As vaccination availability continues to expand, the long-term effects of the COVID-19 vaccines is one of the main hesitations. At the rate that the vaccine was created, this negative reaction is reasonable. How is it possible to know the potential long-term consequences of a vaccine that was just created? Let’s break down what is known.
While the mRNA vaccine is “new,” the technology is not. These vaccines have been used extensively in trials for years – in conditions like HIV [1] and cancer [2]. Actually, there is a clinical trial in phase II that is using mRNA cancer vaccine to treat cases of advanced melanoma [3] (if you want to know more about the different phases of vaccine development, you can read our post or watch our video about this topic). Pfizer and Moderna just took this technology and applied it to COVID-19.
In vaccines that use a protein* from the virus itself, like Novavax, or contain the protein in a harmless viral vector** (a tool to deliver genetic material into the cell), like J&J, the principle is the same. The protein is only introduced at the time of each dose, and is degraded by the body after a short time. Only the immune cells that have recognized the protein now remain in the body, ready to attack the virus if it ever enters the body.
Besides the mRNA, people have expressed concerns about the other ingredients [4]. Here’s a list of the ingredients for the three most common vaccines:
Pfizer Vaccine: mRNA, lipids ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate), 2 [(polyethylene glycol)-2000]-N,N-ditetradecylacetamide, 1,2-Distearoyl-sn-glycero-3- phosphocholine, and cholesterol), potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate, and sucrose. [5]
Moderna Vaccine: messenger ribonucleic acid (mRNA), lipids (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG], cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]), tromethamine, tromethamine hydrochloride, acetic acid, sodium acetate trihydrate, and sucrose. [6]
Johnson & Johnson Vaccine: Recombinant, replication-incompetent adenovirus type 26 expressing the SARS-CoV-2 spike protein, citric acid monohydrate, trisodium citrate dihydrate, ethanol, 2 hydroxypropyl-β-cyclodextrin (HBCD), polysorbate-80, sodium chloride. [7]
None of these vaccines contain eggs, preservatives, or latex. The other ingredients, (some with long, complicated sounding names) are the chemical names for common things like lipids, which help with vaccine delivery to cells [4]. Other names include salts, sugars, and acids that help stabilize the vaccine before it is administered [4]. All of these ingredients are in minute quantities, and are not dangerous to the human body. These ingredients, like the mRNA or viral vector containing the protein, are also broken down by the body. In the long-term, only your newly trained immune cells remain.
In most cases, the reason scientists and medical experts are not overly concerned about the long-term side effects is because there are no ingredients to cause long-term effects. This can be confirmed because the ingredients have been studied extensively, and have been used in many vaccines previously [8]. However, please discuss with your doctor beforehand if you have any known allergies or concerns about vaccination.
The important takeaway is that there are no ingredients in the vaccine associated with long-term effects. The components degrade rapidly and do not remain in the body. However, it is normal to be wary of the potential effects for something that seems unfamiliar. When breaking down this novel vaccine, it is clear that each part has been well-researched and understood for years.
*Protein - a molecule that forms the structure and gives function to organisms at the most basic level. Proteins consist of amino acids, which can be combined in different sequences to form different protein structures with different functions in cells.
**Viral Vector - a modified viral structure that is used to deliver a molecule of interest to desired cells. The infecting and dangerous features of the virus are suppressed and it acts as a vehicle carrying a molecule that will have some specific effect in a target cell. Some vaccines and gene therapies use viral vectors.
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Written by: Dominique
Edited by: María and Natasha
BioDecoded is a volunteer group committed to sharing accurate scientific information. If you have any questions about this topic, please comment or send them to our email.
References:
Moyo, N. et al. Efficient Induction of T Cells against Conserved HIV-1 Regions by Mosaic Vaccines Delivered as Self-Amplifying mRNA. Molecular Therapy – Methods & Clinical Development 12, 32-46 (2019). https://pubmed.ncbi.nlm.nih.gov/30547051/
Weide, B. et al. Results of the First Phase I/II Clinical Vaccination Trial With Direct Injection of mRNA. Journal of Immunotherapy 31, 180-188 (2008). https://pubmed.ncbi.nlm.nih.gov/18481387/
First patient dosed in BioNTech Phase II trial of mRNA cancer vaccine. Clinicaltrialsarena.com (2021). Available at: https://www.clinicaltrialsarena.com/news/first-patient-dosed-in-biontech-phase-ii-trial-of-mrna-cancer-vaccine/ (Accessed: 7th July 2021).
A Simple Breakdown of the Ingredients in the COVID Vaccines – COVID-19, Health Topics – Hackensack Meridian Health. Hackensack Meridian Health (2021). Available at: https://www.hackensackmeridianhealth.org/HealthU/2021/01/11/a-simple-breakdown-of-the-ingredients-in-the-covid-vaccines/ (Accessed: 7th July 2021)
U.S. Food and Drug Administration (2021). Available at: https://www.fda.gov/media/144414/download#page=2 (Accessed: 7th July 2021)
U.S. Food and Drug Administration (2021). Available at: https://www.fda.gov/media/144638/download#page=2 (Accessed: 7th July 2021)
U.S. Food and Drug Administration (2021). Available at: https://www.fda.gov/media/146305/download#page=2 (Accessed: 7th July 2021)
Different COVID-19 Vaccines. Centers for Disease Control and Prevention (2021). Available at: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines.html (Accessed: 7th July 2021)
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