There are 16 vaccines that the CDC recommends getting from birth through 18 years of age. An additional 17 vaccines are recommended from age 19 onward. Make that an additional 18 vaccines now that Covid-19 vaccines have begun being administered in the U.S., offering much of the world a glimmer of hope that there is light at the end of the pandemic tunnel.
But the Covid-19 vaccines from Pfizer and Moderna use a different technology than traditional vaccines–mRNA .
What Is an mRNA Vaccine?
In traditional vaccinations, the body is trained to recognize and respond to specific proteins produced by pathogenic viruses or bacteria. Depending on the traditional vaccine, a tiny live dose or sometimes an inactivated dose of the disease-causing organism (or the proteins produced by the pathogens) are introduced into the body to provoke an immune response.
What makes the Covid mRNA vaccines different is that they manipulate the body into producing the SARS-CoV-2 proteins. In other words, no viral fragment is introduced. Instead, your DNA is told by the messenger RNA to create the viral proteins.
mRNA is located inside each of the approximately 37.2 trillion cells in the human body. A pre-building block of protein, mRNA functions like a protein template; mRNA represents what the protein will consist of later on as it fully develops.
How Are mRNA Covid Vaccines Produced?
Researchers use synthetic mRNA of SARS-COV-2, the virus that causes the disease, Covid-19. This synthetic mRNA builds infectious proteins. The cells receive the “message” from the synthetic mRNA to build the virus proteins. From there, viral molecules are created.
Unlike SARS-COV-2 infection, however, the viral proteins created by synthetic mRNA are singular molecules; they don’t group together to form the actual virus. The hope is that a successful Covid vaccine will help the immune system recognize the solitary viral proteins and mount an effective immune response.
How Else Are Covid Vaccines Different Than Traditional Ones?
To understand the difference, first it’s important to differentiate between the two different types of immune reaction the body has at its disposal: innate and acquired immunity.
The innate immune system is your body’s first line of defence; it’s the immune system you’re essentially born with.
Innate immunity springs into immediate action when a potential pathogen invades the body. Your skin, the chemicals in your blood as well as immune system cells are all players in your innate immune system.
The main driving force behind the innate immune response is antigens. Antigens are foreign substances which induce an immune response in the body, thereby producing antibodies.
With a healthy immune response, antibodies render antigens harmless.
Adaptive immunity refers to how well your immune system responds to specific antigens. So if the innate immune response is producing antigens, the adaptive immune response refers to how potent the response is to antigens.
Much more complex in nature than innate immunity, the adaptive immune response first processes and recognizes specific antigens. Then, an army of immune cells such as T-cells, B-cells, Natural Killer (NK) cells, and macrophages attack the antigens. Should your body be confronted with the same disease-causing antigen in the future, your adaptive immune response relies on its memory to mount a specific response to a specific antigen.
(Unfortunately, as you get older, not only are you more at risk for memory loss, your adaptive immune system loses its memory. Seniors can take supplements to strengthen the immune system.)
Traditional vaccines exert most of their influence on the acquired immune response. But traditional shots also activate the innate immune response through substances called “adjuvants”, such as aluminum salts.
The Covid mRNA vaccines will likewise activate both acquired immunity and innate immunity, and the technology behind the novel vaccines promises to be easier to produce and distribute on a wider scale than traditional vaccines.
Perhaps the most well-publicized difference is that the Pfizer Covid vaccine needs to be frozen at minus 70 degrees Celsius (-94 Fahrenheit). (Moderna’s Covid vaccine also needs to be stored in sub-freezing conditions, albeit not as cold: minus 20 Celsius (-4 Fahrenheit).
What is the History Behind mRNA Vaccines?
The majority of research comes from the field of oncology, where mRNA from tumors are used to activate lymphocytes such as tumor-killing T-cells. (T-cells are produced in the thymus gland, one of the most overlooked components of a healthy immune system.)
Researchers involved in the development of Covid vaccines hope that T-cells will mount a strong response to viruses. Viruses can be covert killers. They like to hide in cellular components and replicate. By activating T-cell response, the Covid vaccine will, fingers-crossed, eliminate infected cells.
But before targeting infected cells for elimination, the acquired immune system first needs to produce antibodies. When antibodies are produced, the virus is targeted for destruction, and it’s up to B-cells, which are produced in bone marrow, to accomplish this task.
What Don’t We Know Yet About Covid Vaccines?
In one word, lots. Despite the promising results from the Pfizer and Moderna vaccine trials (each one reported over 90% efficacy), the outcomes were self-reported by the pharmaceutical companies; results of the trials were not published in peer-reviewed journals. We also don’t yet know how long immunity will be last, or even if getting a Covid vaccine will provide immunity in the first place. Getting a Covid vaccine may prevent you from becoming seriously ill, but it doesn’t guarantee immunity to it.
It’s also important to understand that despite the initial rollout of Covid vaccines in the U.S., the vaccines haven’t been fully approved yet; full approval is expected mid-2021. Nonetheless, the U.S. Surgeon General, Jerome Adams, says, “It’s been authorized. And that means that scientists, the FDA, and independent scientists feel that the benefit far outweighs the risk.”
