Only 30 percent of elderly aged 70 or above is vaccinated, which is not satisfactory, Nip said on Sunday.

On Saturday, government advisor Thomas Tsang Ho-fai said on Saturday that the low vaccination rate in elderly centers is a ticking bomb.

In response to the comment, Nip admitted the vaccination rate of elderly home residents in Hong Kong – which is around 10 percent – is much lower than overseas.

“This situation is quite worrying,” he said.

The low rate will also weaken the mainland's confidence in Hong Kong's ability to suppress outbreaks, and is an obstacle to reopening borders, he said.