China bio firm dispels fears of serious blood clots from its COVID-19 vaccine

Screenshot of the official website of China's CanSino Biologics Inc (CanSinoBIO)

China's CanSino Biologics Inc (CanSinoBIO) has said that no serious blood clot cases were reported in the recipients of its COVID-19 vaccine Ad5-nCoV.

"No blood clot related serious adverse events have been reported in around one million vaccinations of Ad5-nCoV," CanSinoBIO said in a statement on Wednesday.

The statement came after U.S. federal health agencies on Tuesday called for a pause of the use of Johnson & Johnson's COVID-19 vaccine, which applies a similar technology to Ad5-nCoV, following some blood clots reports.

Although both vaccines developed by CanSinoBIO and Johnson & Johnson's contained another virus called adenovirus, CanSinoBIO's vaccine uses a different adenovirus from that for Johnson & Johnson's.

In mid-January, Russian pharma Petrovax said that 92.5 percent of Russian volunteers in trials of the Ad5-nCoV vaccine had shown high levels of antibodies, according to Russia's Interfax news agency.

So far, the Ad5-nCoV vaccine has been approved for emergency use in China, Hungary, Chile, Mexico and Pakistan.