Seasonal flu vaccinations across Australia for children under five have been suspended after 23 children in Western Australia were admitted to hospital with convulsions following their injections.
One child, aged 1, remains in a coma in a Perth hospital.
Commonwealth chief health officer Professor Jim Bishop yesterday announced the suspension while authorities urgently review data from around the country.
WA chief health officer Dr Tarun Weeramanthri told journalists that 44 children under 10 had been admitted to Perth's Princess Margaret Hospital for Children over the past month suffering febrile convulsions - fits or seizures due to high fever seen mainly in children.
He said 23 of those children had received flu injections in the previous 12 hours.
Authorities were still investigating whether the remaining 21 cases were connected to the vaccinations.
Another 40 children had been admitted to hospitals in WA over the same period suffering febrile convulsions, but it was not known whether they had received the flu vaccine.
Professor Bishop said a preliminary review by the Therapeutic Goods Administration had narrowed the problems to WA, but an expert group would work to identify any gaps.
Victorian Health Department spokesman Bram Alexander said he was unaware of any febrile convulsions connected to the vaccine in Victoria.
He said the Royal Children's Hospital had advised that it had not seen any increase in the number of children admitted with febrile convulsions since the start of the year.
All states have been asked to report any adverse reactions to the seasonal flu vaccine, including batch numbers and type of vaccine. Professor Bishop wants details by the end of next week.
Asked about the coming flu season, he said: ''We have a little bit of time but not much.''
He expected a mild season dominated by swine flu. He said the swine flu vaccine Panvax, already given to 8 million Australians, was ''safe and effective'' and available free.
Authorities will investigate whether the adverse reactions in WA are due to the vaccine itself. Professor Bishop said the maker of the vaccine, CSL, had been contacted to determine which batches had been sent to WA.
He said the seasonal flu vaccine had been well received by older children and adults, and people should be reassured that a potential problem had been detected.
A spokeswoman for the federal Health Department, Kay McNiece, said authorities were still working to find out how many seasonal flu vaccinations had been given this year.
Federal government figures show there were 655 suspected adverse reactions to the flu vaccine reported between 2004 and 2008. About 8 million doses are administered each year.
With WEST AUSTRALIAN, SMH