Laetitia Vancon—The New York Times/Redux

What has been called the Achilles heel of fighting the pandemic is that such a large proportion—an estimated 30% to 40%—of people with infections do not have symptoms but are fully capable of spreading COVID-19. Back in January, it was the astute observation of Dr. Camilla Rothe, an infectious-disease specialist in Munich, that led her team to be one of the first to document an asymptomatic infection. Her published report of symptomless spreading was first met with disbelief, denial and disparagement, but ultimately was confirmed in dozens of patient cohorts to be absolutely true and now is widely accepted.

Her discovery has saved countless lives, and if only we all had listened to Dr. Rothe earlier, more spread could have been prevented.

Topol, M.D., is a professor of molecular medicine at Scripps Research and the editor in chief of Medscape

More Must-Reads from TIME