FRANKFURT/BERLIN, Nov 30 (Reuters) - The chief executive of drugmaker Moderna set off fresh alarm bells in financial markets on Tuesday with a warning that existing COVID-19 vaccines would be less effective against the new Omicron variant than they have been against Delta.

Major European stock markets fell around 1.5% in early trade, Tokyo's Nikkei index closed down 1.6%, crude oil futures shed more than 3%, and the Australian dollar hit a one-year low as Stephane Bancel's comments spurred fears that vaccine resistance may prolong the pandemic.

"There is no world, I think, where (the effectiveness) is the same level . . . we had with Delta," Bancel told the Financial Times.

"I think it's going to be a material drop. I just don't know how much because we need to wait for the data. But all the scientists I've talked to . . . are like 'this is not going to be good'," Bancel said.

Balancing that, however, European Medicines Agency (EMA) executive director Emer Cooke told the European Parliament that even if the new variant becomes more widespread, existing vaccines will continue to provide protection.

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Andrea Ammon, who chairs the European Centre for Disease prevention and Control (ECDC), said 42 cases of the variant had been confirmed in 10 EU countries. There were another six "probable" cases.

She said the cases were mild or without symptoms, although in younger age groups.

The University of Oxford said there was no evidence that current vaccines would not prevent severe disease from Omicron, but that it was ready to rapidly develop an updated version of its shot, developed with AstraZeneca, if necessary.

Moderna did not reply to a Reuters request for comment, or say when it expects to have data on the effectiveness of its vaccine on Omicron, which the World Health Organization (WHO) says carries a very high risk of infection surges.

News of its emergence wiped roughly $2 trillion off global stocks on Friday, after it was identified in southern Africa and announced on Nov. 25.

And yet Dutch authorities said the variant had been detected in the Netherlands as early as Nov. 19, before two flights arrived from South Africa that were known to have carried the virus.

The WHO and scientists have also said it could take weeks to understand whether Omicron is likely to cause severe illness or escape protection against immunity induced by vaccines.

Cooke said lab tests for "cross neutralization" would take about two weeks. If there were a need to change COVID-19 vaccines, new ones could be approved within three or four months, she added.

"Vaccination will likely still keep you out of the hospital," said John Wherry, director of the Penn Institute for Immunology in Philadelphia.

Moderna and fellow drugmakers BioNTech and Johnson & Johnson are working on vaccines that specifically target Omicron in case existing shots are not effective against it. Moderna has also been testing a higher dose of its existing booster.

Uncertainty about the new variant has triggered global alarm, with border closures casting a shadow over a nascent economic recovery from the two-year-old pandemic, just as parts of Europe see a fourth wave of infections as winter sets in.

Japan, the world's third largest economy, confirmed its first case on Tuesday, in a traveler from Namibia. Australia found that a person with Omicron had visited a busy shopping center in Sydney while probably infectious.

A Singapore Airlines plane arriving from Singapore lands at the international terminal at Sydney Airport, as countries react to the new coronavirus Omicron variant amid the coronavirus disease (COVID-19) pandemic, in Sydney, Australia, on November 30, 2021. REUTERS/Loren Elliott
A Singapore Airlines plane arriving from Singapore lands at the international terminal at Sydney Airport, as countries react to the new coronavirus Omicron variant amid the coronavirus disease (COVID-19) pandemic, in Sydney, Australia, on November 30, 2021. REUTERS/Loren Elliott

BORDER CONTROLS

Countries around the world have tightened border controls in an attempt to prevent a recurrence of last year's strict lockdowns and steep economic downturns.

Many have focused, to South Africa's fury, on banning flights to and from southern Africa.

Britain and the United States have both pushed their booster programs. England made face masks compulsory once again in shops and on public transport. International arrivals will have to self-isolate until they get a negative result in a PCR test for viral DNA.

Greece said it would make vaccination compulsory for the over-60s, the group seen as most vulnerable to the new coronavirus.

Australia has delayed the reopening of its international borders by two weeks, less than 36 hours before foreign students and skilled migrants were to be allowed back.

In Germany, a hotspot, the average seven-day infection rate fell slightly for the first time in three weeks as officials considered imposing tougher measures.

The global curbs on travelers from southern Africa have highlighted the inequality of vaccine distribution, which may have given the virus more opportunities to mutate.

The passenger liner Europa was docking in Cape Town on Tuesday in what was meant to be the official start of the first cruise ship season in South Africa's top tourist hub since the pandemic.

After Omicron was discovered while they were at sea, many passengers were expected to fly straight home.

(Reporting by Reuters bureaus worldwide; writing by Himani Sarkar and Kevin Liffey; editing by Shri Navratnam, Andrew Cawthorne and Nick Macfie.)