What are mRNA vaccines?
The new COVID-19 vaccines have been a topic of much conversation in recent weeks. Many people are excited and hopeful that the vaccines’ arrival marks the beginning of defeating the COVID-19 pandemic.
Along with excitement and hope, many people also have questions about the vaccines. Common questions have centered on safety and side effects. Learn more about why the vaccines have been deemed safe and what side effects could be experienced.
mRNA technology was in development for years before the COVID-19 pandemic, and the arrival of the new coronavirus provided vaccine manufacturers an opportunity to use it.
Making new vaccines the traditional way — using dead or weakened versions of the virus itself, which the body learns to identify and develop immunity to — can take years. mRNA vaccine development is faster than traditional production methods.
The mRNA COVID-19 vaccines contain instructions that cause the body to produce copies of just one part of the COVID-19 virus — a harmless protein. This protein by itself cannot cause COVID-19.
When these proteins are released in the body, the immune system identifies them as foreign and destroys them, while also making antibodies to detect and react to the protein and the virus that causes COVID-19.
After vaccination, if a live version of the COVID-19 virus enters the person’s body, the immune system remembers the protein and attacks the virus so it cannot reproduce and make someone sick with COVID-19.
The COVID-19 mRNA vaccines do not use the live virus that causes COVID-19 and cannot give someone COVID-19.
The COVID-19 mRNA vaccines do not affect or interact with the body’s DNA in any way. mRNA never enters the nucleus of the cell, which is where DNA is kept. The cell breaks down and gets rid of the mRNA soon after it is finished using the instructions to make the protein.
mRNA vaccines are held to the same rigorous safety and effectiveness standards as all other types of vaccines in the United States.
Other questions have been raised about vaccines in general — and how they work.
According to the U.S. Food and Drug Administration (FDA), vaccines work by mimicking the infectious bacteria or viruses that cause disease. Vaccination stimulates the body’s immune system to build up defenses against the infectious bacteria or virus without causing the disease.
Some vaccines contain weakened versions of a bacteria or virus, while other vaccines contain only part of the bacteria or virus. Other vaccines, called messenger RNA (mRNA) vaccines, direct the body to produce a small number of copies of a protein (or even just a piece of a protein) specific to the target organism, which causes the body’s immune system to react defensively once it detects this protein.
After vaccination, the immune system is equipped to respond quickly and forcefully if or when the body encounters the real disease-causing organism.
Both the Pfizer and Moderna COVID-19 vaccines are mRNA vaccines. Short for messenger ribonucleic acid, mRNA represents a new type of vaccine to protect against infectious diseases. Instead of putting a weakened or inactivated germ into the body, mRNA vaccines provide genetic instructions for the body’s cells to produce harmless viral proteins that create an immune response.
When these proteins are released in the body, the immune system identifies them as foreign and destroys them, but not before making antibodies to detect and react to the protein and the virus — in this case, the virus that causes COVID-19.
Then, later, if a live version of the COVID-19 virus enters the person’s body, the immune system “remembers” the protein and attacks the virus so it cannot reproduce and make someone sick with COVID-19.
Though mRNA vaccines may be new to the general public, researchers have been studying and working with mRNA vaccines for decades, and the arrival of the new coronavirus provided vaccine manufacturers an opportunity to use this technology. Interest has grown in these vaccines because they can be developed in a laboratory, using readily available materials. This means the process can be standardized and scaled up, making vaccine development faster than traditional production methods.
The U.S. Centers for Disease Control and Prevention (CDC) says mRNA vaccines have been studied for flu, Zika, rabies and cytomegalovirus (CMV), a common virus found around the world.
As soon as the needed information about the virus that causes COVID-19 was available, scientists began designing the mRNA instructions for cells to build the proteins that cause the immune system to produce the antibodies needed to fight off future COVID-19 infection.
mRNA vaccines are held to the same rigorous safety and effectiveness standards as all other types of vaccines in the United States. The only COVID-19 vaccines the FDA will make available for use in the United States, by approval or emergency use authorization, are those that meet these standards.
Some people have wondered if the COVID-19 vaccine can make them sick with COVID-19 or interact with their DNA. The answer to both questions is, “No.”
The COVID-19 mRNA vaccines do not use the live virus that causes COVID-19. As a result, the vaccines cannot give someone COVID-19
Nor can the COVID-19 mRNA vaccines affect or interact with the body’s DNA in any way. mRNA never enters the nucleus of the cell, which is where DNA (genetic material) is kept. The cell breaks down and gets rid of the mRNA soon after it is finished using the instructions to make the protein.
The benefit of mRNA vaccines, like all vaccines, is that those vaccinated gain protection against future infection without ever having to risk the serious consequences of getting sick with the disease the vaccine is designed to protect against.
Sources: FDA, CDC