WUHAN: World Health Organization experts emerged from quarantine in China on Thursday to begin a long-awaited inquiry into the origins of the coronavirus pandemic, with the United States and Beijing sparring over the nature of the probe.
The investigators are in Wuhan, the Chinese city where the virus emerged more than a year ago before going on to infect more than 100 million and kill more than two million worldwide.
China's handling of the initial outbreak is under renewed scrutiny as governments around the world push on with vaccine campaigns, squabble over supplies of the jabs, and navigate the tricky politics of shutdowns.
After months of lobbying -- and two weeks of quarantine -- the WHO experts were finally able to set off for work on Thursday.
"So proud to graduate from our 14 days... no-one went stir crazy & we've been v productive," tweeted team member Peter Daszak after the investigators left their quarantine hotel wearing masks, peering out of their bus window at the gathered media.
- 'Misinformation' jibe -
However, it remained unclear when they would get to start their investigation and what they would be allowed to see.
China has sought to deflect blame for the massive global human and economic toll by suggesting -- without proof -- that the virus emerged somewhere else. It has also been enraged by calls led by the United States and Australia for an independent probe.
"It's imperative that we get to the bottom of the early days of the pandemic in China, and we've been supportive of an international investigation that we feel should be robust and clear," White House spokeswoman Jen Psaki said Wednesday.
She also expressed concern about "misinformation" from "some sources in China".
Beijing shot back Thursday, warning against "political interference" in the WHO mission.
Relatives of those who died in Wuhan have accused Chinese authorities of deleting their social media group and putting pressure on them to keep quiet, apparently to avoid any embarrassment during the WHO probe.
- Dose delays outrage EU -
The virus has continued to hammer countries across the world despite the onset of mass vaccination programmes that have already seen more than 82 million doses injected, according to an AFP count compiled from national figures.
In Europe, a bitter row has broke out between the EU and drug company AstraZeneca over reductions in the supply of its jabs.
The EU has called on AstraZeneca to make up for delays by supplying doses from its factories in the UK -- but Britain too insists the firm honour its delivery promises, and AstraZeneca has said there is simply not enough to go around.
Adding to the AstraZeneca controversy, Germany's vaccine commission on Thursday recommended the jab should not be used on people aged over 65, saying there was "insufficient data" confirming it works on older recipients.
Pfizer, which developed its own vaccine with German firm BioNTech, has also faced EU criticism for delays in deliveries but has now revised its production target for this year up from 1.3 billion doses to two billion.
Pfizer and BioNTech also said Thursday that their jab was effective against more contagious strains that have emerged in Britain and South Africa -- days after another vaccine-maker, Moderna, said the same.
- 'Solid ground' -
Vaccines are considered critical to eventually defeating Covid-19, which has continued to re-emerge even in nations where it was previously brought under control.
Vietnam has recorded its first cases for months, while New Zealand has launched an inquiry over two people who tested positive after leaving a quarantine hotel.
With herd immunity still a distant dream, the most powerful tools for policymakers remain social-distancing measures, enforced mask wearing, curfews, lockdowns and travel bans.
Germany is considering banning all travel from countries affected by the new variants, and the WHO warned Europeans it was too early to lift restrictions despite the rate of new infections slowing.
The persistence of the virus has led to constant questioning of whether this summer's Tokyo Olympics will go ahead, but sports officials moved to quash the doubts on Thursday.
International Olympic Committee chief Thomas Bach insisted he was committed to holding the Games, though he admitted for the first time that fans may be barred.
Tokyo 2020 President Yoshiro Mori hailed the commitment, saying: "We are still on solid ground... Bach gave us his strong stance, and we are thankful for that."