One of the problems I see in today’s post-truth era, exacerbated by the double-edged sword of internet and social media, is widespread misinformation (possibly unintentional falsehoods) and disinformation (intentional falsehoods).
I believe this is why many people are either hesitant to take covid vaccines, skeptical that they are effective, or fear that they are part of a conspiracy.
My purpose in this essay is to allay those concerns by presenting a lay-person’s explanation of how a coronavirus vaccine works.
You could rightly ask “what qualifies a mechanical engineer to instruct on such a matter?” The answer is: Both my daughter and her husband have doctorates in cell biology, and from them I can often extract details limited only by time and my ever-diminishing capacity to assimilate.
There are several types of coronavirus vaccines presently in use, but since the end result is the same for all, I will address only the type called “mRNA vaccine” which is created and supplied by Moderna and Pfizer-BioNTech.
mRNA is short for messenger ribonucleic acid. Its normal everyday function is to read your DNA, the recipe for building and maintaining your body that resides in almost every cell, and transfer that information to your protein-building machinery called transfer RNA and ribosomes. Proteins are large molecules in thousands of types, each a long chain of much smaller molecules called amino acids, folded up into a variety of compact shapes. Together, proteins comprise the second largest percentage of your body weight, water being the largest.
A virus such as the SARS-cov-2 coronavirus is a parasitic organism that lives and reproduces by attaching itself to a normal healthy cell. By itself the virus can live only a few days. It attaches to a host cell by means of its “spike proteins”, those little cone-shaped thingees that protrude from the outer surface of its body. Without those spikes the virus cannot survive.
mRNA vaccines contain synthetically-manufactured mRNA molecules that instruct your cells to start making the same spike proteins that cover the virus. Those spike proteins circulate in your bloodstream and, while not harmful by themselves, are recognized by your immune system as foreign material “not belonging to you”. Your immune system’s job is to search out and destroy particles in your body that are not supposed to be there. It does this by using its white blood cells to produce antibodies which attack and destroy unwanted, harmful materials, in this case the spike proteins just created by introduction of the vaccine.
Are you old enough to remember the early computer game called “Pac-man”? In this game you used a joystick to guide your little yellow guy through a maze, eating lines of dots while trying not to be caught by four ghosts chasing him. Think of your antibodies as Pac-men circulating through your bloodstream, searching for, and eating, undesirable particles.
The new antibodies destroy the mRNA-created spike proteins, and hang around for a while (a few months) just in case they may find more. Unfortunately for the virus, when it enters your body, these antibodies are poised to kill the spike proteins that cover it. The vaccine gives your immune system a head-start in defeating the virus. Without it, your immune system, especially if already compromised by fighting some other pathogen, could become overwhelmed by the virus before it could make enough antibodies to defeat it. In that case, sickness or death ensues.
The spike-eating antibodies gradually diminish in number. That’s why we need booster shots every six months or so if we want to stay protected. And we will need new formulations of the vaccine to handle new variants of covid and whatever else is coming for us.
I hope this information, available in more detail at Wikipedia.org, helps reduce anxiety and skepticism regarding the vaccines.
One last point. By getting vaccinated for covid and flu you benefit not only yourself but also your neighbors.
Bob Moores retired from Black & Decker/DeWalt in 1999 after 36 years. He was the Director of Cordless Product Development at the time. He holds a mechanical engineering degree from Johns Hopkins University.