China reported its 10th death and five more cases of H7N9 bird flu on Thursday, as state media said scientists were developing a vaccine that would be ready within seven months.
The eastern commercial hub of Shanghai, the area worst-hit by the virus, reported three new infections including a 74-year-old man who died on Thursday afternoon.
Health authorities in nearby Jiangsu province said they had confirmed two more infections in a 31-year-old chef, who was in critical condition, and a 56-year-old teacher.
The new cases brought the nationwide total to 38 confirmed infections, including 10 deaths, in Shanghai, Jiangsu and the neighboring provinces of Anhui and Zhejiang.
Scientists would start work on the vaccine this week, the official Xinhua news agency reported.
Chinese authorities and the World Health Organization have played down fears of an epidemic, saying there is no evidence of human-to-human transmission.
Shanghai culled chickens and other fowl at markets in the city last week after the virus was found in pigeons nearby.