Much of vaccine hesitancy is grounded in the supposition that one is better off relying on one’s “natural immunity.” This in turn supposes that there is some dichotomy or antithesis between “natural” and “artificial” immunization. In fact, vaccines operate by introducing an inert virus or protein into the bloodstream, so that the immune system can respond and learn to create antibodies. It is actually the immune system doing the “work” of immunization. The role of the vaccine is to introduce a harmless version of the pathogen, so that immunity can develop in this safe environment, and the immune system will be better prepared if the real thing comes. The alternatives would be to (1) hope that one is never exposed to the pathogen or (2) get exposed to the new pathogen and hope that the immune system can deal with it effectively on the first try. The choice is not between “artificial” or “natural” immunity, but between a prepared and unprepared immune system.
COVID-19 is now endemic, so it is a statistical near-certainty that everyone will be exposed to it at some point in their lives. Since it is a novel pathogen, our immune systems are not prepared for it with any specificity. For the unvaccinated, the risk of hospitalization and death varies greatly by age and existing health conditions. Even those who are not hospitalized, however, may suffer lasting “long COVID” effects. These include neurological disorders, respiratory damage, and increased risk of blood clots. Thus COVID-19 presents a substantial health risk to most unvaccinated adults.
You could say that you are willing to assume this substantial risk, or that, in your particular case (e.g., due to young age), the risk is objectively small. It makes no sense, however, to be sanguine about the risk associated with COVID exposure while at the same time being fearful of the risk associated with the vaccine, which does nothing but introduce an inert spike protein into the bloodstream, albeit indirectly. It makes no sense to be fearful of the inert spike protein while having no fear of exposure to the real thing. In fact, all the side effects of vaccines, including the serious effect of blood clotting, are effects associated with COVID-19. This only makes sense, because the inactive ingredients of the vaccine are harmless in their minute quantities, so whatever side effects result would be from the spike protein and the immune response to the same.
The mRNA vaccines (Pfizer and Moderna) work by introducing mRNA into muscle cells, instructing the body to create the spike protein. The mRNA itself, being quite fragile, disintegrates within a few days. The spike protein can remain for a few weeks, as the immune system takes time to develop a response. The Johnson & Johnson (Janssen) vaccine uses a piece of virus DNA (incapable of replicating) with instructions to create the spike protein. This adenovirus method has been in use since the 1970s. The mRNA method, though newly implemented, has been studied for decades. It has not been used previously not because it is unsafe (the mRNA does nothing but code for the inert protein), but because there has been no practical need. The difficulty and cost of storing mRNA is offset by the need to produce vaccines in unprecedented large quantities in a short time.
The COVID vaccines are different from most vaccines only in that they introduce the protein indirectly by genetic instructions, though even this is not truly novel, since DNA has long been used in adenovirus vaccines. Most vaccines operate by introducing the inert pathogen directly. They are not “medicines” or “artificial chemicals,” but pseudo-pathogens introduced to stimulate the immune system to prepare a defense. This is why the side effects of all vaccines are generally similar to the symptoms of the disease to be prevented.
The only lasting products of the COVID vaccines are the antibodies produced by the immune system. The mRNA/DNA disintegrates in days, and the spike protein is gone in a few weeks. These are all “natural” substances that operate according to well-understood biochemistry that regularly occurs in the body.
There is some evidence from Israel suggesting that the immunity (measured in antibody levels) resulting from exposure to COVID in the unvaccinated is greater than that provided by vaccination. Even if this is true, it is not a worthy comparison, for this ignores the substantial health risk involved in being exposed to COVID while unvaccinated. The greater immunity achieved is only subsequent to going through COVID, and it is not possible to know in advance if one will get a severe case or long-term symptoms. It would not be surprising if exposure to the real thing indeed provides better immunity than exposure to a pseudo-pathogen, but this is achieved only after a failure to prevent the disease. The same Israeli study notes that immunity is further enhanced by vaccination following exposure. This finding shows that “natural” and “vaccine” immunity are not antithetical, but complementary.
Early claims about the efficacy of the mRNA vaccines proved to have been overstated, at least with regard to preventing infection. Some of this has to do with the more infectious delta variant, and some has to do with the degradation of immunity levels over time, becoming substantial at six months. A regimen of once or twice annual boosters seems likely. Nonetheless, the vaccines do remain highly effective at reducing severe cases and the long-term health effects associated with these. It would obviously be more prudent to obtain this immunity before one enters the high-risk age group.
In short, without getting into the propriety of legal mandates and the rights of the individual versus those of society, we can see a unilateral prudential benefit to vaccination, at least for adults. All of the risks associated with vaccines are objectively small, and even if they were not, they are necessarily no worse than the risk assumed by not being vaccinated, once it is understood that COVID is endemic and that the vaccines operate solely by introducing inert pathogens, letting the immune system do the work of developing a defense.
By now, practically all of us know someone who has had COVID, perhaps including an unvaccinated person with a severe case and an elderly vaccinated person with a mild case. Some of us may have noted how immunity to infections drops after six months, and those with boosters fare better when exposed in large unmasked gatherings. We cannot reasonably pretend that the health risk is negligible, nor that outcomes are not materially affected by vaccination. Hopefully, a demystified understanding of the quite ordinary processes by which vaccines operate will help remove hesitancy in more people.