mRNA vaccines were always a promise of the future. They would be easy to produce and can be made rather quickly. Not that long ago, the promise of an RNA vaccine coming into fruition was still a few years away, progress wasn’t slow but there was no urgency, we would take our time to study this innovative concept and roll it out eventually. We would study this concept out of science fiction and explore every avenue of its benefits and potential issues before going into humans. All that has changed with COVID-19 being introduced to the world which as we all know has resulted in a pandemic. Suddenly no stone was left unturned, in the vaccine space all techniques to shorten this burden on our lives were at play, including convalescent sera therapy (simply put, taking the plasma from a person who has had COVID-19 and has developed antibodies against it and putting it into someone who’s at high risk for it but hasn’t contracted the virus yet) which from an innovation stand was not that progressive, but it works. Pfizer and Moderna have both within days of each other have announced that their clinical trials of their respective mRNA vaccines produced safe responses in their participants. As the world waits to breathe a collective sigh of relief, the infection numbers surge out of control for a second time in the Western world with pockets of resurgence in the East. As we wait for FDA approval for these two miracle drugs, I wondered how did a concept that was moving at turtle pace suddenly beat the hare at the finish line?
To answer this you must understand how mRNA vaccines work. A traditional vaccine (one that most of you are afraid to take, including medical professionals (shame on them)) like the flu vaccine or shingles vaccines is designed to introduce to you a piece of the offending disease whether it is an inactivated virus or an antigen (a protein or fragment that resembles part of the virus). The idea is to get your body to elicit an immune response to the vaccine such that your body will create a memorable defensive response should you be exposed to the disease post-vaccine. Different vaccines have different durations of its ability to retain that memory in the body.
mRNA vaccines work by introducing mRNA (which is nothing more than a photocopy of the offending virus’s RNA (they don’t have DNA like humans, they work with RNA) into cells in the human body. When foreign mRNA is introduced to the body thanks to the vaccine, your body’s immune defenses wake up, while the mRNA is translated in the cell it produces an antigen (similar to the ones contained in traditional vaccines). In effect it’s using your body’s cells (a small amount) to turn them into factories to make the vaccine within you.
The safest part of all this is that your DNA is never touched. Because we are introducing a photocopy of the virus RNA into your cells it never touches your DNA, it already has all the instructions to tell the cells in your body to make the antigen without touching your natural DNA. The bad part? It’s not easy to store, that’s the part of the story where the progress of mRNA vaccines comes in, we have not gotten so far in the development of such vaccines to the point we thought about making it easy to get into humans (since until COVID-19 we were no where close to having one for clinical trials in humans and no approved mRNA vaccines exist at this point) and we never expected to deploy it at such an accelerated pace or require such high quantities at once. The Pfizer vaccine requires you to take two doses three weeks apart, not to mention it needs to be stored at -70C in -80C freezers (something your local CVS doesn’t necessarily have and found typically in labs). The Moderna vaccine also needs to be administered over two doses, four weeks apart, but can be stored at -20C, which gives it a slight advantage as these freezers are more typically around making it easier for circulation in areas where specialized freezers are hard to come by.
So how did a vaccine concept go from baby steps to being the contender for the first line of COVID-19 vaccines that will reach the American public in 8 months (closest record before this was four year)? It’s easy to make, all you need is a map of the virus’s RNA (the viral genome of the disease in question) and you can put together the basic subunits of your mRNA vaccine with ease. It is what probably motivated Pfizer and Moderna in the first place, it was a risk worth taking. With data from both their clinical trails showing positive news, it is expected that they will wrap up with FDA regulators within weeks to deploy this to the American public.
The novelty of the technology (which was nowhere close to being a real player anytime soon) juxtaposed against the need for a stopping block against the pandemic no doubt weighs on the conscience of the FDA and the CDC in their decision making process on the safety and the potential of the vaccine to prevent COVID-19 over time (efficacy). Necessity is the mother of all invention, and two pharma companies have delivered the calling. While we wait for other vaccines to deploy (and they will soon enough) we have no choice but to take a leap of faith with the confidence of safety from their clinical trails combined with their expertise of delivering safe drugs and products to their customers in the past. As the COVID-19 crisis goes into it’s second act, mRNA vaccines are poised to leapfrog into their first, hopefully transforming the way we prevent diseases.