Why Are We Still Arguing About Masks?

In the past few weeks, the conventional wisdom about COVID seems to have been upended.

Early in the pandemic, several mainstream news outlets dismissed theories that COVID came from a Chinese lab. But recently The Wall Street Journal and The New York Times reported that the Department of Energy reversed its prior judgment by announcing that the coronavirus probably did emerge from a laboratory. The FBI shares that assessment.

What’s more, for the past three years, many scientists and writers—including me!—have reported that masks are effective at reducing the transmission of COVID. But last month, the...