China develops 71 vaccines, ranking first around world 1 China is researching and developing 71 vaccines against COVID-19 and they are effective against the Delta strain, China's top epidemiologist Zhong Nanshan revealed over the weekend, making China the country with the largest number of vaccines undergoing research, experts said. Experts reached by the Global Times said if approved, those vaccines will satisfy urgent domestic and overseas demand as health authorities will gradually ramp up efforts to approve more vaccines. They will also provide a chance for the country to explore new technologies to develop vaccines against future infectious diseases that may be more severe than COVID-19.