India saw the world’s biggest one-day jump in coronavirus cases ever as a ferocious new wave grips the country, overwhelming hospitals and crematoriums and prompting frantic cries for help on social media.

The South Asian nation reported 314,835 new infections Thursday, topping a peak of 314,312 recorded in the U.S. on Dec. 21. People took to Twitter and Instagram to call for everything from hospital beds to medicine and doorstep COVID-19 tests.

The grim milestone shows how the pandemic crisis has shifted firmly to the developing world, where variants and complacency are threatening containment measures and there’s a lack of vaccines, with supplies dominated by richer nations.

India now has almost 16 million cases, the second-most globally, as it struggles to provide enough shots for its 1.3 billion people despite being home to the world’s biggest vaccine manufacturer. Lower vigilance around masks and social distancing have contributed to the resurgence, with large religious festivals and elections allowed to take place with few precautions.

It stands in contrast to America, where cases are on a downward trend, helped in part by aggressive vaccinations. Even at the height of its outbreak, the U.S. only reported more than 300,000 cases on two days.

India’s second wave is also more lethal after the country saw fewer fatalities than other developing nations earlier in the pandemic, puzzling experts. COVID-related deaths have jumped to more than 184,000, still trailing the U.S., Brazil and Mexico, according to Johns Hopkins data.

A health worker at a makeshift COVID-19 quarantine facility in New Delhi, on April 21.

On Bharath Pottekkat’s Instagram feed, one message screams “Mumbai please help! Lungs damaged due to pneumonia infection. In need of ICU bed.” Another reads “Plasma urgently required for treatment of COVID patient in Max Hospital, Delhi.” More follow. “Urgently needed Tocilizumab injection. Please DM if you know of stock in and around Mumbai.”

The relatively slow pace of vaccinations is adding to the problem. India has administered more than 132 million vaccine doses, according to data from its health ministry. That’s enough to cover only about 4.8 per cent of its population, according to Bloomberg’s vaccine tracker.

The outbreak threatens to derail the Indian economy, which had just begun to recover after a nationwide lockdown last year pushed it into a historic recession. A new virus variant with a double mutation has also been detected locally, and concerns are growing that it’s driving the new wave.

New Delhi’s largest hospital chain operator rushed to court Wednesday night to seek critical oxygen supply after 1,400 COVID-19 patients across the Indian capital were put at risk due to “dangerously low” supply levels.

The Delhi High Court’s two-judge panel headed by Justic Vipin Sanghi expressed “shock and dismay” over the government’s neglect and directed Prime Minister Narendra Modi’s administration to “beg, borrow, steal” but ensure adequate oxygen supply for hospitals.

“This is just bad planning. Why didn’t we foresee this? This is not rocket science,” Justice Sanghi said during the hearing.

The late-night courtroom drama, with the state and federal government lawyers bickering over oxygen supplies to the national capital, which has among the best health-care infrastructure in the country, is a grim indicator of a worse situation in the hinterlands.

The ferocity of the second wave is also resonating with investors and analysts. Indian stocks and the rupee have turned Asia’s worst performers this month as sentiment soured, while credit default swaps also surged. Care Ratings Ltd. on Wednesday lowered India’s gross domestic product growth forecast for the current fiscal year to 10.2 per cent, from as much as 11.2 per cent last month. This is its second downward revision in less than a month.

The outbreak is also prompting responses from other countries.

Singapore on Thursday announced a ban on visitors from India. Australia will cut flights from India to reduce COVID risk, Indian news channel NDTV said in a tweet. The U.K. added India to its travel ban list April 20, and earlier this month New Zealand temporarily suspended arrivals of its citizens and residents from India due to a spike in the number returning infected with COVID. Hong Kong banned flights from India, Pakistan and the Philippines for 14 days starting April 20, while Macau has extended the quarantine requirement for travelers from those three countries to 28 days.

--With assistance from Vrishti Beniwal, Saritha Rai, Supriya Batra and Kartik Goyal.