Genetic Code?
Knowledge of nucleic acid vaccine technology which includes both DNA and RNA vaccines is not new. Before the first reported use in humans in 2013 there was more than 2 decades of work. The technology currently allows easy and rapid vaccine development and manufacture. However early candidates vaccines showed limited immunogenicity (ability to effectively stimulate the human immune response). The Pfizer and Moderna vaccines are thus the result of 3 decades of research. Most researchers favored RNA over DNA in the development process because there were some concerns of viral DNA getting into the human genome. This concern was however considered at that time to be very unlikely. RNA vaccines do not pose any risk of getting into the human genome for a few reasons.
- The mRNA does not go into the nucleus at all.
- Cells have many enzymes that break down these mRNA in the cell
- The enzymes required for such a RNA code to get into the genetic code are not available in regular cells.
- After 3 decades of research including several studies in lab animals no such integration of genetic code has been reported.
Schema Showing How mRNA Vaccines Stimulate Our Immune System
The mRNA never gets into the cell nucleus where the the genetic code responsible for our own proteins resides. The ability of RNA vaccines to produce the desired viral proteins in the cell’s outer cytoplasm is what makes them better than DNA vaccines.
How Must We Handle These New Vaccines?
Many in the scientific community consider the successful implementation of mRNA vaccines a major breakthrough. This is proof that a vaccine based on a viral mRNA sequence can be developed and implemented in the course of a pandemic. As we go through implementation of this vaccine we should all be aware that this is not the end but a new beginning. It is a new beginning because as many researchers in the field of emerging infectious disease continue to say “there will be other new emerging viruses causing new epidemics and pandemics“.
We must all be aware that we are at a crossroads in vaccine technology. I can understand the anxieties of those who want more time to consider whether to take the vaccine. It is easy to conclude the vaccine was developed too quickly if you only consider the time it took to develop this specific mRNA vaccine. I only suggest we consider this as a prefab vaccine!!
The technology platform central to the development of this vaccine was not rushed. The mRNA vaccine platform was developed to achieve just that purpose. Quick and rapid vaccine deployment from identification of virus to vaccine. From January 11th when the team at Moderna got the SARS-CoV-2 sequence to December 19th when it received a EUA was exactly 49 weeks. For the sake of humanity, we would need to be able to replicate this miracle in future epidemics and pandemics. I would be focussing on this miracle which took more than 3 decades to bring into being. These vaccines were not developed too quickly, if it had been quick Ebola would have been stopped in its tracks.
From what I have seen in the medical literature mRNA vaccines are generally safe. After more than 3 decades of development, no cases of RNA/DNA integration into the human genetic code has been reported. The 3 decades of work done was mainly to achieve one primary purpose, make it possible to develop a vaccine as quickly as possible. Yes, this time it took less than a year. It is my hope we can even make this timeline shorter.
By Dr. Leonard Sowah a physician in Baltimore, Maryland
Feature photo: The Covid Task Force Visiting the NIH Lab where the early work of the Moderna Vaccine was done.
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