Australia on Wednesday began human trials for a swine flu vaccine, lending new urgency to global efforts to curb the pandemic after the death toll worldwide leapt past 700. As the trials started, Thailand's death toll reached 44 to overtake Australia's as the biggest in the Asia-Pacific region. In Latin America, Chile's toll jumped from 40 to 68. The human trials at Australia's Royal Adelaide Hospital involve some 240 adults and 400 children. 'As soon as I have confirmation that the vaccine is safe and effective, I will ensure it can be rolled out to the community,' Health Minister Nicola Roxon said. Australia has pre-ordered 21 million shots of vaccine from CSL Biotherapies -- enough to cover its whole population -- after being badly hit by A(H1N1) with more than 14,000 cases and 38 deaths linked to the disease. Scientists fear swine flu could mutate to a more deadly form in a reprise of the Spanish and Asian influenza pandemics of 1918 and 1958. CSL spokeswoman Rachel David said many people had volunteered for the vaccine trial because they wanted to avoid catching the disease. 'We're talking about kids aged between six months and nine years and it involves two injections and two blood tests, so four needles to monitor the results,' she told public broadcaster ABC. 'I think that is a big commitment for families, but in spite of that we've had a number of people come forward because they're interested in not getting the flu.' On Tuesday, a 19-year-old Aboriginal woman with swine flu lost her unborn child, prompting warnings by Australian authorities to expectant mothers to avoid crowds and protect themselves with flu shots. The woman, who remains in serious condition, comes from Palm Island in Australia's northeast, where doctors fear some 10 percent of the 3,500 population may have been infected, according to The Australian. The newspaper also said the mother-of-two, Alma Palmer, had been sent home from hospital with paracetamol a day before collapsing and being airlifted to the mainland. Hospitals have complained they are under growing pressure. A Sydney intensive care specialist said hospitals were 'tearing their hair out' to find enough staff to cope with the influx of patients. A union in Queensland state has also warned that up to 20 percent of nurses could be put on sick leave with swine flu during the ongoing southern hemisphere winter, double the normal figure. The World Health Organization on Tuesday said the global death toll had shot up from 439 to more than 700, a 40 percent leap from early July. In Thailand, the latest death toll of 44 was almost double the figure released last week. 'I am not surprised at the high number because there was a backlog (of testing) from last week,' said Thai Prime Minister Abhisit Vejjajiva. In Tonga, health officials said doctors had performed emergency surgery to deliver the baby of a woman who died days later to become the Pacific country's first swine flu fatality. Latin America was still being hit hard, with Chile's health ministry announcing the country's death toll had jumped to 68. Argentina has announced 168 confirmed fatalities to become the world's second worst-affected country, behind only the United States, where 263 people have died of swine flu. Concerns about the virus forced the cancellation of a 227-year-old Catholic pilgrimage in Costa Rica. And with upwards of two million people expected in Saudi Arabia over the next five months on pilgrimages to Mecca and Medina, Egypt advised vulnerable Muslims such as the elderly and pregnant women to stay home. In Britain, the Financial Times reported that some Church of England worshippers were being advised to hug rather than shake hands. 