We’re covering Haiti rocked by the assassination of President Jovenel Mo？se, and signs of trouble ahead for Didi, the Chinese ride-hailing app.

       Haiti’s president is assassinated President Jovenel Mo？se of Haiti was assassinated in an attack in the early hours of Wednesday at his home on the outskirts of Port-au-Prince, the prime minister said, and his wife was shot as well. Here are the latest updates.

       There was little solid information about who might have carried out the assassination, and points of entry to Haiti were shuttered as the authorities tried to hunt down the assailants. As millions of Haitians wondered what was to come, there was a sense that the crisis would deepen the turmoil of the past few months. Claude Joseph, the interim prime minister, said that he was running the country at the moment.

       In recent months, the streets of Haiti have become filled with protests demanding the removal of Mo？se. He had clung to power, ruling by decree for more than a year, with constitutional scholars contending that his term had expired.

       On the ground: Armed gangs control the streets and have taken to kidnapping even schoolchildren and church pastors. Poverty is on the rise. Experts warn the political vacuum could lead to violence.

       Background: Mo？se had been pursuing a controversial rewrite of the Constitution. New changes would have granted him immunity for any actions and abolished the Senate, leaving a single legislative body.

       Vaccines are effective against variants Researchers have been tracking how well vaccines protect against the Delta variant of the coronavirus as it spreads. All the studies so far agree that most Covid-19 vaccines are very effective at keeping people out of the hospital and have generally protected against the Delta variant.

       Though the numbers vary from country to country, experts say that’s to be expected, because it’s hard for a single study to accurately pinpoint the effectiveness of a vaccine in real world conditions.

       Quotable: “Their overall implications are consistent: that protection against severe disease remains very high,” said one professor at the Johns Hopkins Bloomberg School of Public Health.

       The numbers: In Britain, two doses of the Pfizer shot had an effectiveness of 88 percent protecting against symptomatic disease from Delta. A June study from Scotland concluded that the vaccine was 79 percent effective against the variant. On Saturday, a team of researchers in Canada pegged its effectiveness at 87 percent.

       Here are the latest updates and maps of the pandemic.

       In other developments:

       Prime Minister Narendra Modi of India ousted 12 senior Cabinet members and inducted a new young team, hoping to improve the government’s image after criticism of its response to the Covid-19 crisis, Reuters reports.

       Hospitals are full in Fiji as it battles one of the fastest-growing Covid-19 outbreaks in the world.

       Didi may face more regulatory troubles On Wednesday, after Beijing already told the ride-hailing platform to stop signing up new users and opened a data security review, China’s internet regulator fined Didi and other tech companies — including Alibaba — for failing to report merger deals in advance.

       China’s antitrust authority has been scrutinizing the country’s internet industry with never-before-seen vigor. That means the company, its investors and its underwriters could be in for even more unpleasant surprises.

       Our reporters looked at the signs that Didi could face additional scrutiny in China, where it has tussled for years with city officials over permits and licenses, and even in the U.S. as it tries to tighten rules for foreign companies listed on stock exchanges. Shares of Didi lost a fifth of their value on Tuesday and fell again in early trading in New York on Wednesday.

       Quotable: “Even if the stock rebounds, American investors still have no insight into the company’s financial strength because the Chinese Communist Party blocks U.S. regulators from reviewing the books,” Senator Marco Rubio of Florida said.

       THE LATEST NEWS Asia News

       The Taliban attacked the provincial capital of Qala-e-Naw on Wednesday, freeing prisoners and appearing poised to overrun the city.

       Russian hackers are accused of breaching a contractor for the Republican National Committee last week, around the same time that Russian cybercriminals launched the single largest global ransomware attack on record.

       President Rodrigo Duterte of the Philippines said he was “seriously thinking” about running for vice president, a role that would allow him to keep serving after his term limit as president, Reuters reports.

       China’s WeChat app is tightening control over gay and lesbian content and deleting Chinese student accounts on L.G.B.T.Q. topics.

       Around the World

       Protests against the increasingly autocratic rule of President Mahmoud Abbas, and the death of an activist in the custody of the Palestinian Authority, have been harshly suppressed.

       Italy beat Spain to reach the final of the Euro 2020 soccer tournament. England plays Denmark for the other spot.

       The sprinter Sha’Carri Richardson, who failed a drug test for marijuana, will miss the Tokyo Olympics after officials did not choose her for the U.S. relay team.

       Former President Trump sued Facebook, Twitter and Google on Wednesday after the platforms took various steps to ban him or block him from posting.

       North America saw its hottest June on record. Europe didn’t fare much better, with its second-warmest June after 2019.

       Novak Djokovic beat Martón Fucsovics in the Wimbledon quarterfinals, and Roger Federer lost his match to Hubert Hurkacz.

       A Morning Read

       As U.S. troops pull out of Afghanistan, we talked to Vietnamese veterans of the Vietnam War who know what it’s like when the troops suddenly leave with little support left behind. “We wanted to fight, but no supplies, no fuel, no rockets. And the Americans did not help like they said they would,” one vet remembered of the fall of the Republic of Vietnam in 1975. “I think in the end we felt betrayed.”

       Lives lived: Dilip Kumar, the iconic Bollywood actor hailed as the “Tragedy King,” died Wednesday in Mumbai after a prolonged illness.

       ARTS AND IDEAS Do we really need 10,000 steps every day? A clock maker, hoping to capitalize on interest in fitness after the 1964 Tokyo Olympic Games, mass-produced a pedometer with a name that, when written in Japanese characters, resembled a walking man. It also translated as “10,000-steps meter,” creating an aim that became embedded in our global consciousness — and fitness trackers.

       But today’s best science suggests we do not need to take 10,000 steps a day, which is about eight kilometers, for the sake of our health or longevity. A happy median seems to lie between that arbitrary goal and the average in many Western nations, which is fewer than 5,000.

       A 2019 study found that women in their 70s who managed as few as 4,400 steps a day reduced their risk of premature death by about 40 percent, compared with women completing 2,700 or fewer steps a day. Benefits plateaued at about 7,500 daily steps.

       Another, more expansive study last year found that people who walked for about 8,000 steps a day were half as likely to die prematurely as those who accumulated 4,000. The statistical benefits of additional steps were slight.

       It’s good news — not least because other research shows that even the few who dutifully work up to the fabled 10k tend to backslide to their baseline.

       PLAY, WATCH, EAT What to Cook

       Muhammara chicken sandwiches are enlivened by an earthy spread of roasted red peppers, walnuts and lemon.

       Virtual Travel

       See an annual pilgrimage to gather peyote in the Mexican desert.

       What to Listen To

       We’ve got five minutes that will make you fall in love with symphonies.

       Now Time to Play

       Here’s today’s Mini Crossword, and a clue: Vietnamese noodle soup (three letters).

       And here is today’s Spelling Bee.

       You can find all our puzzles here.

       That’s it for today’s briefing. See you next time. — Melina

       P.S. Kate Kelly, who covers Wall Street for the Business desk, will join the Washington bureau to cover lobbying, big money and the world of influence.

       The latest episode of “The Daily” is about a much-debated Alzheimer’s drug.

       Whet Moser wrote the Arts and Ideas. You can reach Melina and the team at briefing@nytimes.com.