Australia's second-largest city Melbourne imposed an overnight curfew on Sunday to halt the spread of coronavirus cases, as South Africa's infection count topped more than half a million.
Six months after the World Health Organization declared a global emergency, the virus has killed more than 685,000 people and infected more than 17.8 million since it first emerged in China late last year.
Fresh clusters have been reported in countries — such as Australia — that had previously brought their outbreaks under control, forcing governments to reimpose lockdown measures to curb the spread despite worries over more economic fallout.
Australia's Victoria state imposed fresh, sweeping restrictions on Sunday, including a curfew in Melbourne for the next six weeks, a ban on weddings, and schools and universities going back online in the coming days.
"Anything short of this will see it drag on for months and months and months," said Victoria leader Daniel Andrews.
Despite a lockdown, Melbourne has continued to report hundreds of new cases daily even as other states in Australia have reported zero or a small number of cases.
Many other parts of the world are struggling with much bigger outbreaks.
Health authorities in South Africa who had been expecting a surge in cases after the gradual loosening of a strict lockdown reported that infections had exceeded the half-million mark.
The nation is by far the hardest-hit in Africa, accounting for more than half of diagnosed infections, although President Cyril Ramaphosa said the fatality rate is lower than the global average.
Latin America and the Caribbean passed a grim milestone on Sunday as fatalities in the region climbed over 200,000, with Brazil and Mexico accounting for nearly three-quarters of those deaths, according to an AFP tally compiled from official sources.
Iran — battling the Middle East's deadliest outbreak — on Sunday also reported its highest single-day infection count in nearly a month, warning that most of its provinces have been hit by a resurgence of the disease.
With infections and deaths soaring, the UN health agency, the World Health Organization (WHO), has said that the coronavirus pandemic is likely to be protracted and warned of possible "response fatigue".
"WHO continues to assess the global risk level of COVID-19 to be very high," the agency said, adding that the effects of the pandemic "will be felt for decades to come".
Mexico overtook Britain to become the third hardest-hit country in virus deaths — after Brazil and the United States — with more than 46,600 fatal cases.
The US, the worst-hit country in the world, has now tallied more than 4.6 million cases and 154,319 deaths.
The pandemic has spurred a race for a vaccine with several Chinese companies at the forefront, while Russia has set a target date of September to roll out its own prophylactic.
However, US infectious disease expert Anthony Fauci said it was unlikely his country would use any vaccine developed in either nation.
As part of its "Operation Warp Speed", the US government will pay pharmaceutical giants Sanofi and GSK up to $2.1 billion for the development of a COVID-19 vaccine, the companies said.
Even as the race for a vaccine heats up, the pandemic and the lockdowns to stop its spread have hammered the global economy.
France, Spain, Portugal and Italy all reported huge contractions in their economies for the April-June quarter, while Europe as a whole saw gross domestic product fall by 12.1 percent.
While many of the continent's outbreaks were largely brought under control, Switzerland's case numbers have crept up again in recent weeks, while Norway recorded its first virus death in two weeks.
Despite the resurgence in cases, Europe has seen demonstrations against coronavirus curbs.
Thousands protested in Berlin over the weekend urging "a day of freedom" from the restrictions, with some demonstrators dubbing the pandemic "the biggest conspiracy theory" — without offering any credible evidence.
The protests, in which many demonstrators failed to wear masks or respect social distancing rules, triggered calls for tougher penalties against those who violate safeguards against the spread of coronavirus.
At least 45 police were injured and more than 130 people were arrested.
The pandemic has also continued to cause mayhem in the travel, sports, cultural and tourism sectors, with more airlines announcing mass job cuts and major festivals and cultural events scaling back.
Latin America's biggest airline, the Brazilian-Chilean group LATAM, said it would lay off least 2,700 crew, and British Airways pilots overwhelmingly voted to accept a deal cutting wages by 20 percent, with 270 jobs lost.
Austria's month-long Salzburg festival celebrates its 100th anniversary, but now with a reduced programme and strict safety measures, including masks for spectators until they are seated and its 80,000 tickets — down from the usual 230,000 — personalised to enable contact-tracing.