The reports of two different COVID vaccines beginning to become available to the public is very encouraging news in the fight against this pandemic. But with all the information (and misinformation!) flying around out there, some people are understandably a bit hesitant to roll up their sleeves for the jab.
You may have heard that the vaccines contain genetic material and have concerns about that. Just how does this new vaccine technology work anyway? Let’s take a closer look.
The COVID vaccines are made using a new method known as mRNA technology. To understand how any vaccine works, you need to know just a bit about how your immune system functions.
When viruses or bacteria attack your body, they invade and then multiply. This invasion triggers your immune system to respond. Besides red blood cells which carry oxygen, your blood also carries an army of white blood cells for fighting infections. These white blood cells have several different kinds of soldiers consisting mostly of macrophages, B-lymphocytes and T-lymphocytes.
Macrophages engulf and digest the invading germs, leaving behind pieces of the invaders called antigens. Your body sees these antigens as foreign and identifies them as the enemy. Next, the B-lymphocytes actually produce the antibodies that attack the antigens remaining from the macrophages. T-lymphocytes work a bit differently, in that they go after and attack body cells that have already been infected.
When you get an infection from a germ your body has never encountered, the immune system goes to work making antibodies and fighting it off. After you recover, your immune system “remembers” how to fight the infection and will quickly make antibodies if the germ attempts to invade again.
The goal of all vaccines is to teach your immune system to recognize the invader. With the older vaccine technologies, vaccines were produced in several ways using weakened but live viruses and bacteria (measles, mumps and rubella), inactivated viruses (polio) and even using weakened toxins produced by the bacteria itself (tetanus) that “teaches” the body how to respond.
Let’s look at the mRNA technology behind the COVID vaccines. Viruses are made up of a core, consisting of either DNA or RNA, wrapped in a protein coat. To make the protein coat, the core RNA or DNA of the virus makes mRNA (messenger RNA) which makes the proteins for the coat. You can think of mRNA as a set of instructions for the cell to carry out.
Even though mRNA vaccines are being hailed as a new technology, researchers have actually been working on mRNA vaccines for nearly 30 years, learning how to modify the mRNA so there were no untoward reactions, as well as how to envelop the mRNA in microscopic molecular capsules so it would not be destroyed in the bloodstream.
When COVID-19 emerged, researchers in China quickly analyzed it, then published this information on the internet. Scientists all over the world immediately began to work on an mRNA vaccine for the virus, building on the decades of previous work.
In the COVID-19 virus, there is a part of the protein coat known as the spike protein. Scientists were able to analyze this spike protein to see exactly what sort of mRNA it was made of, then they were able to synthesize this in the lab in large quantities.
Vaccines from both Moderna and Pfizer labs work by using a piece of the COVID mRNA spike protein which is injected into the muscle of the upper arm. Once the mRNA (the instructions) is inside the immune cells, the cell uses the mRNA blueprint to actually make the protein piece.
After that, the mRNA is broken down and destroyed by the cell so it cannot instruct the cell to make any more. The protein piece is then displayed on the surface of the cell, where it is recognized by the immune system as a foreign invader. The immune system goes to work producing antibodies and immunity for the person who has received the injection.