A health worker prepares to administers the Sinovac vaccine against the Covid-19 coronavirus at Zainoel Abidin Hospital in Banda Aceh on January 25, 2021. / AFP / CHAIDEER MAHYUDDIN
A health worker prepares to administer the Sinovac vaccine against the Covid-19 coronavirus at Zainoel Abidin Hospital in Indonesia. AFP

Chinese Covid vaccine booster 'could upgrade shot against variants'


The National