BEIJING, June 7 (Xinhua) -- China will make its COVID-19 vaccine a global public good when it is ready for application after successful research and clinical trials, a senior Chinese official said Sunday.

Wang Zhigang, minister of science and technology, said at a press conference in Beijing that international cooperation should be strengthened in vaccine development, clinical trials and application.

Vaccine development should focus on ensuring safety, effectiveness, and accessibility, Wang said.

To date, four inactivated vaccines and one adenovirus vaccine have been approved for clinical trials, said a white paper titled "Fighting COVID-19: China in Action," which was released by the State Council Information Office on Sunday.

While scientists in China and abroad have kept up with mutual developments, China leads the world in the development of certain types of vaccines, the white paper said.

A great deal of international cooperation had been carried out so far on vaccine development, Wang said.

Highlighting the significant role that vaccines had played in human history, Wang said both Chinese scientists and those in other countries are trying to make contributions to building a global community of health for all.

He however noted that the development of vaccines is a rigorous and complex procedure, which faces many uncertainties and may take a long period of time.