How do vaccines work?
As the COVID-19 pandemic continued for a prolonged period, it has been said that various vaccines were invented to prevent COVID. Pfizer was the first company that has been reported to create the vaccine, followed by other companies such as AstraZeneka and Moderna. If we look at the news, we see people being vaccinated and various controversies about the vaccines themselves. Such inquiry arises from here: what are vaccines and how do they work?
Vaccines are defined as an injection to stimulate the body’s response against a specific infectious agent. They are specifically designed to prevent someone from having the disease by injecting people with portions of the virus or a weakened version of the virus. However, why would they do so? In order to understand such a reason, we need to understand the basic mechanism of our immune system. As antigens invade our body, our immune system activates to prevent the disease from taking over our body. One of the processes involves B-cells creating antibodies, a specific type of proteins that are specialized in binding into antigens and preventing their actions. Other than just preventing antigens from taking action, antibodies may also trigger opsonization. Opsonization is a process of antibodies tagging into the antigen so that it facilitates phagocytosis, a process of leukocytes eating the antigens.
Vaccines’ mechanism of injecting antigens into our body directly uses such aspects of our defense mechanism. As weaker antigens enter our body, they maintain the information (RNA or DNA) that they have so that they can be used by B-cells to create antibodies, but they lack the strength to cause casualties in our body due to them being weakened in prior. The following makes it so that our body can create antibodies for certain diseases by exposure to a weaker version of the disease. This will, later on, help our body to go against the stronger version of the antigen, thus leading to a more accessible cure of the disease that might not even be noticed by the host (person).
As we just talked about the basic mechanisms of vaccines, now let’s talk about various types of vaccines. One of the most common types of vaccines is Inactivated vaccines, a type that uses dead particles of antigens in order to trigger our defense mechanism. Because the antigen itself is dead, the following vaccines usually cause fewer side effects after injection, although they do have less effectiveness as a vaccine. Therefore, it requires various booster shots, or future injections in order to maintain immunity against a disease. The following type of vaccine is used against common diseases such as flu or polio. Another type of vaccine is Live-attenuated vaccines. These types of vaccines use weaker versions of the antigen that is alive. Because the following vaccines resemble the actual antigens better compared to inactivated vaccines, live attenuated vaccines provide longer and stronger immunity against the disease, but it has higher side effects compared to inactivated vaccines. Live attenuated vaccines are also used against common diseases such as smallpox, chickenpox, and yellow fever. The last type of vaccine is the mRNA vaccine. The following vaccine uses mRNA, a type of RNA that is used to trigger and direct protein production in our ribosomes, as a method to provide immunity. The following type of vaccine is a more recent technique in creating vaccines and it is not fully completed compared to other methods, but it has been recently used in important cases such as COVID-19. As the following vaccine uses mRNA, the production is much cheaper and faster, although it may lack strong immunity against diseases.
References:
“Different Types of Vaccines.” History of Vaccines RSS, https://historyofvaccines.org/vaccines-101/what-do-vaccines-do/different-types-vaccines.
Office of Infectious Disease and HIV/AIDS Policy (OIDP). “Vaccine Types.” HHS.gov, 6 Dec. 2021, https://www.hhs.gov/immunization/basics/types/index.html.
“Types of Vaccines.” Immunisation Advisory Centre, 17 Sept. 2020, https://www.immune.org.nz/vaccines/vaccine-development/types-vaccines.
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