Covid, in Retreat

Covid-19 is once again in retreat.

The reasons remain somewhat unclear, and there is no guarantee that the decline in caseloads will continue. But the turnaround is now large enough — and been going on long enough — to deserve attention.

The number of new daily cases in the U.S. has fallen 35 percent since Sept. 1:

Worldwide, cases have also dropped more than 30 percent since late August. “This is as good as the world has looked in many months,” Dr. Eric Topol of Scripps Research wrote last week.

These declines are consistent with a pattern that regular readers of this newsletter will recognize: Covid’s mysterious two-month cycle. Since the Covid virus began spreading in late 2019, cases have often surged for about two months — sometimes because of a variant, like Delta — and then declined for about two months.

Epidemiologists do not understand why. Many popular explanations, like seasonality or the ebbs and flows of social distancing, are clearly insufficient, if not wrong. The two-month cycle has occurred during different seasons of the year and occurred even when human behavior was not changing in obvious ways.

The most plausible explanations involve some combination of virus biology and social networks. Perhaps each virus variant is especially likely to infect some people but not others — and once many of the most vulnerable have been exposed, the virus recedes. And perhaps a variant needs about two months to circulate through an average-sized community.

Human behavior does play a role, with people often becoming more careful once caseloads begin to rise. But social distancing is not as important as public discussion of the virus often imagines. “We’ve ascribed far too much human authority over the virus,” as Michael Osterholm, an infectious-disease expert at the University of Minnesota, has told me.

The recent declines, for example, have occurred even as millions of American children have again crowded into school buildings.

Hospitalizations, too

Whatever the reasons, the two-month cycle keeps happening. It is visible in the global numbers, as you can see in the chart below. Cases rose from late February to late April, then fell until late June, rose again until late August and have been falling since.

The pattern has also been evident within countries, including India, Indonesia, Thailand, Britain, France and Spain. In each of them, the Delta variant led to a surge in cases lasting somewhere from one and a half to two and a half months.

In the U.S., the Delta surge started in several Southern states in June and began receding in those states in August. In much of the rest of the U.S., it began in July, and cases have begun falling the past few weeks. Even pediatric cases are falling, despite the lack of vaccine authorization for children under 12, as Jennifer Nuzzo of Johns Hopkins University told The Washington Post. (You can see the overall trends for every state here.)

The most encouraging news is that serious Covid illnesses are also declining. The number of Americans hospitalized with Covid has fallen about 25 percent since Sept. 1. Daily deaths — which typically change direction a few weeks after cases and hospitalizations — have fallen 10 percent since Sept. 20. It is the first sustained decline in deaths since the early summer.

‘The last major wave’?

This is the part of the newsletter where I need to emphasize that these declines may not persist. Covid’s two-month cycle is not some kind of iron law of science. There have been plenty of exceptions.

In Britain, for example, caseloads have seesawed over the past two months, rather than consistently fallen. In the U.S., the onset of cold weather and the increase in indoor activities — or some other unknown factor — could cause a rise in cases this fall. The course of the pandemic remains highly uncertain.

But this uncertainty also means that the near future could prove to be more encouraging than we expect. And there are some legitimate reasons for Covid optimism.

The share of Americans 12 and over who have received at least one vaccine shot has reached 76 percent, and the growing number of vaccine mandates — along with the likely authorization of the Pfizer vaccine for children ages 5 to 11 — will increase the number of vaccinations this fall. Almost as important, something like one-half of Americans have probably had the Covid virus already, giving them some natural immunity.

Eventually, immunity will become widespread enough that another wave as large and damaging as the Delta wave will not be possible. “Barring something unexpected,” Dr. Scott Gottlieb, a former F.D.A. commissioner and the author of “Uncontrolled Spread,” a new book on Covid, told me, “I’m of the opinion that this is the last major wave of infection.”

Covid has not only been one of the worst pandemics in modern times. It has been an unnecessarily terrible pandemic. Of the more than 700,000 Americans who have died from it, nearly 200,000 probably could have been saved if they had chosen to take a vaccine. That is a national tragedy.

Covid also isn’t going to disappear anytime soon. It will continue to circulate for years, many scientists believe. But the vaccines can transform Covid into a manageable disease, not so different from a flu or common cold. In the past few weeks, the country appears to have moved closer to that less grim future.

Whatever this autumn brings, the worst of the pandemic is almost certainly behind us.

Virus developments:

• The pandemic has made diapers more expensive and scarce.

• Johnson & Johnson is planning to ask for federal authorization for boosters this week.

THE LATEST NEWS

Politics

• Progressive Democrats said that they were open to compromising with moderate senators on Biden’s social and climate bill.

• It’s the first day of the Supreme Court’s term, which will include cases on abortion, gun rights and more.

Other Big Stories

• A pipeline failure near Orange County, Calif., caused an enormous ocean oil spill.

• A former Facebook product manager said that she was the whistle-blower behind a leak. She said the company “has shown it chooses profit over safety.”

• Clint Eastwood won a $6 million lawsuit against a Lithuanian company that used his image to promote CBD products.

• The Pandora Papers: The Washington Post and others reveal how the wealthy, including world leaders, hide billions from tax authorities. Among them: the king of Jordan.

• The Nobel Prize in Physiology or Medicine went to two U.S. researchers. Their work sheds light on how to reduce chronic and acute pain.

• Tom Brady became the N.F.L.’s career passing leader. He now has 80,560 career yards passing.

Opinions

“Sinema is a puzzle”: Maureen Dowd writes about the Sphinx-like Arizona senator.

Pessimistic liberals should remember their many victories over the past two decades, says Ross Douthat.

Gail Collins and Bret Stephens discuss Democrats’ disagreements over Biden’s agenda.

MORNING READS

Bricks: Developers wanted to build a Legoland theme park. It tore a small town apart.

The Media Equation: What did investors see in Ozy Media?

Saildrone: This is what it looks like inside a Category 4 hurricane.

Quiz time: The score on our most recent News Quiz was 9.6. Can you beat it?

Advice from Wirecutter: Tips for better laundry.

Lives Lived: Marcia Freedman was the first and only open lesbian — and first American-born woman — to serve in the Knesset, Israel’s Parliament. She died at 83.

ARTS AND IDEAS

The Beatles in the classroom

Would you get a master’s degree in the Beatles? In the band’s hometown, a postgraduate program aims to turn fans into students of the Fab Four’s legacy by studying their sociological, historical and economic impact.

As a new semester began last week at the University of Liverpool, 11 eager students, ages 21 to 67, trooped into class to start the program. One wore a Yoko Ono T-shirt, Alex Marshall reports in The Times, while another had a yellow submarine tattooed on his arm. Two had named their sons Jude, after one of the band’s most famous songs.

Academics have studied the Beatles for decades, and the program is the latest example of that. The Beatles are big business locally as well: Liverpool’s association with the band was worth over $110 million a year, a 2014 study found. Tourists visit sites named in the band’s songs and venues where the group played.

Two professional tour guides in the course said they hoped the program would help them attract customers. “The tour industry in Liverpool is fierce,” one said.

Another student, Alexandra Mason, recently completed a law degree but decided to change track when she heard about the Beatles course. “I never really wanted to be a lawyer,” she said. “In my mind, I’ve gone from the ridiculous to the sublime.” — Sanam Yar, a Morning writer

PLAY, WATCH, EAT

What to Cook

It’s not a 30-minute meal, but this lasagna is worth the effort.

What to Read

Stanley Tucci’s passion was acting. Now, it’s food.

What to Watch

Are you watching “Squid Game”? The dark Korean drama, where desperate characters play lethal children’s games for money, is on track to become Netflix’s most popular original series ever, Vulture reports.

Late Night

“Saturday Night Live” returned, with a new cast member playing Biden.

Now Time to Play

The pangram from Friday’s Spelling Bee was juvenile. Here is today’s puzzle — or you can play online.

Here’s today’s Mini Crossword, and a clue: School tests (five letters).

If you’re in the mood to play more, find all our games here.

Thanks for spending part of your morning with The Times. See you tomorrow. — David

P.S. Colby College gave its courage in journalism award to eight journalists, including from The Times, whose phone records were secretly seized by the Justice Department.

Here’s today’s print front page.

“The Daily” is about ivermectin. On the Book Review podcast, Richard Powers and Honorée Fanonne Jeffers talk about their novels. “Sway” features Monica Lewinsky.

Claire Moses, Ian Prasad Philbrick, Tom Wright-Piersanti, Ashley Wu and Sanam Yar contributed to The Morning. You can reach the team at [email protected].

Sign up here to get this newsletter in your inbox.