The world's top health official said on Wednesday that a vaccine to combat the surging swine flu pandemic would not be readily available for months as the number of deaths from the virus spiralled.
The comments by World Health Organization chief Margaret Chan came as Australia and Japan reported a surge in cases of the A(H1N1) virus, and Argentina dramatically upped its death toll from 94 to 137 in just three days.
"There's no vaccine. One should be available soon, in August. But having a vaccine available is not the same as having a vaccine that has proven safe," Chan told Britain's Guardian newspaper.
"Clinical trial data will not be available for another two to three months," she added, contradicting health officials in Britain and elsewhere who said the first stocks would start arriving in August.
WHO director of vaccine research Marie-Paul Kieny, calling the pandemic "unstoppable", had said on Monday that a swine flu vaccine should be available as early as September.
Germany said it envisaged having to order some 25 million doses of vaccine to immunise nearly a third of its population.
Australia, the Asia-Pacific region's worst-hit country, has already placed an advance order for 21 million doses, enough to immunise its entire population.
Australia and Argentina are now in the southern hemispheric winter, and officials fear a major rise in infections when the northern hemisphere enters the colder months and regular influenza becomes rampant.
Italy may have to deal with between three and four million cases of swine flu by March 2010, deputy health minister Ferruccio Fazio said.
He said that by the end of this year some 8.6 million Italians would have been vaccinated against the A(H1N1) virus, with priority given to the most vulnerable and to emergency workers.
Argentina's new death toll made it the worst-hit nation in terms of fatalities after the United States, which has 211 deaths and 37,000 confirmed infections according to the latest tally.
Mexico, the third most afflicted country with 124 deaths and 12,521 infections, said late Tuesday that swine flu cases were picking up in the southeast, especially in Chiapas state near Guatemala.
Health ministers from six South American countries were to meet Wednesday to seek a coordinated response. Argentina was to host the meeting of ministers from Bolivia, Brazil, Chile, Paraguay and Uruguay.
Not including the latest figures from Argentina, the WHO's global death toll from swine flu stands at 429 with more than 94,500 infections tallied worldwide.
Australia said its total of swine flu cases had reached 10,387, more than 10 percent of the WHO's global total. The country suspects swine flu was the culprit in the deaths of some 20 people.
Health Minister Nicola Roxon said the real number could be much higher, and warned that health authorities were now worried about a growing number of serious cases in young people.
"We do see that there are some people who are young and otherwise healthy who have the rapidly deteriorating disease ... it's obviously concerning," she said.
Some 15,000 doctors in Peru called for a nationwide protest on Wednesday to demand better prevention against swine flu, which has claimed at least five lives and infected around 2,000 people in the South American nation.
"We demand addressing adequately the needs of hospitals in order to prevent further mistakes in the treatment of swine flu and to avoid more deaths," Leoncio Diaz, president of the Peruvian Medical Federation, told AFP.
Fears over swine flu also prompted French football club AS Nancy to scrap a pre-season trip to Britain, which is Europe's worst hit country.