COVID-19 Vaccines
- Vienne V
- Dec 28, 2022
- 5 min read
Introduction to Genetically Engineering Vaccines:
Genetic engineering is proving useful in what might help end this global pandemic: the COVID-19 vaccine. It can take years to develop a vaccine for a new virus; previous vaccines such as the flu vaccine took the more traditional approach. Flu vaccines are made by growing weaker versions of viruses in chicken eggs or insect cells; after the viruses have grown, scientists extract the pieces of the right influenza. It can take up to months or years to produce the correct antigen for the correct virus.
However, because COVID-19 is spreading too quickly and months and years would be much too long to wait for a vaccine, the new COVID-19 vaccine is now based on genes. Scientists must use the virus’s genome to get the right information, and use that information to create a blueprint of the antigens they need for the vaccine. When they have found the correct antigens, the scientists have a blueprint made of the DNA or RNA of the virus; the researchers then insert that DNA or RNA into human cells. Once the RNA/DNA has entered the human cell, the cell responds as it does with influenza or other viruses. It uses the instructions in the DNA/RNA to make more virus antigens that the immune system will have a reaction to.
As of March 2021, the COVID-19 vaccines that have been created for the pandemic are the INO-4800, Moderna, Johnson & Johnson, AstraZeneca, Pfizer-BioNTech, and Novavax.
INO-4800 Vaccine:
SARS-CoV-2 has a protein called a “spike protein” that is attached to the outside of the virus, and that “spike protein” is what allows the virus to attach to a human cell and hijack the cell to recreate itself. Many of the laboratories creating the COVID-19 vaccine want to train human cells to make this spike protein; there are currently three ways to deliver the spike protein to the cell. The first way is a DNA plasmid, which is usually a ring-shaped molecule; the DNA plasmid would be useful in delivering the spike-protein blueprint to the cell, as if a virus begins to mutate, scientists can immediately change out the mutating plasmid for a new one. For example, a company that is currently using the DNA plasmid approach to create the COVID-19 vaccine is Inovio Pharmaceuticals in Pennsylvania, or the INO-4800 vaccine, as well as the upcoming AstraZeneca vaccine that may receive authorization in April 2021.
Moderna and Pfizer-BioNTech Vaccine:
The next way to trick a human cell into creating COVID-19’s spike protein is the RNA vaccine. While the DNA plasmid works well, using the RNA vaccine will be much faster, as it skips the step of using the DNA plasmid to enter the cell. Instead of using a plasmid to insert the DNA or RNA of the spike protein into the cell, scientists can simply put the blueprint of the spike protein into a strand of RNA. The RNA strand, carrying the blueprint, is then put into a lipid—usually oily molecules that make oils or body fat—which have a much easier time passing into cells. Research shows that using the RNA vaccine approach will be easier to make antibodies, which will help if it creates an antibody against the spike protein and COVID-19. Both the Pfizer-BioNTech and Moderna vaccines are using the mRNA vaccine approach.
Johnson & Johnson Vaccine:
The final way to trick a human cell into creating COVID-19’s spike protein is by inserting the protein’s DNA blueprint into the cell of a common cold virus. This common cold virus carries the spike protein DNA within it, and hijacks the cell to help create the protein. Since common cold viruses are good at slipping into cells, this adenoviral vector vaccine might work. However, many scientists are concerned about how the human body might react to this type of virus. For example, since the human immune system can recognize some types of common cold viruses, it could attack the vaccine before it replicates and takes effect. Another worry is that perhaps the adenovirus will replicate and cause a mutation of COVID-19 within the body. One company that is creating an adenoviral vector approach to creating a COVID-19 vaccine is the Johnson & Johnson viral vector vaccine.
COVID-19 Vaccine Process:
Since each of the vaccines are different, they are also inserted into your body in different processes. Understanding the process of each vaccine being inserted into your body will also help you decide which you would like to take or will help your body the most. Let’s start off with the Moderna, Pfizer, and Johnson & Johnson vaccines, as they have been approved by the CDC (Centers for Disease Control and Prevention) and have been used in vaccination centers around the United States. Moderna is an mRNA vaccine, as covered previously, and it is given in 2 shots, which are taken 28 days apart. This shot will be in the upper arm muscle, and the Moderna vaccine is recommended for people 18 years old or above, and have a 94.1% efficiency. The Pfizer-BioNTech vaccine will also be given in 2 shots, in the upper arm muscle, but the two shots for the Pfizer vaccine will be spaced 21 days apart. From the Pfizer trials, it has been shown to have a 95% efficiency and is recommended for people 16 years old or above. The Johnson & Johnson vaccine is delivered in one shot, opposed to Moderna and Pfizer, and is also given in the upper arm muscle with a 66.3% efficiency. However, despite its lower efficiency against COVID-19 compared to Pfizer and Moderna, it has a 100% efficiency against death due to the virus. The Johnson & Johnson vaccine is recommended for people 18 years old or above. As for the INO-4800, Astrazeneca, and Novavax vaccines, they have not received authorization in the United States as of March 2021.
Risks of the COVID-19 Vaccine:
Now that we have gone over the different types of vaccines and how they work within the human body, we should also cover the risks of each SARS-CoV-2 vaccine. For example, some common side effects of taking the Moderna, Pfizer, and Johnson & Johnson vaccines are pain, redness, and swelling in the arm where you received the COVID-19 vaccine. Other side effects are tiredness, headaches, muscle pains, chills, fevers, and nausea. After the vaccination, there have been rare cases of anaphylaxis, or severe allergic reactions. The FDA requires that any death after receiving the COVID-19 vaccine be reported to VAERS; after 126,000,000 vaccines given from December 14, 2020 and March 22, 2021, there have been 2,216 deaths reported, or about 0.0018%. The CDC has stated that information such as death certificates, autopsy, and medical records have shown that the vaccines did not contribute to the deaths.
While the AstraZeneca vaccine has been developing and currently being tested to be released around this April, recent studies in Europe showed a deadly but rare side effect from receiving the AstraZeneca vaccine— which is increased risk in blood clots. Due to this side effect, thirteen countries have decided to suspend using the AstraZeneca vaccine. Dr. Joss Reimer, the lead of Manitoba’s vaccination task force, has said that they have stopped using AstraZeneca on people under 55 for the time being—and that the blood clot side effect is very rare, in the range of one in 100,000 or one in 1,000,000.
The COVID-19 vaccine—and the three different ways to approach it—are examples of how much genetic engineering has advanced in the past few years. Instead of having to wait months or even years to create a vaccine that might return life to normal, scientists can use genetic engineering to create a vaccine in a few months, which may be the fastest a vaccine has ever been created.
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