More transmissible and possibly capable of reinfecting people who have recovered from the disease covid-19, the variant began devastating the Amazonian city of Manaus in early January, then stormed south. Late last week, the research institution Fiocruz announced that “variants of concern” including P.1 have become dominant in six of eight states studied…

Scientists across Brazil expressed deep pessimism for the coming weeks. The ICU occupation rate is at least 80 percent in most states, much higher in some. Patients are being transferred from state to state — sometimes traveling hundreds of miles — in a nationwide hunt for hospital resources. Without ventilators, nurses have pumped infected patients’ lungs manually. Cemeteries are running out of space to put the bodies. Refrigerated containers wait outside hospitals to take the overflow. People all over the country are dying at home, unable to get treatment.

The situation is unpredictable for both Brazil and the world. As viruses course through a population, they inevitably mutate. Most genetic changes are functionally insignificant. The coronavirus pandemic, which has infected more than 117 million people worldwide, has produced countless variants.

But uncontrolled outbreaks in communities with mounting immunity, scientists say, can give rise to more dangerous variants. It’s not by coincidence that one of the world’s most virulent variants emerged in Manaus, one of the world’s hardest-hit cities.