The Lowdown on mRNA Vaccine Safety and COVID-19

I have noticed some patients and friends expressing fears over the new technology being used to create an mRNA vaccine to address the COVID-19 pandemic.  It seems that the vaccine development process is happening so quickly, and the use of genetics can cause people some worry.  Currently, mRNA COVID-19 vaccines are being developed by the companies Moderna and BioNTech-Pfizer. My goal is to break down the mechanism of these vaccines in an easily understandable way so that you can be well educated on their safety.

mRNA vaccines interface with your Ribosomes to make them generate small pieces of viral proteins in order to teach your immune system what to watch out for

Can this vaccine permanently alter my DNA?

Think of your DNA as your own personal encyclopedia of instructions. It is housed safely within the nucleus of your cells.  When your cells needs to produce proteins, mRNA is made by reading small sequences of your DNA in order to carry specific recipes outside of the nucleus.  The mRNA then travels to your ribosomes which are found both in the cytoplasm and endoplasmic reticulum outside of the nucleus. Once there, the mRNA recipe provides the information the ribosomes need to start making proteins. Once this process is finished, your cells degrade the mRNA using specialized enzymes. The mRNA vaccines work by introducing an mRNA recipe into your body that contains the instructions for making only a very tiny part of SARS-CoV-2 - a spike protein that occurs on the outside of the virus. This mRNA is kept safe by a lipid envelope, a protective layer that is found naturally in all of your cellular membranes.  Once introduced into the body, the mRNA makes it into your muscle cells near the injection site where it then interfaces with your ribosomes to start making the viral spike proteins. Your cells then take the spike proteins and displays them on the surface of the cell membrane in order to show them off to your immune system. This helps the body to create an immune response that protects you from future infection.  After the spike proteins have been made, the mRNA from the vaccine is degraded by your cellular enzymes. The mRNA never once enters the cell nucleus, and therefore it never once affects your DNA!  Furthermore, as this type of vaccine approach only uses your cellular function to produce a tiny innocuous piece of a functioning virus, there is no potential for the spike protein to affect your body adversely.

How did this vaccine development happen so quickly?

Ribosomes are found outside of the cell nucleus, which the vaccine mRNA never enters

Historically, many approved vaccines have taken an average of 10-15 years to develop, though it appears these mRNA vaccines are moving through the process at an accelerated rate.  It is important to understand that mRNA vaccine research has been being conducted for over a decade. Furthermore, we have a wealth of knowledge about other coronaviruses available.  Most vaccines we have developed have been made using a complete virus - either alive or dead. Once a vaccine like this has been developed, the manufacturing process can take quite some time to create enough viruses to be introduced via vaccine.  The mRNA model offers a much more streamlined manufacturing process.  Current genetic technology is lightyears ahead of where it was just 10 years ago.  Only five days after SARS-CoV-2 was identified, its entire genome was sequenced.  Moderna had a new vaccine candidate only 8 days after that.  Phase I trials were able to begin within 63 days. Since all that needs to be made is mRNA, rather than whole viruses, production can be rapidly scaled up through an enzymatic process. These vaccines are still subject to the same safety trial testing as any other vaccine.

What about other ingredients in the vaccine?

Because mRNA can be manufactured so rapidly, there is little risk for contamination as might be found in conventional vaccine manufacturing. Furthermore, the vaccines are kept at extremely low temperatures to prevent degradation of the mRNA, with the added benefit that this makes it difficult for contaminants to multiply if they do make it inside the vaccine contents. Because of this, there are no preservatives needed to be added to the COVID-19 mRNA vaccines. The use of adjuvants is sometimes of concern to patients. Adjuvants are materials added in order to provoke a greater immune response to a vaccine, which is typically used in vaccines made using complete viruses. The mRNA vaccines do not require an immune response to their direct contents, making adjuvants unnecessary. Remember that the vaccine works by merely giving your cells a recipe.