If you have watched the news during the past year, you’ve likely heard about mRNA vaccines. You may even have had a more personal connection to mRNA vaccines. If you received either the Pfizer or Moderna COVID-19 vaccines, you received an mRNA vaccine! Perhaps you heard that GW served as a clinical trial site for the Moderna mRNA vaccine, and may have volunteered for the clinical trial.
How do these vaccines work? Traditional vaccines trigger immune responses in the body through injecting “a weakened or inactivated germ into our bodies” (CDC, 2021). mRNA vaccines work differently. Messenger RNA, or mRNA, is a type of ribonucleic acid (RNA) that uses information in cells to create a blueprint for protein production within the body (NLM, NIH, HHS, 2021). mRNA vaccines introduce “a piece of mRNA that corresponds to a viral protein, usually a piece of a protein found on the virus’s outer membrane” (NLM, NIH, HHS, 2021). Your body uses this mRNA as a recipe, and cells start to make this viral protein. “As part of a normal immune response, the immune system recognizes that the protein is foreign and produces specialized proteins called antibodies” (NLM, NIH, HHS, 2021). These antibodies protect against infection “by recognizing individual viruses or pathogens, attaching to them, and marking the pathogens for destruction” (NLM, NIH, HHS, 2021).
The surface of the COVID-19 virus (Coronavirus SARS-CoV-2) is covered in “spike proteins,” a glycoprotein that helps the virus enter a host cell by binding to a receptor on the surface of a host cell and fusing the viral and host cell membranes together. mRNA COVID-19 vaccines teach the body how to make this spike protein, (CDC, 2021). Once vaccinated, your body begins to recognize this spike protein as an intruder and begins to produce antibodies to fight off these spike proteins. Once you have these antibodies, they will be able to identify these spike proteins should you be exposed to the COVID-19 virus (Coronavirus SARS-CoV-2). If you do have a Coronavirus SARS-CoV-2 exposure, these antibodies will quickly identify the spike proteins surrounding the virus, attach themselves to these spike proteins, and destroy the COVID-19 virus before it is able to cause serious illness (NLM, NIH, HHS, 2021).
The following video produced by the Mayo Clinic provides a straightforward overview of how mRNA vaccines work against COVID-19:
Many people believe that mRNA vaccines can alter their DNA. However, this is not possible through mRNA vaccines. Once the mRNA has delivered the instructions of how to make the protein to your cells, the mRNA is broken down fairly quickly and “it never enters the nucleus of your cells, where your DNA is kept” (Mayo Clinic Staff, 2021). Since the mRNA never interacts with your DNA, your DNA will not be altered in any way from an mRNA vaccine.
While mRNA vaccines may seem new, they have actually been researched for decades. The first report of a successful mRNA vaccine was reported in 1990 in animals (Pardi et al., 2018). mRNA vaccines have distinct benefits over traditional vaccines. Among these benefits are safety and production. Because the vaccine does not contain the virus itself, there is no risk for infection. Production of mRNA vaccines have the “potential for rapid inexpensive and scalable manufacturing”(Pardi et al., 2018), as has been demonstrated during the COVID-19 pandemic. For a more in-depth scientific review of pre-COVID-19 mRNA vaccines, Pardi, Hogan, Porter, and Weissman’s review article titled mRNA Vaccines - A New Era in Vaccinology provides an excellent overview of mRNA vaccines.
References:
Centers for Disease Control. (2021). Understanding mRNA COVID-19 Vaccines. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/mRNA.html?s_cid=11344:mrna%20vaccine%20technology:sem.ga:p:RG:GM:gen:PTN:FY21
Mayo Clinic Staff. (July 31, 2021). Different types of COVID-19 vaccines: How they work. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/different-types-of-covid-19-vaccines/art-20506465
Mayo Clinic. (2021, February 8). Mayo Clinic Insights: How mRNA Vaccines Work . Mayo Clinic YouTube Channel. https://youtu.be/RvR_yf_haqQ
Pardi, N., Hogan, M. J., Porter, F. W., & Weissman, D. (2018). mRNA vaccines-a new era in vaccinology. Nature Reviews. Drug Discovery, 17(4), 261–279. https://doi.org/10.1038/nrd.2017.243
U.S. National Library of Medicine, National Institutes of Health, Department of Health & Human Services. (2021). What are mRNA vaccines and how do they work? https://medlineplus.gov/genetics/understanding/therapy/mrnavaccines/
