The government announced on Wednesday that more residents would be eligible for the BioNTech bivalent shots, which contain components of the original coronavirus strain and Omicron one. The bivalent vaccine was made available last Thursday to uninfected adults as a fourth dose and recovered individuals as a third dose. The Chinese-made Sinovac shots are also being offered, along with the original doses made by Germany’s BioNTech.

Official statistics show 47,742 people were given a fourth shot in the week up to Wednesday, compared with 9,232 seven days earlier. Among them, 38,654 received the bivalent vaccine. The number of residents who have received a fourth dose now stands at more than 632,000.

Authorities have ordered 1.9 million shots of the BioNTech bivalent vaccine so far, with the first batch of 770,000 arriving in the city on November 25.

Starting from Friday, adults can book appointments for the new vaccine as their third dose, or second shot if they were previously infected, after experts from the city’s scientific committees earlier recommended the jab be made available to the wider population.

Beginning December 16, residents aged 18 or older who had taken four doses can book a fifth dose of either the bivalent vaccine or the two original vaccines. The same is being offered for previously infected adults with three doses and who received the last shot or recovered more than six months ago seeking a fourth dose.

Respiratory specialist Dr Leung Chi-chiu appealed to elderly people and other high-risk groups including those living in care homes, as well as those who were immunocompromised or suffering from chronic diseases, to receive a fourth shot given a rebound in Covid-19 cases.

“A fourth jab is mainly to prevent hospitalisation, severe illness and death,” he said.