The coronavirus had already killed Nieves Salas Solis’ mother and brother when he called his daughter from a hospital bed with a chilling message: “I’m next.”

Nieves, 62, who grew up in Dallas and in recent years lived in a Mexican border town doing community outreach, had a high fever and shortness of breath. It was mid-August, and he had managed to drive himself to a hospital in Harlingen, Texas, where doctors confirmed that he had Covid-19. But their efforts to clear his lungs were not working, said his daughter, Ana Alonso.

Ana knew her father was grieving his mother, Eva Solis-Salas, 89, who died Aug. 6, and a brother, Ruperto Salas Solis, 67, who died Aug. 10, after their own brief battles with the coronavirus.

But the thought of losing him, too, was unimaginable. Nieves was a “health freak” who ran