Two Vaccines in One Week Set Foundation for mRNA Platform Technology

On Friday, December 18, as widely anticipated, the FDA announced an emergency use authorization (EUA) for the sensibly named Moderna vaccine mRNA-1273, almost exactly one week following the EUA for the Pfizer-BioNTech vaccine BNT162b2. Both are lipid nanoparticle complexed, PEG shielded, sequence optimized mRNA immune stimulants designed to code for protective versions of the SARS-CoV-2 spike protein. As our cells take up the nanoparticles and use the mRNA code to produce the viral protein in situ, the molecular design of the vaccine will act to stimulate a productive immune response driven primarily by lymphocytes (a type of white blood cell). Such helpful immune responses have been shown to reduce serious COVID-19 outcomes by nearly tenfold in a total of 65,000 clinical trial participants across multiple countries and demographics.

These novel mRNA vaccines represent not just a blitz victory for immunology, microbiology, vaccine technology, and science in general, but they also set the foundation of a modified mRNA platform technology which may be able to protect us during future outbreaks. This accomplishment of science and scientists during a time of widespread skepticism signals a lasting triumph for nanomedicine as adroitly covered in this recent editorial in the December edition of Nature Nanotechnology. The variations between the two vaccines are minimal and mainly reflect the doses and different lipid nanoparticles used in their formulations. I would personally take whichever one is readily available, not just considering the initial first dose but also the follow-up second dose (four weeks apart for Moderna versus three weeks apart for Pfizer) which must be taken for optimal effectiveness. However, the most vulnerable and exposed members of our community should be prioritized.

Competition drives evolution and hence has shaped life on this planet. We would not exist without healthy competition. Likewise, having multiple similar vaccines approved within a week is a welcome development leading to better choice and the derisking of delivery disruptions. Much has been made of potential side effects, including swelling, redness, pain, and fever. The ancients knew these as tumor, rubor, dolor, and calor: the hallmarks of inflammation, or a productive immune response. Yes, in a sense, these temporary telltale signs show us that the vaccine is working, although each recipient will react differently due to the wonderfully resilient diversity of our species. It is always possible that a very small number of people may have severe allergic reactions as it can occur with bee stings, peanuts, or milk. Individuals with a history of anaphylaxis should seek medical advice before taking any vaccine. Our task is now to put aside fear and distrust and look to put our collectively vaccinated immune systems to work in checking the spread of this insidious coronavirus that has already killed over a million people worldwide. Stay cozy this winter, and may the lymphocytes be with you.

Dr. Sumen is the chief technology officer at Stemson Therapeutics and a member of the ASGCT Communications Committee.