Above: NY Nurse Sandra Lindsay getting the first COVID-19 vaccination in the U.S.
With the arrival of the COVID-19 vaccine comes a lot of questions. How does it work? What are the ingredients? Are there side effects? Is it safe? How is it different from other vaccines?
Historically, vaccines are derived from live or dead viruses and injected into the body. The immune system recognizes the virus as an invader and responds as such. The body makes cells and antibodies to attack the virus. The ‘mapping’ of the virus is remembered by the body and if it is introduced again (by exposure, not the vaccine), the immune response will be the same. Seems relatively simple, right?
Why is the COVID-19 Vaccine Different?
The SARS-CoV-2 vaccine is the first mRNA vaccine to be used. The method in which it provides immunity is a bit different from traditional vaccination. The process starts with a synthetic strand of genetic code called messenger RNA, or mRNA. Our cells already store special coded instructions for making protein. When a cell needs a specific protein it copies the correct instructions onto a mRNA molecule. The cellular structure called a ribosome then travels along the strand of code, processes it, and produces the appropriate pieces (called polypeptides) to start building the protein.
Without getting too technical, proteins are essential workers for the body. They have a huge role in many body functions, and without them we could not survive. Around 30 years ago, scientists realized they could produce mRNA in a lab, deliver it into the human body, and make proteins to fight certain diseases and illnesses. Through further research, they realized that the synthetic mRNA could only enter the body undetected if they hide it in a fatty nanoparticle. Otherwise, it could produce a severe inflammatory response as the immune system attempted to destroy the foreign particle (the synthetic mRNA).
How does the COVID-19 Vaccine Work?
Both the Pfizer and the Moderna vaccines contain strands of synthetic mRNA that carry the code for the ‘spike protein’ of coronavirus housed in a fatty nanoparticle to prevent the body from attacking it. This is a reference to the ‘spikes’ seen on the outside of a COVID-19 viral cell.
The vaccine delivers the mRNA to your cells with instructions for building these ‘spike proteins’. The cells start producing ‘spikes’ and the immune system is then awakened by the presence of these ‘spikes’, which are unrecognizable to the body. The immune system launches a full attack and creates cells to destroy the ‘spikes’, thereby giving the body immunity to COVID-19.
The immune response will be triggered to release killer T cells, versus just antibodies that traditional vaccines produce. This is because the mRNA has the ability to get into the cells, whereas dead or weakened viruses do not. T cells can recognize and destroy the virus inside the cell by scanning its surface for proteins that are being produced. Antibodies do not have that capability.
The vaccine does not have the ability to enter the nucleus of a cell, where our DNA is stored. And, the mRNA that was deposited usually breaks down within a few days after doing its job.
Can the COVID-19 Vaccine Cause an Allergic Reaction?
Unlike the flu virus, which contains allergens like eggs, the COVID-19 vaccine most likely will not elicit an allergic reaction in the majority of the population.
What are the Ingredients in the COVID-19 Vaccine?
The first ingredient is mRNA. This delivers the code to build spikes (glycoproteins) of SARS-CoV-2 to our cells. The second ingredient is a combination of lipids that form a ball to permeate the phospholipid bilayer of our cells (and hide it from our immune system). The lipid ball will fuse with the cell membrane and deposit the mRNA into the cytoplasm. The third ingredient is a variety of ‘salts’ (Potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dehydrate) that stabilize the pH of the vaccine. The fourth ingredient is sucrose, which is used to stabilize the vaccine while it is stored and transported at sub-zero temps. Right before the vaccine is given, a small amount of sodium chloride (0.9 NS or normal saline) is added to further stabilize the pH of the vaccine.
For more answers about who should or should not receive the vaccine and tons of information, check out Pfizer’s Fact Sheet for Recipients and Caregivers.
