Introduction: Vaccine technology has improved substantially since the first smallpox vaccine, developed more than 200 years ago. As technology improves, vaccines can be produced more safely and reliably for many different pathogens. A recent breakthrough saw the first full deployment of mRNA vaccines to fight a pandemic. Despite the technological and logistical feat of developing a viable vaccine in an abbreviated time frame, there have been many questions about this new approach to vaccine development. The current review will provide descriptions about different types of vaccines as well as answers to some common questions about mRNA vaccines. The purpose is to provide military medical professionals with the information needed to better convey the importance and function of these new vaccines to service members.
Materials and methods: There were no explicit inclusion or exclusion criteria for articles describing mRNA vaccine technology. References included here were intended to illustrate important principles or empirical evidence in demonstrating the safety, efficacy, and function of mRNA vaccines.
Discussion: The review describes three different types of vaccines: whole-pathogen, subunit, and nucleic acid. Each vaccine type has different implications for the development and production of a vaccine line. For example, whole-pathogen and subunit vaccines often require growing significant amounts of the vaccine sample in laboratory before the material can be incorporated into the vaccine. Nucleic acid vaccines instead provide cells the opportunity to produce key proteins without needing to reproduce the virus and attenuate it in a laboratory setting. This approach has a notable advantage of speed in moving from genome sequencing to vaccine production, but it also creates some potential confusion. The discussion covers three questions with regard to this confusion. First, was the vaccine developed too quickly? Speed here is a byproduct of the new technology and unprecedented government interdepartmental cooperation. No steps were skipped in development or production. Second, does the vaccine modify DNA? No, the mRNA vaccines never enter the cell nucleus and therefore cannot modify DNA. The discussion clarifies how mRNA enters cells and produces the key proteins required to stimulate an immune system response. Third, how long will immunity last? Because mRNA vaccines are new, long-term immunity cannot be projected without significant further study. Still, the discussion does cover issues in determining vaccine efficacy in clinical laboratory trials versus field effectiveness in the real world.
Conclusions and future uses: These mRNA vaccines are the newest and most sophisticated defensive tool military medicine has against emerging biological threats. Evolving dangers, such as synthetic biology and engineered pathogens, further enhance the importance of having defensive countermeasures that can be rapidly deployed in response. Current evidence suggests high safety and effectiveness for a biological countermeasure, decades in the making, and military medical personnel should feel confident using and recommending this technology to ensure force health protection.
Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2022. This work is written by (a) US Government employee(s) and is in the public domain in the US.