The Science Behind the COVID-19 Vaccine

By Christina B. '23

After a long year of struggle, adaptation, and persistence, the first dose of the highly anticipated COVID-19 vaccine was administered in New York City on December 14, 2020 to a Critical Care nurse. This first of the two required doses marked not only the foreseeable end of this pandemic, but also the first public distribution of an mRNA vaccine in history. Now, the number of vaccinated citizens has grown to approximately 23 million people, with about 5 million having received both doses. As this number continues to grow, questions about the effectiveness of the vaccine arise. Luckily, the science behind the vaccine can be utilized in finding the answers to many of these questions.

Knowledge of cellular biology is key in understanding how an mRNA vaccine functions. Located in the nucleus of the cell, Deoxyribonucleic acid (DNA) contains instructions for all the processes that occur within an organism. Before “reading” these instructions, the cells must break down the DNA into messenger Ribonucleic Acid (mRNA), which puts the DNA information into a format the body can understand. According to the CDC, the COVID mRNA vaccine uses this process to instruct cells into creating a harmless piece of spike protein that mimics those on the surface of the virus. When the immune cells see this spike protein, they produce antibodies to protect our bodies from the foreign substance and will remember this procedure when coming into contact with the actual virus. The second dose works identically to the first, but having the body undergo the same process twice ensures the maximum effectiveness of approximately 95% after two doses from both Moderna and Pfizer vaccines. Mayo Clinic warns that vaccination may result in side effects including a slight fever and body aches, but only in response to the immune system learning to fight the virus. No part of the vaccine contains the actual virus, verifying that it is not possible to contract the virus from receiving the shot.

While some cannot wait to receive the vaccine, others have their doubts due to a lack of trust in the healthcare system. Herd immunity, which occurs when the spread of a virus becomes unlikely due to a high percentage of immune citizens, can be achieved through natural spread of the virus, but this would result in an extraordinary number of deaths. World health officials calculate COVID-19’s high mortality rate to be 3.4%, in comparison to influenza’s less-than-1%. On the other hand, vaccinating 70%-90% of the population can also result in herd immunity without the risk of an excessive number of deaths. Not everyone can receive the vaccine due to compromised immune systems, so Dr. Ashley Drews, an infectious disease specialist suggests, “those of us who can get vaccinated need to do our part to protect those who can't.”