China aims to vaccinate 40 per cent of its population against Covid-19 by the end of July, a senior health adviser told Reuters, requiring a significant increase in inoculations even as it ramps up exports of vaccines.

Zhong Nanshan, a coronavirus expert who helped shape China's Covid-19 response, said the current ratio of vaccine doses administered per 100 people in China is 3.56, much lower than those in Israel, United Arab Emirates and the United States.

The 40pc by the end of July would include people who have received either one dose or two doses, Zhong said.