Scientists in China are working on an AIDS vaccine to protect against three variants of HIV that are becoming more prevalent in Hong Kong, Taiwan and southern and western China, Reuters reports (, 1/21).

Two closely related HIV strains have spread through intravenous drug use, according to the article; another strain has spread mainly through heterosexual sex, predominantly in the Yunnan and southern Guangxi provinces.

"If you want to make a vaccine, it is better to have a local strain as a target to work on," said Chen Zhiwei, director of the new AIDS Institute in Hong Kong.

According to Chen, collaborating scientists in the U.S. and China have designed a vaccine based on the two HIV variants spread by intravenous drug use. They hope to test it on animals by the end of this year.

An estimated 700,000 people are living with HIV/AIDS in China.