By Mohamed A. Hendaus-Rahal, MD, FAAP

As with the introduction of any novice agent, the Covid-19 vaccine is causing fear and concern about its safety and efficacy in certain populations. This fear could be attributed to the inadequate public knowledge of this vaccine. The currently introduced Covid-19 vaccines are based on messenger ribonucleic acids (mRNA). Below, you will be able to find answers to the most common asked questions regarding Covid-19 vaccine.

What is an mRNA vaccine and how is it different than traditional vaccines?

The majority of the conventional vaccines use either live or attenuated (weakened)  pathogens to boost the body’s immune response. Live “bugs” are usually found in the oral polio vaccine and the in subcutaneous vaccines such as measles , mumps, rubella ( MMR) and varicella .These

conventional  vaccines take long time ( years to decades) to manufacture, test, and get approved. In addition, they are expensive to produce .
Our white blood cells , which are considered  as our defense soldiers, sense the pathogen and frame a defense against it by generating specific antibodies to combat it. 

Covid-19 vaccine targets the S protein (Figure 1) via messenger ribonucleic acids (mRNA), the molecule that instructs cells what to build.  Once the S protein is produced within the body, it is considered as an antigen and the body commences the production of antibodies to fight the real disease, if contracted .

This type of vaccine was chosen mainly because it be can manufactured quickly , without bypassing the safety phase. Furthermore, its production is laboratory based, and the process is standardized.
The fastest way to make a vaccine in the midst of a pandemic is allowing the body to mount the production of antibodies against a protein on the surface of a virus ( S-protein in the case of Covid-19). RNA is a common molecule in our bodies and all living things use thousands of  RNAs as messages to encode within the cells. mRNAs in our bodies are meant to be transient or function for a short period of time ( minutes to hours) . An analogy to mRNAs is “post-it note” .  

Once the post-it note is used, it will be shredded or discarded. The mRNA vaccine operates the same way.

Once the mRNA portion of the vaccine is injected into the body (Figure 2), it travels to the cell through lipid ( fat) nano( very small ) particles. Once it is in the cytoplasmic part of the cell, the lipid carrier is degraded exposing the mRNA leading to instructing the immune system. The specific instruction is to create an immune response to the S protein, by recognizing that the protein does not belong there and begin building an immune response . In the cytoplasm, the cascade of protein synthesis is triggered in the cellular organelles known as the ribosomes. Once the message is read, the mRNA eventually disintegrate. Therefore, mRNA are like “snap-chats” in Instagram .  

What studies were done to show that these new vaccines are safe?

The mRNA vaccine has successfully passed all the phases of vaccine testing process without any shortcuts.
How do we know that these new vaccines are effective?
Thousands of volunteers have received the vaccine during the vaccine testing process and the effectiveness of the Pfizer and Moderna vaccines ranges from 90% to 95%.

The data was not only monitored by the companies that manufactured the vaccines, but also by international and independents  data & safety monitoring boards.

Is there a possibility that these vaccines could change our DNA?

mRNA functions in the cytoplasm of the cell and does not interact with the nucleus, and hence there is no chance that the DNA (genetic material) in our bodies will be affected, modified or mutated

What do we see in the future for other mRNA vaccines?

The future of mRNA vaccines for other diseases is bright. This technology can eventually be used to develop protection for different diseases using one shot and hence lessening the need for the administration of multiple injections. 

Away from vaccines, the mRNA technology can be also used to develop and boost the immune system to fight precise cancer cells in the oncology field.