COVID-19 vaccines can be divided into three types: mRNA vaccines (using the RNA acid sequence), vector vaccines (based on non-infectious fragments of other viruses) and subunit vaccines (containing proteins purified virus in the formulation). All preparations are administered intramuscularly, usually into the muscle of the upper arm.
After vaccination, it is advisable to wait 15-30 minutes to eliminate the potential risk of adverse reactions, including anaphylactic shock.
For all vaccines – check it out – www, the most common side effects were injection site pain, fatigue, headache, muscle aches and chills, joint pain, injection site fever and swelling. These effects were generally mild to moderate in intensity and resolved a few days after vaccine administration.
These are the latest generation preparations, although research on them has been ongoing for about 30 years. With mRNA vaccines, instead of injecting viral proteins, our bodies use instructions to create them themselves. These vaccines include preparations from Pfizer/BioNTech, Moderna and the German vaccine CureVac, which has not yet been approved.
Vector vaccines. Vector preparations are of an older generation than mRNA. They consist of a unique, recombinant and replication-deficient adenoviral vector. They have been modified to elicit an immune response from the body upon contact with the virus. These include preparations from companies: Astra Zeneca, Johnson&Johnson and Sputnik V (an agent used in Russia).
Subunit vaccines. Subunit vaccines contain a viral protein against which antibodies are produced. The protein in this vaccine is produced in butterfly cells and the immune response is enhanced by a substance from soapwort. An example of this type of vaccine is the two-dose preparation Novavax, not yet approved in the United States.
Have you already made the decision to get vaccinated against the coronavirus, or are you still thinking about it? We've put together the most important information about the types of coronavirus vaccines for you, to help you make the most informed decision possible.
What are the types of coronavirus vaccines?
mRNA vaccines. It is a vaccine technology based on mRNA matrix ribonucleic acid. And what is mRNA? This is the matrix that cells use to make proteins. This type of coronavirus vaccine uses a small portion of mRNA to trigger an immune response. The mRNA contains the protein code for the virus, which, when it reaches the body's cells, begins to produce the appropriate protein. This allows the immune system to activate a protective immune response without causing disease. It is in this category that the Pfizer and Moderna vaccines fall.
Pfizer coronavirus vaccine. The Centers for Disease Control and Prevention (CDC) states that the Pfizer BioNTech COVID-19 vaccine is suitable for people over the age of 16. It should be administered twice, 21 days apart. The vaccine should not be used by people who have ever had a serious allergic reaction to any of its components.
Side effects, as identified in the clinical trial, after administration of this vaccine include pain, swelling and redness of the area where the injection is given (i.e. the arm) and chills, fatigue, fever, and headache (more common after the second dose of the vaccine). Most of these adverse symptoms in the subjects were mild or moderate. These symptoms usually disappear within seven days of vaccination.
Clinical trials have proven that the vaccine is 95% effective.
In practice, that means it prevented that percentage from getting COVID-19, and if anyone did get the disease, they were less likely to get serious illness than those who got a placebo. Subjects included 35% people with obesity, 8% people with diabetes, and 8% people with lung disease.
Moderna's COVID-19 vaccine. Moderna's vaccine should be given to people aged 18 and over, and dosed in two batches, 28 days apart. It is injected into the shoulder muscle, similar to the Pfizer vaccine. This vaccine should also not be administered to people allergic to any of its components. Such an allergic reaction includes hives, swelling, or respiratory distress within four days of vaccination (distress also includes wheezing).
The majority of people who participated in Moderna's clinical trial (82%) were at higher risk of contracting coronavirus due to their profession. It should be mentioned that 25% of them worked in the health sector and were in places where many people were infected with SARS-CoV-2 daily.
In addition, 22% of study participants had one of the high-risk conditions, namely lung disease, heart disease, diabetes, liver disease or HIV infection. So how effective was the Moderna vaccine in this study? The effectiveness was determined to be 94% – also in people with comorbidities. Few of the clinical trial participants were hospitalized, but this happened much less frequently in those who received the vaccine than in those who received a placebo (i.e. a saline injection) .
Viral vector vaccines
How do the next type of vaccines for COVID-19 work? Vector vaccines use a part of the virus that has been modified to be non-life threatening and additionally non-infectious. Using an inactivated adenovirus (the virus that causes the common cold), genetic material is introduced into the cells of the body which instructs it to produce the protein COVID-19.
Once cells in the human body have already produced the SARS-CoV-2 protein, an immune response is triggered to fight it. The code in the vaccine only contains the information needed to produce a single COVID-19 protein, but does not cause the disease.