China's Covid-19 vaccines using the inactivated virus can be upgraded to cope with new variants in about two months, according to a Chinese medical expert.
Shao Yiming, a scientist with the Chinese Centre for Disease Control and Prevention agency, was speaking to the Global Times, in a report published on Tuesday.
There are concerns that vaccines developed over the past year may be less effective again new variants of Covid-19 discovered recently in the UK and South Africa.
Biotech company Moderna said on Monday it would test a new booster shot aimed at the South African variant, after concluding the antibody response could be diminished.
Vaccines from Sinovac Biotech and China National Pharmaceutical Group (Sinopharm) are being used in China and overseas. The Sinopharm vaccine is approved for use in the UAE.
These vaccines contain the inactivated virus that cannot replicate in human cells.
The neutralising ability of antibodies induced by Chinese vaccines, which were developed in accordance with the variant spreading in Wuhan city in late 2019, appeared weaker against recently discovered variants in the UK and South Africa, the Global Times quoted Mr Shao as saying.
He cited studies by Chinese vaccine companies and labs.
The redesign of inactivated Covid-19 vaccines could take longer than for vaccines based on mRNA technology, which does not require cultivating and inactivating the virus, according to Mr Shao, who participates in technical reviews of China's Covid-19 vaccines.
The mRNA technology is used in vaccines developed by Pfizer-BioNTech and Moderna.
The Global Times is published by the People's Daily, the official newspaper of China's ruling Communist Party.