How Does the COVID-19 Vaccine Work?

Finally, after nearly a year of enduring a pandemic, the first vaccines have started to roll off the production lines and be shipped to hospitals, long term care facilities, and other locations receiving the vaccine. First, let's talk about how our bodies fight illnesses such as COVD-19, per the CDC. Our immune systems are the body's defense against harmful microorganisms and pathogens. You have probably heard of red blood cells, which carry oxygen to tissues and organs all around the body. Your body also makes white blood cells, which are the primary adversaries to infection. There are different types of white blood cells: macrophages, B-lymphocytes, and T-lymphocytes. Macrophages essentially swallow up or destroy germs and dead cells. Both B and T-lymphocytes serve as the defensive cells. B-lymphocytes produce antibodies and T-lymphocytes attack infected cells. Once the body has experienced an infection or illness it will remember it and will be more prepared to effectively fend off an attack if it shows up again. T-lymphocytes are essentially kept in reserve specifically for the purpose of fighting the illness again if it were to show up again.

If you have ever been vaccinated or are familiar with the vaccination process, you are probably aware that the vaccination you receive for the flu likely contains an inactive or weakened version of the disease. This familiarizes the body with the disease without giving it the full effect that could be harmful. There are multiple types of vaccines that have been distributed and are still being clinically tested. The two vaccines you have probably been hearing the most about are the Moderna and Pfizer mRNA vaccines. mRNA vaccines are a little bit different because of how they work compared to vaccines for other diseases. These vaccines do not inject you with a suppressed or inactive form of the disease. Instead, these vaccines supply your body with materials that make instructions to make a specific protein that is unique to COVID-19. Specifically, it makes a completely harmless portion called a spike protein. That's it! Only one, small, harmless piece of the virus and our bodies become trained to fight it off. Our cells copy the protein and recognize they should not be there, then create B and T-lymphocytes to fight off the virus if it were to enter the body in the future. There are consistent side effects of the vaccines, including some severe allergic reactions in rare cases. The most common side effects include pain at the injection site, fatigue, headache, chills, fever, and joint and/or muscle pain. However, these side effects are to be expected and are a sign that the immune system is responding in the correct manner. Scientists have stated that developing these side effects are part of the process of building immunity. It has also been noted that the immunity process can take more than two weeks to become immune. Therefore, it is still possible to contract COVID-19 within the first few weeks after being vaccinated.

mRNA vaccines are not something completely new, and according to the CDC have been researched for decades. They are appealing because they are easy to develop in a laboratory and do not require overly complicated materials. This allows for faster, more efficient production in the case of a pandemic, which we are currently experiencing. They have been used in studies involving zika, rabies, and the flu. Thanks to this previous research with other viruses and diseases, the process for engineering the vaccine for COVID-19 had somewhat of a head start. Once the genetic makeup of the virus was mapped, researchers could then begin the process of making the directions for your body to create the unique protein. There are other types of vaccines for COVID-19 that are not mRNA based. Protein subunit vaccines and viral vector vaccines are in or approaching phase 3 clinical trials, so they have not been approved for emergency use by the FDA. The protein subunit vaccines are somewhat similar to mRNA vaccines in that they inject harmless proteins from the virus for the body to recognize and build immunity to. This will give only a part, rather than the whole of the germ. The other type of vaccine that is still being tested is the viral vector. Vector vaccines contain weakened live viruses, not the one that causes COVID-19, but it has genetic material implanted in it from COVID-19. Our bodies then perform the same process as in the other two types of vaccines: receive instructions to make the unique protein to fight off the virus.

Currently, only the Moderna and Pfizer vaccines are being distributed. They both require 2 separate shots in the upper arm. The two Pfizer shots are taken 21 days apart, while the Moderna is taken 28 days apart. You might be wondering why you need two shots. The first shot is simply for protection and the second is to “get the most protection the vaccine has to offer.” Getting two shots rather than one is time-consuming and obviously takes up more resources. Luckily, there is one vaccine in stage III clinical trials that only requires one shot. Developed by Johnson & Johnson, the one-shot vaccine has become increasingly more anticipated. The company signed a contract with the federal government months ago and is still waiting on clinical results that can be announced to the public. It has also been reported that they are having production issues, not being able to meet the amount they were expected to. Hopefully, this one-shot vaccine can come sooner rather than later, and we can start fighting back against this virus more effectively.