How the COVID-19 mRNA Vaccines Work, and Some Current Concerns

Are There Concerns?

With any new technology come concerns, especially with ones like mRNA vaccines, which were developed rapidly and previously had never been delivered to millions of humans. Already, there are multiple myths circulating online and elsewhere, at least two of which relate to the function of mRNA vaccines.^6,7 One myth is that mRNA vaccines use a “live” version of the coronavirus. This is false. As described above, the mRNA for these vaccines was synthetically generated in laboratories; mRNA vaccines are not grown in eggs or cell cultures, though some other established vaccines in use for other diseases are. A second myth is that mRNA vaccines can alter the human cell’s DNA. As also noted previously, the synthetic mRNA remains in the cell’s cytoplasm until broken down and never enters the nucleus of the cell.

Several other hypothetical problems have been suggested. One of the chief hypothetical concerns is the possibility of the vaccine inducing an autoimmune state and/or heightened inflammatory state in the vaccinated host.⁷ Some have suggested that, by the human cell installing the virus spike protein on its cell membrane, certain immune systems could become hyperreactive and identify the whole cell as “foreign” and develop autoantibodies to all cells in its “lineage” all over the human body. This would in effect create a temporary or permanent autoimmune disease state. Others have proposed autoimmune reactions could occur if there are spike protein homologues elsewhere in the body.⁸ Autoimmune induction like this has previously occurred in medical therapies, most recently in some cases of cancer immunotherapy. However, many Pfizer clinical trial vaccine recipients are now over nine months out from their initial injections. So far, no reports have been released on any type of autoimmune or other ongoing or evolving debilitating symptoms related to vaccination.

As with any new medical technology, all of the answers we need will not be available until a very large number of people have received it. However, with the information available to us currently, a risk-benefit assessment strongly favors mRNA vaccination. This is especially true for those at increased risk of COVID-19 exposure or those at increased risk of developing more severe disease.

Dr. Severance is adjunct assistant professor in the department of medicine at Duke University School of Medicine in Durham, North Carolina, and attending physician in the division of hyperbaric medicine, department of emergency medicine at Erlanger Baroness Medical Center/Erlanger Health System and UT College of Medicine/UT Health Science Center in Chattanooga, Tennessee. Contact him via Linked in.