Covid cases dip below 100,000 a day in U.S. as nation faces colder weather and more closed-in spaces

Average daily Covid cases in the U.S. fell below 100,000 Thursday as the pandemic shows further signs of easing with more than 56% of the population fully immunized against the virus — a starkly different trend than the record-setting surge the country was heading toward last fall.

Armed with vaccines this fall, cases have been steadily declining since the country’s most recent peak of about 172,500 average daily infections on Sept. 13, according to data compiled by Johns Hopkins University. It’s the first time daily cases have dropped below 100,000 since early August, the data shows, but health experts are urging caution despite the positive signs they see in the numbers.

“I think right now, it looks like we’re in for a relatively tough fall with sustained transmission of Covid in our communities,” said Dr. Barbara Taylor, an assistant dean and professor of infectious diseases at the University of Texas Health Science Center at San Antonio. She said the still-high infection rates means the country is not yet out of the woods, though she said it was encouraging that cases weren’t surging again. “But I’m hesitant to say that we know everything about what it’s going to look like.”

While infections this time last year were less than half today’s levels, they were quickly rising and eventually reached a pandemic peak after the holiday season of more than 250,000 per day on Jan. 11. The death toll followed suit, eventually topping out at about 3,400 per day in early 2021. 

Along with the fall in cases, there are encouraging signs in U.S. hospitalizations and fatalities. About 69,000 Americans are currently in the hospital with Covid, according to the Department of Health and Human Services, down from nearly 104,000 on Sept. 1. The average daily death toll currently sits at about 1,680 over the last week, down 18% from its recent high point of roughly 2,050 per day on Sept. 22.

While the decline in deaths is reassuring, the daily number of U.S. fatalities is still “substantial and tragic,” said Dr. Jeremy Faust, an emergency physician at Brigham and Women’s Hospital.

“We’ve become so numb to the numbers that even something like 500 deaths per day this coming winter might be packaged by some as some kind of victory just because it’s not 3,000 or more. How sad is that?” said Faust, who’s also an instructor at Harvard Medical School.

Cases, deaths, and hospitalizations are all currently higher than they were both one year ago and earlier in the summer before the delta variant took hold across the country. Average case counts were as low as 11,400 per day as recently as June.

The major difference in 2021, of course, is the emergence of Covid vaccines. Almost two-thirds of the U.S. population has received at least one vaccine dose and 56.2% is fully vaccinated, according to the Centers for Disease Control and Prevention.

“You can’t ignore the tremendous individual and population-level protection that the vaccines have afforded the United States,” said Dr. Isaac Bogoch, an infectious disease physician and professor at the University of Toronto.

Still, the latest outbreak driven by the highly contagious delta variant has surged even as U.S. officials vaccinated 216 million Americans with at least one vaccine dose over the last ten months. U.S. officials have repeatedly said that the vast majority of those currently hospitalized and dying because of Covid are unvaccinated. Plunging temperatures through the fall and winter could further increase the risk as people start gathering in poorly ventilated areas where Covid can rapidly spread, experts say.

“It gets cold, everybody goes indoors, we close windows, we have less air circulation, we have to be in places that are heated, and that is going to increase transmission under any circumstance,” Taylor said.

Challenges remain in some parts of the country. With steep declines in infections in southern states like Florida, Louisiana, and Texas, the Midwest is now the region with the highest rate of average daily new cases per capita.

Illinois, Michigan, Minnesota, and Wisconsin make up four of the eight states in which case counts have increased by 5% or more over the past week. 

Falling cases in the south are contributing heavily to the overall U.S. downward trend, according to former Food and Drug Administration commissioner Dr. Scott Gottlieb, who said that delta may still be working its way through some parts of the country.

“The situation looks like it’s getting better across the country because it’s being driven by sharp declines in cases in the south, but the situation in the west and the midwest right now is very difficult,” Gottlieb, who sits on Pfizer’s board of directors, said on CNBC’s “Squawk on the Street” on Wednesday. 

In the Northeast, where population-adjusted rates of new cases have been lowest throughout the delta surge, Gottlieb said he expects to see a pickup in cases but nothing near what the South or Midwest have experienced.

Other health experts agreed. How the pandemic in the U.S. looks over the next few months will depend largely on how Americans behave heading into the holiday season. Getting vaccinated, receiving booster shots and avoiding large gatherings are crucial ways to mitigate against breakthrough cases and holiday outbreaks, said Dr. Bruce Farber, chief of infectious disease at Northwell Health in New York.

“Unvaccinated people should never be invited to a party,” Farber said.

They urged that Americans practice “common sense,” saying people should still wear masks and social distance when indoors or in a crowded setting, and especially around the elderly or those with weakened immune systems.

“When you’ve got tens and tens of millions of people that remain unvaccinated, it’s hard to be confident that the worst is behind you,” infectious disease expert Bogoch said.

Disclosure: Scott Gottlieb is a CNBC contributor and is a member of the boards of Pfizer, genetic testing start-up Tempus, health-care tech company Aetion and biotech company Illumina. He also serves as co-chair of Norwegian Cruise Line Holdings’ and Royal Caribbean’s “Healthy Sail Panel.”