Vaccine shares rose while mainland poultry companies declined on the stock market yesterday as the H7N9 bird flu scare in eastern China triggered speculation that Beijing could order a cull to prevent an epidemic.

Four people in Jiangsu province were reportedly fighting for their lives after it was confirmed they were infected with the virus.

According to social networking site Sina Weibo, one of the patients is a 45-year-old Jiangsu woman, who worked as a poultry butcher at a local market.