The fall in virus cases: A 35 percent decline
A mass vaccination drive at Dodger Stadium in Los Angeles.Ryan Young for The New York Times
Virus cases are falling more sharply in the U.S. than at any previous point.
The United States has never experienced a sharp and sustained decline in new coronavirus cases — until, perhaps, now.
Last year, new cases in the U.S. went through cycles of rising rapidly and then leveling off or falling only modestly. That was different from the situation in many other countries, where sharp drops sometimes occurred. Look at how much bigger the declines were in Western Europe last spring and last fall than in the U.S.:
By The New York Times | Sources: Governments and health agencies
But now the situation may be changing.
New cases in the U.S. have fallen 35 percent over the past three weeks. Hospitalizations have dropped, as well. Deaths have not, but they have stabilized — and the death trend typically lags the cases trend by a few weeks.
“I like the trends we are seeing, and I am personally hopeful that things are going to get better. But there are a number of things that could also wrong.”
Jennifer Nuzzo, an epidemiologist at Johns Hopkins University, told me.
The good news
Let’s start with two possible explanations for the recent improvement:
1. We may be in the very early stages of herd immunity. Roughly 100 million Americans seem to have had the virus. (For every person who tests positive, three more have had it without being diagnosed, studies suggest.) Another 24 million people have received a vaccine shot.
Put those two groups together, and you realize that about one-third of all Americans have at least some degree of immunity from the virus. That may be enough to begin — begin — slowing the spread, as my colleague Donald G. McNeil Jr. explained on “The Daily.”
2. More Americans may be wearing masks and staying socially distant. Many still are not, as I saw on my recent 1,600-mile road trip. But any increase in safe behavior matters.
And there are signs of change. Multiple states tightened restrictions late last year. The country just elected a president who echoes scientific advice rather than flouting it. Some Americans may also be inspired by light at the end of the tunnel.
“I’m hearing from a lot of people that one of the reasons why they’re really hunkering down now is that it would be a shame to get a severe Covid case while waiting to get the vaccine,''
Dr. Lee Harrison, the chairman of a local health board, told The Pittsburgh Post-Gazette this week.
“Folks are changing behavior. Folks are wearing masks, folks are staying home, and that is resulting in these decreasing cases.”
Dr. Mark Escott, who runs the a local health agency around Austin, Texas, told the CBS affiliate there.
“The fact that this is happening in the winter when respiratory viruses typically spread the most shows us just how effective all the preventative measures actually are when we use them.”
Dr. Alex Garza, a member of a pandemic task force in St. Louis, told The Associated Press.
It could get worse again
I want to emphasize that the pandemic has not entered an inexorable decline.
The biggest reason for concern is the newly infectious variants that could cause case numbers to surge again, especially if people become blasé about masks and distancing — or the Biden administration fails to accelerate vaccinations. And the current rate of death from Covid-19 remains horrific.
But the U.S. has it within its power to make this month a true turning point.