http://sedac.ciesin.org/china/policy/acca21/218-1.html
China is one of only three countries in the world (along with the United States and India) now working on development of a contraceptive vaccine, a new generation method of birth control. It is expected that one dose of such a vaccine would last 1 to 1.5 years, thus proving simpler, more economical, and more effective than other alternatives, yet still reversible. Although most of the work to date has been on developing a vaccine for women, progress has also been made, and will continue on the more difficult task of isolating antigens to be used in a vaccine for men. China hopes to continue its work and eventually be able to provide these vaccines to other developing countries.