The number of coronavirus cases recorded worldwide passed the 18-million mark on Monday, with the World Health Organization warning that the effects of the pandemic "will be felt for decades to come".
The virus that causes Covid-19 has killed more than 687,000 people since it first emerged in China late last year, according to an AFP tally compiled from official sources.
Fresh clusters have been reported in countries that had previously brought their outbreaks under control, forcing governments to reimpose lockdown measures despite worries over further 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 wedding gatherings, and an order that schools and universities go back online in the coming days.
"Anything short of this will see it drag on for months and months and months," Victoria premier Daniel Andrews said of the outbreak.
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.
Many other parts of the world are struggling with much bigger outbreaks.
Health authorities in South Africa, where a surge in cases had been expected after the gradual loosening of a strict lockdown, reported that infections 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 another milestone on Sunday as fatalities in the region climbed to more than 200,000, with Brazil and Mexico accounting for nearly three-quarters.
Iran — battling the Middle East's deadliest outbreak — 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 still surging six months after it declared a global health emergency, the World Health Organization has warned of possible "response fatigue".
"The WHO continues to assess the global risk level of COVID-19 to be very high," the UN health agency said, adding that the effects of the pandemic "will be felt for decades to come."
Europe case numbers creep up again
The deadly 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 the United States 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 two companies have said.
The US has now tallied more than 4.6 million cases and 154,793 deaths, while neighbouring Mexico has overtaken Britain to become the third-hardest-hit country in virus deaths — after Brazil and the US — with more than 46,600 fatal cases.
Read More – Source