The Immune System Essay Example

There are two parts of the immune system: the innate immune system which is inherited, and the acquired immune system which is developed throughout your life. This system is known as the ‘rapid response system’ as it is the first to respond to an invading pathogen. The innate immune system provides a physical barrier to our bodies in order to protect us from harmful germs. When a foreign body is detected, the cells of the immune system surround and cover the pathogen, and it is killed inside the immune cells. 

The acquired immune system creates antibodies, which are used to protect the body from one specific antigen. Antibodies are proteins which find foreign substances including viruses and bacteria in order to neutralize them. Even after exposure to this certain substance, the antibody continues to circulate in the blood in case of further exposure to the antigen. The acquired immune system will change and adapt throughout your life, allowing antibodies to be produced in order to fight new diseases. 

Vaccines are used to protect from diseases without ever coming into contact with them. Vaccines utilize the immune system's natural defense to build resistance to a specific antigen, and strengthen the immune response. Traditionally, vaccine producers have opted to manufacture inactivated or live attenuated vaccines. These vaccines use a germ that has been weakened or killed, so that the disease does not actually infect the body, and instead initiates immune response to produce antibodies. 

mRNA vaccines can be a safer, more effective method of triggering this same immune response. One specific form of RNA is messenger RNA. mRNA first copies genetic information regarding the construction of a specific protein from the DNA in the cell nucleus. mRNA then leaves the nucleus, and moves to the cytoplasm, the liquid that fills the inside of the cell. There, the mRNA is scanned by an organelle called the ribosome. The ribosome reads the base sequence encoded in the mRNA, and transforms this complex genetic code into corresponding amino acids, producing proteins. 

mRNA vaccines contain messenger RNA suspended in a lipid nanoparticle (LPD) formulation. The mRNA in the vaccine contains the blueprint for our cells to build a portion of the virus, typically the spike protein on the outside of the virus, on their own. The injected mRNA reaches the cell, and is scanned by the ribosome. The spike protein is then produced, and is released from the cell. Once the immune system recognises the antigen as a foreign body, an immune response is triggered, and the specific antibody is created.  

Although mRNA technology has not been available for the public until the production of COVID 19 vaccines, these discoveries are not recent. Messenger RNA was actually discovered nearly 60 years ago in the early 1960s, and research on how to deliver mRNA into cells began in the 1970s. Twenty years later, the first mRNA influenza vaccine was tested on mice. While messenger RNA technology had been decades in the making, it was not until 2013 that the first mRNA vaccine for rabies was tested on humans. The main reason for this delay was due to mRNA degrading too quickly in the body, not allowing the mRNA to be delivered into the cells, where it could be transformed into protein. New advances in nanotechnology led to the solution of this problem. These fatty droplets coated the mRNA, and helped deliver it into the cells, protecting it from degradation. These nanoparticles were first used to fight the Ebola virus, but had no commercial development in the United States. 

On December 11th, 2020, the Pfizer vaccine was authorized for emergency use to those 16 and older, and the Moderna vaccine followed soon after. Pfizer became the first mRNA product to receive full approval from the Food and Drug Administration (FDA). Typically, developing a vaccine can take anywhere from 9 to 17 years, while the COVID vaccine took merely one year to achieve FDA approval. Although this was an incredibly speedy process, the development of the vaccine was not dangerously rushed. Instead, previous research on mRNA technology and a prior knowledge on similar Coronaviruses allowed scientists to quickly discover a vaccine to fight COVID 19. 

It is likely that the next mRNA vaccine to be produced will be for other viral diseases, including the flu. A new mRNA flu vaccine could provide wider protection than current inactivated flu vaccines. These vaccines are a guessing game, scientists must decide which strain of influenza will be the most predominant that year, and produce vaccines to fight that strain. Because the research can take months, this assumption is not always accurate. An mRNA flu vaccine could eradicate this gamble. Pfizer has recently partnered with German BioNtech to develop a more effective flu vaccine. This vaccine would be quicker to produce, not only aiding scientists to more accurately foresee the dominant influenza strain, but vaccines can be rapidly manufactured and exported to fight an emerging strain. While incubating live attenuated or inactivated vaccines in a lengthy process, changing mRNA is quick and easy. Similar messenger RNA vaccines continue to emerge, with 3 mRNA flu vaccines in clinical trials, and 10 in the preclinical stage. 

Human Immunodeficiency Virus, or HIV, is a virus that is spread through the contact of certain bodily fluids. This virus attacks the cells which fight infection, causing the body to become more vulnerable to disease. The body's natural immune system is not strong enough to fight HIV, so once a person is infected, they have it for life. Without proper treatment, HIV infection can lead to AIDS, Acquired Immunodeficiency Syndrome. However, current antiretroviral therapy allows those with HIV to live long, healthy lives, and prevents transmission to a sexual partner. 

Although HIV is incurable, there is hope that it may be preventable through vaccination. Research to develop a vaccine began as soon as researchers discovered that HIV causes AIDS. Initially, the development appeared simple. However, nearly 40 years later, there is still no vaccine. There are currently several HIV vaccines in clinical trials, one displaying notably promising signs in animals. Dr. Paolo Lusso of NIH’s National Institute of Allergy and Infectious Diseases led a team in the development and testing of an mRNA HIV vaccine. This vaccine delivers instructions to create two key HIV proteins: Env and Gag. These proteins assemble to form a non infectious, virus like particle that stimulates immune response similar to that of natural HIV infection. 

Initially, this vaccine was tested in mice. After two injections, all animals acquired HIV neutralizing antibodies. Their reaction closely simulated a natural infection, and marked a major progression in HIV vaccine research. The team later tested this vaccine on Macaques, a species of primate, which were injected with both a priming and several booster vaccines. The monkeys were then exposed weekly to HIV, and after 13 weeks of inoculations, two out of seven monkeys remained uninfected. Those that were infected had a delayed reaction, occurring after eight weeks on average, five weeks later than otherwise typical. Many similar vaccines are following this study, including one developed by Moderna that is entering clinical trials. 

As messenger RNA technologies prove to be effective and efficient in emerging studies, researchers have focused their attention on using these vaccines to treat cancer. Small trials on mRNA in cancer treatment in the past decade have shown such promising results that both Pfizer and Moderna drew on these studies in their developments of a COVID 19 vaccine. Many researchers feel confident that mRNAs success in controlling the COVID 19 pandemic will give mRNA cancer treatments the necessary boost to advance. “The funding and resources that are flowing into mRNA vaccine research will help the cancer vaccine field,” says Patrick Ott, M.D., Ph.D., director of the Center for Personal Cancer Vaccines at the Dana-Farber Cancer Institute. Although no mRNA cancer vaccines have been approved by the FDA, tests on various cancers are in clinical trials. These vaccines will synthesize proteins present in tumor cells, creating antibodies to neutralize the tumor. Some trials are testing a vaccine combined with drugs to enhance the body's immune response.