India’s official coronavirus death toll crossed the 400,000 mark, as the nation continued to grapple with the fallout of a devastating spring surge in cases, an outbreak that was driven in part by the more contagious delta variant now gaining ground in the United States and around the world. At least 400,312 people have died of the virus in India since the pandemic began, the government said Friday, out of more than 30 million confirmed infections. Experts believe both figures are vast undercounts, as record numbers of patients and deaths overwhelmed the country’s health-care system.

While the outbreak appears to have peaked in India — with 853 deaths recorded over the past 24 hours — the more virulent variant that spurred its spring wave is now seeding new virus clusters from Moscow to Jakarta to rural Missouri.

Here are some significant developments:

  • The Seychelles, one of the world’s most vaccinated nations, said that six fully inoculated people have died of the virus. Five had received an Indian-made version of the Oxford-AstraZeneca shot, while one was administered Sinopharm shots.
  • Indonesia recorded a record number of cases (24,836) and deaths (504) on Thursday. Local leaders warned that hospital capacity was under severe stress. The country has now placed two highly populous areas under lockdown.
  • Portugal reimposed a nighttime curfew on several “high-risk” cities including Lisbon and Porto. The country reported over 2,400 new cases on Thursday, many of which were unvaccinated young people.
  • Facing outbreaks of the contagious delta variant and a floundering vaccination campaign, Australia moved Friday to further seal itself off from the world as its earlier success in tackling the coronavirus continued to unravel.
  • South Korea reported 826 new infections on Friday — its highest daily caseload in almost half a year. After an exponential increase in vaccinations through mid-June, the pace has started slowing. Seoul recently relaxed a mask mandate for partially inoculated people.

The delta variant, first detected in India, has caused steep spikes in new cases even in nations with high vaccination rates such as Britain and Israel, which on Thursday recorded its highest daily infection rate in three months, the Associated Press reported. Officials in both countries, however, have credited the vaccines for weakening the link between infections and deaths.

Johnson & Johnson said Thursday that its one-shot coronavirus vaccine showed effective protection against the delta variant in a small study, offering hope to many developing countries now facing summer outbreaks. Studies suggest that all three U.S.-approved vaccines work well against the delta variant.

In the United States, delta is on track to eclipse other variants and become dominant in the coming weeks, Rochelle Walensky, director of the Centers for Disease Control and Prevention, said in a Thursday briefing. She said the delta variant now accounts for nearly 50 percent of new infections in some parts of the country, including “vulnerable” regions where inoculation rates are low.