Health Secretary Sophia Chan said on Friday that the government will delay shipments of AstraZeneca's Covid-19 vaccine this year, amid mounting concerns over possible links between the shot and very rare cases of blood clots.

The government has ordered 7.5 million doses from the British-Swedish company and they were scheduled to arrive in the second half of 2021.

But Chan said the territory already has a sufficient supply of vaccines, after the delivery of 15 million doses of Germany's BioNTech and China's Sinovac.

"Even if we have signed a pre-purchase agreement with AstraZeneca, we believe that AstraZeneca vaccines will not need to be supplied to Hong Kong this year, so as not to cause a waste when the vaccine is still in short supply globally," Chan said.

The government was considering buying a new type of vaccine that may offer better protection, she added.

More than 700,000 Covid-19 vaccine doses have been administered to the city's 7.5 million population so far, a figure Chief Executive Carrie Lam said was unsatisfactory.

The sluggish take-up comes amid dwindling confidence in the Sinovac vaccine and fears of adverse reactions, while BioNTech vaccines were temporarily halted due to packaging defects. (Reuters)