Authorities are investigating whether a 73-year-old who developed limb numbness after a swine flu jab on December 31 has Guillain-Barre syndrome, the Centre for Health Protection said. She was admitted to Kwong Wah Hospital on March 11 and was in a critical condition yesterday. Meanwhile, an 18-month-old boy who contracted swine flu was in a critical condition in Tuen Mun Hospital. He has a history of neurometabolic disease and epilepsy.