The Delta coronavirus variant’s deadly surge through the U.S. is leveling off, another sign that the nation’s most recent wave has crested.
The seven-day average for daily reports of new Covid-19 deaths has hovered near 2,000 for more than a week, and on Thursday slipped below 1,900, according to data from Johns Hopkins University. That follows a roughly two-month climb in deaths as Delta swept particularly aggressively through the southern U.S., hammering states like Florida, Louisiana and Arkansas. Public-health authorities and researchers say severe illness and deaths have largely hit unvaccinated populations.
The surge has pushed northward, hitting states from Idaho and Montana to Maine. But a cool-down in places like Florida has helped slow the national numbers, epidemiologists say. Cases started leveling off nationally in early September, leading to declines, and death trends tend to trail case trends by several weeks.
Public-health researchers have chalked up the easing in the Delta surge to a range of factors. Spikes in hospitalizations and deaths may have encouraged some people to take more precautions, and Delta’s rapid spread may have boosted the ranks of people who now carry immune protection from infections and helped slow down the spread of the virus, researchers say.
Some states like Texas and Florida have also increasingly turned to monoclonal antibodies to treat infected people, because the treatments can help patients who get them early enough to potentially avoid hospitalization.
The U.S. logged about 84,500 additional Covid-19 deaths in August and September, more than four times the number of known Covid-19 deaths from the prior two months, Johns Hopkins data show.
“Given that by far the vast majority of severe illness and death is occurring in the unvaccinated, that this really is now a pandemic of the unvaccinated, most of the deaths that we have seen in this surge were entirely preventable,” said Robert Kim-Farley, a medical epidemiologist and professor at the UCLA Fielding School of Public Health.
The U.S.’s pandemic-long death count, about 698,000, recently eclipsed the estimated count of 675,000 deaths from the flu pandemic a century ago. The population of the U.S. today is roughly three times as large as it was then.
Since Aug. 1, Florida has represented close to one-fifth of all U.S. Covid-19 deaths, according to Jason Salemi, an epidemiologist and associate professor at the University of South Florida’s College of Public Health, who maintains a dashboard of Florida data. Until Aug. 1, the state had represented between 6% and 7% of U.S. Covid-19 deaths, he said. Florida represents about 6.5% of the U.S. population, U.S. census data show.
He believes that once data reporting has caught up and fully covered the Delta surge, it will show Florida deaths peaked in early September.
“Delta has burned through the population,” he said.
There are signs, at least, that vaccinations have helped tamp down the worst outcomes during the Delta surge, since many older people are vaccinated, and the risk of Covid-19 mortality rises with age. About 65% of the U.S. population eligible for shots is fully vaccinated now, but the rate tops 83% for people ages 65 and up, according to the Centers for Disease Control and Prevention.