The Centre for Health Protection is investigating a suspected case of Guillain-Barre Syndrome involving a 26-year-old woman.

She received flu vaccination from a private doctor on October 23, but was admitted to Prince of Wales Hospital on November 14 with weak limbs. She is now in stable condition.

The Working Group on Influenza Vaccination under the centre's Scientific Committee on Vaccine Preventable Diseases will study the case.

Guillain-Barre Syndrome mainly presents itself through varying degrees of weakness or tingling sensations in the legs, and may occasionally affect the arms and upper body. Most people recover while some may have more permanent effects.

The World Health Organisation says the association between the disease and influenza vaccines is inconclusive. Noting flu vaccine side effects are usually mild and well tolerated, the centre said the benefits outweigh its risk.