Ebony Shearer began life weighing little more than a feather duster, but today she is pioneering the fight against a bona fide health heavyweight.The Appin six-year-old is the first NSW child to take part in world-leading swine flu vaccine trials on children.She will receive the injection at Westmead Children's Hospital this morning - and not a minute too soon, her mother Natalie Shearer says."I was worried that if she did get the swine flu she wouldn't deal with it," she said. "She would probably end up in hospital."Ebony was born at 24 weeks gestation, weighing just 610g and with arms so tiny they could fit through her dad's wedding ring. Her survival, after 4 1/2 months in hospital and a year on a breathing machine, was considered a miracle.However, her rocky beginning left her lungs forever compromised and as a result she is prone to chest infections and colds, and has only just recovered from a bout of whooping cough she picked up in January.Mrs Shearer pulled her daughter out of school two weeks ago.She wanted to protect her from the swine flu pandemic, and was so keen to see her vaccinated she was preparing to fly her to the Royal Adelaide Hospital, where adult vaccine trials began on July 22.''She knows she'll be able to play with the other kids if she gets the needle,'' Mrs Shearer said.Westmead Children's Hospital will trial the drug on 80 to 100 children. Another 300 to 320 will receive injections in Brisbane, Melbourne, Adelaide and Perth.The trials are intended to determine the appropriate vaccine dosage for children, with two different dose strengths and amounts being tested.Mrs Shearer's other children, Bridget, 2, and William, nine months, will also take part in the trial this week.She said she would be ''watching very closely'' for adverse signs.However, Westmead's professor of child health, Robert Booy, said side effects were likely to be the same as those produced by the seasonal flu vaccine - a sore arm with redness and swelling, a temperature and muscle aches within the first two days.''It's produced in exactly the same way as the vaccine we produce for children every year, so we're not envisaging additional risks,'' Professor Booy said.For Ebony, the best part of the experience will be its conclusion.She anticipates a lollipop for her trouble, and is looking forward to returning to school ''because my friends miss me''. As of Friday, 77 Australians who had tested positive to the virus had died, including 30 in NSW.Young people are among those most at risk of a severe reaction because they are unlikely to have immunity to the virus.Parents interested in registering their child in the trial at Westmead can phone 9845 1430 or 9845 1408. A vaccine is expected to be made available to the wider population late this year.