The Centre for Health Protection is investigating whether the human swine flu vaccine contributed to a 58-year-old man falling ill with Guillain-Barre Syndrome.

The man received the inoculation on December 24 and had weakness in his lower legs for a week before he was hospitalised on January 2. He is in a serious, but not life-threatening, condition.

Centre Controller Dr Thomas Tsang said the centre's expert group has not yet found a clear association between the vaccine and the disease - a rare neurological disorder causing paralysis and even respiratory difficulties.

Dr Tsang said there have been 40 to 60 cases of Guillain-Barre Syndrome annually in Hong Kong, showing the disease existed before the human swine flu vaccination programme.

He said the Government's human swine flu vaccination programme will continue unless there is a surge in the number of Guillain-Barre Syndrome cases. He recommended people in high-risk groups get inoculated against the virus before the winter flu peak.

Group member Prof Yuen Kwok-yung from the University of Hong Kong's Department of Microbiology said more tests are being conducted to find whether other sources caused the patient's Guillain-Barre Syndrome symptoms. He recommended people with allergies to eggs not have vaccinations.

Secretary for Food & Health Dr York Chow said the Government will check with the manufacturer whether there have been other serious effects caused by the same batch of vaccine.