China's CanSino Biologics Inc said on Wednesday that no serious blood clot cases had been reported so far in people who were injected with its COVID-19 vaccine Ad5-nCoV.
The announcement follows U.S. federal health agencies' recommendation on Tuesday that use of Johnson & Johnson's COVID-19 vaccine, which uses a similar technology to CanSinoBIO's product, should be paused for at least a few days, after six women younger than 50 developed rare blood clots after receiving the shot.
"No blood clot related serious adverse events have been reported in around one million vaccinations of Ad5-nCoV," CanSinoBIO said in a filing.
CanSinoBIO's shares fell as much as 13.7% and 18.4% in Shanghai and Hong Kong, respectively, in morning trading.
Vaccines from Johnson & Johnson and CanSinoBIO contain another virus called adenoviruses, which have been modified to essentially render them harmless.
The adenoviruses are employed as a vector to ferry instructions for human cells to make parts of the new coronavirus, triggering the immune system to produce antibodies against it.
CanSinoBIO's COVID-19 vaccine, which has been approved in China and secured deal in Mexico, uses a different adenovirus than that for Johnson & Johnson's.
(Reporting by Shashwat Awasthi in Bengaluru and Roxanne Liu and Ryan Woo in Beijing; Editing by Shounak Dasgupta) ((Shashwat.Awasthi@thomsonreuters.com))