BEIJING, April 19 (Reuters) - Chinese researchers are
testing the mixing of COVID-19 vaccine doses developed by
CanSino Biologics and a unit of Chongqing
Zhifei Biological Products, according to clinical
trial registration data.
Earlier this month, the director of the Chinese Center for
Disease Control and Prevention said the country was "formally
considering" giving people COVID-19 vaccine doses developed with
different technologies as a way of further boosting efficacy.
A trial expected to involve 120 participants will test the
safety and ability to trigger immune response of a dose of
CanSinoBIO's Ad5-nCoV treatment, followed by a dose of ZF2001
from Anhui Zhifei Longcom Biopharmaceutical at a 28-day or
56-day interval, according to clinical trial record site
ClinicalTrials.gov, which is maintained by a department under
the National Institute of Health of the United States.
The trial is sponsored by disease control authorities in the
eastern province of Jiangsu, where it is taking place, according
to the record.
CanSinoBIO and Chongqing Zhifei Biological Products were not
immediately available for comment.
Both vaccines are already being used in China's mass
CanSinoBIO said interim data from overseas Phase III
clinical trials showed its Ad5-nCoV vaccine was 68.83% effective
at preventing symptomatic COVID-19 disease two weeks after one
injection, while efficacy four weeks after one shot fell to
Chinese researchers are also running trials on a two-dose
Ad5-nCoV regimen, as well as an inhaled version of the vaccine.
The inhaled vaccine could achieve the same effect as one
injection with a much smaller dosage, local media The Paper
reported on Monday, citing an interview with CanSinoBIO chief
executive Yu Xuefeng.
No efficacy data has been made available from Phase III
trials for Zhifei Longcom's ZF2001 vaccine, which requires three
doses when used on its own.
(Reporting by Roxanne Liu and Ryan Woo; Editing by Kenneth
Maxwell, Kirsten Donovan)