Explaining the Issues: The COVID-19 Vaccine

On December 11 th , 2020, the Pfizer-BionTech COVID-19 vaccine was authorized for emergency use in the United States by the Federal Drug Administration (FDA). A week later the Moderna vaccine was also given emergency authorization. With the approval of these 2 vaccines, many questions have been raised on whether or not the vaccines are safe given how fast they were developed and whether or not they will actually work.

First, let’s get into the breakdown of these two vaccines. Both are very similar with some slight differences. Both the Pfizer and Moderna vaccines are mRNA vaccines. But what exactly is mRNA? Also known as messenger-RNA, mRNA is genetic material (similar to DNA) that has ‘instructions’ to build proteins. In the coronavirus vaccine, the mRNA has instructions for the spike protein on the surface of SARS-CoV-2, the virus that causes COVID. By introducing the genetic material for the spike protein into your cells, structures in your cells, called ribosomes, will ‘read’ this ‘instruction manual’ and start building the protein. The spike protein will then be expressed on your cells. Your immune system will recognize is as an invader and start building antibodies against it, so if you do get infected with COVID, the antibodies against it are already there, and your body will be able to fight it off quickly and efficiently, before illness develops. The key here is that giving your body the genetic material to build the spike protein will not infect you with coronavirus, it will just allow your body to build antibodies to fight it off. In addition to the mRNA material, both COVID vaccines need a way to get the mRNA into your cells. This is done through lipid nanoparticles, which encase the mRNA into tiny capsules, so that it can be delivered to your cells. Here is where the two COVID vaccines differ slightly. While both use lipid nanoparticles to deliver the mRNA, Moderna has been developing nanoparticles for use in other mRNA technology for more than 10 years, while Pfizer hasn’t. As a result, Moderna’s lipid nanoparticles are slightly more stable, meaning that the Moderna vaccine doesn’t need to be stored at the extremely low temperatures that the Pfizer vaccine does. (Pfizer’s vaccines need to be stored at -70 degrees Celsius, colder than Antarctica, while Moderna’s vaccines need to be stored at -20 degrees Celsius, according to NPR.)

One of the most common concerns about the COVID vaccine is how fast it was developed. Past vaccines have taken up to 10 years to develop and get authorization, so how was this vaccine developed and approved in a little less than a year? According to Medical News Today, the short answer is that scientists didn’t have to start from scratch to build this vaccine. Coronaviruses have existed for years, COVID-19 is just another virus in this family. Other coronaviruses have also caused epidemics such as SARS (Severe Acute Respiratory Syndrome) in 2002 and MERS (Middle Eastern Respiratory Syndrome) in 2012. There are even some coronaviruses that cause the common cold. At the time of these epidemics, scientists were working on vaccines for these diseases so there is already existing research on coronaviruses and their genetic material and life cycle. In addition, both Moderna and Pfizer are pioneers in the field of mRNA technology and this type of technology has been researched and worked with for many years. In addition to being able to build on existing research, the COVID vaccine developed quickly because of worldwide collaboration. Many researchers dropped what they were working on in order to devote all their time to making a vaccine. Being able to quickly sequence the genome for SARS-CoV-2 also greatly sped up the process; the full genomic and viral sequence of COVID was uncovered in January 2020, less than a month after the first case was reported in Wuhan, China. Past vaccine development has also been hindered by lack of funding and a lack of clinical trial volunteers. Both of these issues weren’t a problem with COVID because thousands of people volunteered to be part of clinical trials and multiple government agencies, such as the National Institutes of Health, provided massive grants to biotechnology companies in order to prepare a vaccine for immediate use

Another major concern from the COVID vaccine is the fact that this is the first mRNA vaccine to be approved by the FDA. Past vaccines, such as the flu vaccine, have used a deactivated or weaker version of a virus in order to stimulate an immune response in the human body. In fact, there are COVID vaccines in the works that do just that such as the Novavax vaccine being developed by a Maryland biotechnology company, and one vaccine being developed in Russia. Because the COVID vaccine is the first mRNA vaccine to be approved, there are doubts about the efficacy of the vaccine. However, both Pfizer’s and Moderna’s vaccine are more than 90% effective in protecting against COVID-19. According to the New England Journal of Medicine, in clinical trials the Pfizer-BioNTech vaccine gave 95% protection against the coronavirus in people ages 16 and older. The Moderna vaccine gave 94% protection against COVID infection in people ages 18 and older. Another concern is side effects. Given how fast these vaccines were developed, many people are concerned about possible long term side effects of the vaccine. According to the CDC, common side effects of the COVID vaccine are pain and swelling at the injection site, fever, chills, fatigue and headache. All of these side effects are signs that your immune system is working. Doctors and scientists are not very concerned with long term side effects because most side effects of vaccination show up within 2 months. However, the CDC has stated that they are continuing to monitor clinical trial participants and ask them to report any symptoms that may come up. In addition, healthcare professionals are much more concerned with the long-term effects of COVID-19 infection, such as long-term brain damage and lung problems.

Lastly, because one of the vaccine’s major components is mRNA genetic material, many people are concerned that the vaccine can change your genetic makeup. However, the mRNA never enters the nucleus of your cells where your DNA is. The mRNA is delivered into the cytoplasm of the cell, where the ribosomes are. As soon as the mRNA gives the ribosome the ‘instructions’ on how to build a spike protein the body breaks it down; it can’t enter the nucleus and effect existing genetic material.

The development of the COVID-19 vaccine in a little under a year is a sign of how far technology in the world has come and what can be accomplished when the entire scientific community works together to achieve one goal. While many people are concerned about the efficacy and side effects of the vaccine, clinical trial data and results have shown promising results. Both the Pfizer and Moderna vaccines require 2 doses, 21 days and 28 days apart, respectively, and are more than 90% effective in stopping COVID infection. More trials do need to be conducted to test the vaccine in different populaces such as children and pregnant women, but the development of an effective vaccine is a light at the end of the tunnel to many people around the world.