Many patients being hospitalized have underlying health conditions like diabetes, obesity or high blood pressure that are risk factors for severe disease, he said. But some younger patients have none of those risk factors.
“That’s what really frightens me,” he said. “It’s hitting younger healthy people that you wouldn’t think would have such a bad response to the disease.” They often face prolonged recoveries, Dr. Coulter added, and some will have lasting lung damage.
In the United States, the Delta variant is a relatively new arrival, and evidence on whether and how it behaves differently is still accumulating. It is more contagious, experts agree. People who are infected may carry the variant in high amounts in their airways, a few studies have found.
The variant may also cause more severe disease, some researchers have suggested. A study in Scotland, which was published in The Lancet, examined Covid cases in the spring, when Delta became the dominant strain in that country.
Patients infected with the variant were at nearly twice the risk of being hospitalized, compared with those infected with the earlier Alpha variant. The patients also were younger, presumably because they were last in line to be vaccinated, the authors said.
In a preliminary study posted online and not yet peer-reviewed, Canadian researchers found the risk of being admitted to intensive care was nearly four times as high in patients with the Delta variant, compared with patients infected with other variants. Patients with the Delta variant were at twice the risk of hospitalization or death.
Research in Singapore, which is to be published in The Lancet, concluded that patients with the Delta variant faced higher odds of requiring oxygen, needing intensive care, or dying. And a study in India, which was also posted online and not yet peer-reviewed, found that in the second wave of infection, when the Delta variant was dominant, patients faced a greater risk of dying, especially those under the age of 45.