India will lock down its capital New Delhi for a week from Monday night to try and control a raging coronavirus outbreak, as the hard-hit United States passed a hopeful milestone of giving at least one Covid-19 vaccine dose to half its adults.
There was good news from Australia and New Zealand as well as the two neighbours opened a travel bubble that would allow people to travel without a mandatory quarantine.
And in Europe, Greece said it would welcome vaccinated travellers from some countries as it sought to restart its badly-bruised tourism sector, while Portugal and Slovenia peeled back virus restrictions as infections eased off.
But India was still facing skyrocketing infections, with hospitals running out of beds and the government forced to reimpose economically painful restrictions again.
The capital New Delhi braced for a fresh lockdown as officials scrambled to get surging cases under control.
"Delhi's health system is at a tipping point. The Covid-19 situation is pretty critical," Delhi Chief Minister Arvind Kejriwal said.
"If we don't impose a lockdown now, we will be looking at a bigger disaster."
The Delhi lockdown came after the vast nation of 1.3 billion people reported a record high of 273,810 infections on Monday -- the fifth consecutive day of more than 200,000 cases.
India has the world's second-highest caseload with more than 15 million known infections.
The government said Monday it would make Covid vaccines available to all adults in the country from May 1, in a bid to beat back infections.
The soaring cases forced UK Prime Minister Boris Johnson to cancel a planned visit to the country this month, and Britain said Monday it would add India to its travel "red list", banning all arrivals from India except for UK or Irish nationals.
- US in 'precarious position' -
The coronavirus has killed more than three million people, devastating the world economy and upending daily life since first emerging in China in late 2019.
The United States remains the hardest-hit nation, with more deaths and known infections than anywhere else, but it passed a major vaccine milestone on Sunday with roughly 130 Americans -- half its adult population -- receiving at least one dose.
The country is a world leader in vaccinations, and all its over-18s will be eligible for a shot from Monday.
But its top pandemic adviser Anthony Fauci warned Sunday that the United States remains in a "precarious position".
"We're having a seven-day average of over 60,000 new infections per day. That's a place you don't want to be," he said.
"We also have to make sure that people don't throw caution to the wind and declare victory prematurely. That's not the time to do that."
Neighbouring Canada illustrated the threat of a fresh coronavirus wave, as authorities scrambled to funnel additional health staff and equipment into virus-hit Ontario to battle a surge in infections.
Ontario is Canada's most populous province, and record cases are threatening to overwhelm its healthcare system.
- 'Cry, hug, kiss' -
Across the Atlantic, there were glimmers of hope in Europe, as Portugal said it was reopening shopping malls, high schools and universities and that restaurants and cafes were allowed to offer outdoor dining.
"We are impatient to receive our customers again," said a happy Constanca Firmino, manager of a cosmetics shop in Lisbon.
Slovenia too eased restrictions after cases dropped, while Greece said some travellers from the EU, Britain, the United States, Israel, Serbia and the United Arab Emirates would not have to quarantine if they were fully vaccinated or had a negative Covid test.
Switzerland was also set to start the week with a step towards normality, with outdoor seating permitted at restaurants and bars and cinemas, sports facilities, and in-person classes at universities reopening.
And in Australia and New Zealand, there was joy and celebration as a long-awaited quarantine-free travel bubble opened across the Tasman Sea.
Family members tearfully reunited at airports in Sydney and Wellington, while others readied for their first outbound flights in more than a year.
"(I'll) yell, scream, cry, hug, kiss, (feel) happy -- all of these emotions at once," Denise O'Donoghue, 63, told AFP as she prepared to board her plane in Sydney.
"What normal is going to be from now on I don't know, but I'm just really, really excited today."