Beijing: China has given conditional approval for a single dose COVID-19 vaccine, touted to be a rival to Johnson & Johnson’s one-jab shot cleared by the US drug regulator on Sunday.China's first Ad5-nCoV COVID-19 vaccine was rolled out on Friday, the state-run Global Times reported on Sunday.Phase-I clinical trials of the vaccine started on March 16, last year, making it the world's first COVID-19 candidate vaccine that entered clinical trials, it said.It is the only single-dose COVID-19 vaccine that has been given conditional approval to be rolled out in China, the report quoted last Friday’s story by the state broadcaster China Central Television (CCTV).People can get desirable protective effect after 14 days of inoculation.The.