Experts are investigating cases of illness in two patients who received the human swine flu vaccination.

The Centre for Health Protection received reports today a 34-year-old man received the vaccination on December 21. He had a headache on February 20, followed by double vision the following day. He was hospitalised on February 21 and is stable.

An 80-year-old man with a history of hypertension, heart disease, renal impairment and asthma was inoculated December 29. He suffered limb paralysis and lost his voice on February 5 and was hospitalised. He is being investigated for transverse myelitis and other neurological conditions. He is in critical condition with stable vital signs.

The expert group which studies such cases will meet February 25 to discuss also an intrauterine death involving a 28-year-old woman reported on February 12, and suspected Guillain Barre Syndrome in a 75-year-old woman following her swine flu vaccination on February 17.

The centre reiterated a baseline number of such neurological conditions and intrauterine deaths occur in Hong Kong every year. Some of the events are expected to occur coincidentally following swine flu vaccination.