This is the editor’s letter in the current issue of The Week magazine.

Two years after COVID began spreading through humanity, we are still adapting to SARS-CoV-2, and it is still adapting to us. It’s a Darwinian struggle, fought on the battlefield of natural selection, with immunity conferred by vaccination and infection competing against the random mutations that enable the coronavirus to shape-shift, become fitter, and launch new waves of attack. Will the Omicron wave — now starting to subside on the East Coast, as it previously did in South Africa and the U.K. — be the last big one, with COVID soon becoming a milder disease we can live with? Scientists have varying opinions — but the truth is, no one knows. There are so many variables involved: vaccination and booster rates, human behavior (do people abandon all precautions too quickly?), and whether a new variant emerges that’s even more effective than Omicron in evading built-up immunity.

Understandably, many people have embraced the comforting belief that SARS-CoV-2 must evolve to cause milder disease. It’s just not true, virologists say. Smallpox did not grow milder over time, nor did polio, HIV/AIDS, or Ebola. Only vaccination, antiviral treatments, and precautions to limit transmission enabled humanity to mitigate or defeat those scourges. Our own actions will largely determine what happens from here. Letting the virus rip only increases the likelihood of nastier mutations, and may prolong rather than end the pandemic. “COVID-19 becoming a milder disease is not a decision the virus will make,” said virologist Dr. Andrew Pekosz. “It’s a decision that all of us can make if we take advantage of the vaccines that can control spread.” There’s reason for optimism: Pfizer’s potent antiviral treatment, Paxlovid, will become more widely available in months, and several groups of scientists are working on a pan-coronavirus vaccine providing immunity against all variants. But if we’ve learned anything during these two ghastly years, it’s that magical thinking will not make our viral foe disappear.