Some would say coronaviruses are our mortal enemy. After all, tens of millions of Americans have contracted COVID-19 and hundreds of thousands have died. Similarly, tens of millions have lost their jobs and hundreds of thousands of businesses have closed. One estimate puts the total cost of the pandemic at $16 trillion, roughly equal to the nation’s total annual economic output.
We have declared war on such foes in the past. President Lyndon Johnson did so on poverty in 1964, President Nixon did the same for cancer in 1971, and Federal Reserve Chair Paul Volcker declared war on inflation in 1979. In doing so, they implied that such scourges could be vanquished, recalling U.S. victories in the world wars.
In some cases, we have in fact achieved what looks like total victory over infectious diseases. For example, smallpox once killed about 30 percent of the people it infected, a far higher rate than the 1-2 percent fatality rate of COVID-19. Centuries ago, smallpox decimated civilizations such as the Aztecs. Yet thanks to a worldwide vaccination program, the World Health Organization declared the disease eradicated in 1980.
It is unlikely that we could achieve a similar feat with the coronavirus. For one thing, SARS-CoV-2, the virus that causes COVID-19, belongs to but one of at least four genuses of coronavirus, which contain dozens of species. Coronaviruses infect many wild species, such as birds, bats, and pigs, as well as domesticated dogs and cats. Smallpox virus, by contrast, naturally infects only humans.
In fact, coronaviruses have been infecting human beings for thousands of years, at least. Four types of the virus produce generally mild disease resembling the common cold. It is only in the last 20 years that more dangerous human coronavirus infections have been identified, including MERS-CoV2 and the first SARS-CoV.
Even as we struggle with the daily fear, sadness, loneliness, and exhaustion that COVID-19 has wrought, it is important for us to try to view the situation with a wide lens and, as much as we are able, take the long view. It is quite possible, perhaps even probable, that the relatively harmless forms of human coronavirus infection were once more deadly.
While it doesn’t mean we should do nothing—we need to keep mask mandates in place, and continue to socially distance, and get vaccines into arms as quickly as possible—the problem with declaring war on COVID-19 is that coronaviruses are impossible to vanquish. They are too numerous, too widespread across the animal kingdom, and too protean. With time, we may design better anti-viral drugs or develop herd immunity through growing numbers of natural infections and vaccinations. Yet even when COVID-19 fades, coronaviruses are here to stay.
And viruses are not entirely bad actors. For example, they have been major drivers of evolution. Viruses can transmit genetic material from one organism to another, and they induce changes in the functions of cells seeking to resist infection. We would not be here without them. Quite recently, researchers have engineered viruses that can kill different types of cancer cells.
The same can be said for other types of infectious microbes, such as fungi and bacteria. Without fungi, human beings could not make bread and wine. And while some bacteria cause dreaded diseases such as bubonic plague, others are vital to health. Vitamin K, which is essential for normal blood clotting, is synthesized by normal intestinal bacteria.
It is not just that individual fungi and bacteria are good. We need a whole array of such organisms to remain healthy. Medications such as antibiotics, which are used to treat harmful infections, can end up killing many forms of good bacteria too, with the result that the skin, the respiratory tract, or the gut is left open for colonization by bad actors.
Biomedically speaking, the good neighbors among our microbial flora keep the bad neighbors at bay. This is one reason that the overuse of antibiotics and the routine use of antibacterial soaps cause more harm than good. In patients who have developed life-threatening C. difficile infections after antibiotic treatment, fecal transplants have been introduced as means of restoring bacterial balance.
In short, a war on viruses, fungi, and bacteria would prove unwinnable, and many apparent victories might turn out to inflict as much harm on the victors as the vanquished. Some of these harms are foreseeable, but we still have a great deal to learn about the complex and delicate balances between microbes and human beings.
Instead of picturing human beings in white hats and microbes in black hats, we need to think of ourselves as neighbors in the same biological neighborhood. Warfare and eradication are self-defeating metaphors that need to be replaced by visions of a better informed and prepared but ultimately more peaceful coexistence.
Richard Gunderman, MD, Ph.D., Chancellor’s Professor of Radiology, Pediatrics, Medical Education, Philosophy, Liberal Arts, Philanthropy, and Medical Humanities and Health Studies at Indiana University, is the author of Contagion: Plagues, Pandemics and Cures from the Black Death to Covid-19 and Beyond.