A: mRNA vaccines contain a message which instructs your cells to make a protein shaped like a small part of the virus. This does not affect your DNA, and it happens temporarily and locally at the injection site.
In your body, your DNA makes messenger RNA to make proteins. Your DNA has all the information it takes to make you, you. Messenger RNA only contains the information it takes to make a certain protein. It is similar to an instruction manual to build a piece of furniture. Protein is built using the information from the mRNA and incorporating different amino acids as the building parts.
The mRNA vaccines from Pfizer and Moderna contain the mRNA to make one particular protein of SARS-CoV2–known as the spike protein. The mRNA is placed in tiny fat bubbles (aka lipid nanoparticles) so that the mRNA can get into our muscle cells. Once inside the cell, the mRNA tells our muscle cells to build the spike protein.
mRNA is not very stable. This means that it does not last within our bodies for very long. The fat bubble containing mRNA is also not very stable. The Pfizer vaccine needs to stay in the -80C freezer…which is -112F! Most doctor offices or pharmacies do not have a freezer that can stay this cold. The Moderna vaccine is more stable. It has to remain frozen for long term storage, but it is stable at 4C, roughly the temperature of a household refrigerator, for one month. This will allow for easier distribution of the vaccine, as many doctor offices and pharmacies have access to a refrigerator to store the vaccine.
The spike protein is recognized by our immune system. Your different immune cells have proteins (receptors) that fit the spike protein. These cells will start to make more copies of themselves. Your B cells make antibodies to recognize the spike protein, and T cells will help. SARS-CoV-2 uses the spike protein to enter your cells. By making antibodies against the spike protein, the antibodies would bind the virus to stop it from entering your cells.
his is called neutralizing immunity–immunity that prevents infection.
There are 2 doses of the mRNA vaccines. The first dose “primes” the immune system. This gets the initial response underway. The second dose “boosts” the immune response, to lead to higher levels of antibodies and spike-protein reactive T cells. The full effect of immunity delivered by the vaccine happens after the second dose.
Side effects of the mRNA vaccines included temporary fatigue, muscle pain, joint pain and headache in a percentage of patients. These side effects are caused by the immune system reacting to the spike protein. Although these side effects are uncomfortable, they do not seem to last very long and are certainly safer than contracting COVID-19, even in younger, healthy populations. The side effects were more common with the second dose of vaccine, which is when the immune response is being boosted. Your natural immune system responses are powerful, and when your immune system is in action you feel it!
A main advantage of mRNA vaccines is that they are faster to manufacture than other types of vaccines. . This is why the mRNA vaccines are ahead in development compared to the other vaccines. Making mRNA does not involve time-intensive steps like making and isolating proteins and then purifying the products. It does not involve the use of cells to make.
mRNA vaccines have been studied for many years, although if approved, the Pfizer and Modera vaccines will be the first mRNA vaccines available. Thanks to many years of development and improving on the technology, the mRNA vaccines are set to make an impact to protect us in the pandemic.