Millions more Hong Kong residents are now eligible to receive COVID vaccines, the government announced after reporting about 30 new cases including two at the U.S. consulate Monday.

"We have considered the supply of vaccines and will expand the scope of priority groups," said civil service secretary Patrick Nip. People older than 30, foreign domestic helpers and students over 16 studying overseas are now eligible.

China's Sinovac Biotech Inc. vaccine has been available in Hong Kong since mid-February and last week the Pfizer Inc.-BioNTech SE jab made its debut in the city. But officials said Monday the lack of public enthusiasm for the inoculation program should be combated by expanded eligibility requirements.

"The more people who have been inoculated, the better," Hong Kong's secretary for food and health Sophia Chan said.

The city is on the precipice of a fourth wave. A 40-year-old man and 41-year-old woman working at the U.S. consulate in Central district tested positive for the virus Monday and had last been in the office March 12.

City authorities also reported another 13 new infections linked to the Ursus Fitness center cluster, bringing the total number of cases to 122 with another 860 close contacts sent to government quarantine for two weeks.

Police locked down 11 residential buildings in the Central and Western neighborhoods Monday to carry out mandatory testing.

The U.S. consulate immediately shut for deep cleaning and contact tracing and authorities took the opportunity to remind people to sign up for the vaccine.

"Hong Kong is one of the few places on earth where you can choose your vaccine type (and there is) sufficient supply," Nip said.

At least 70% of the population must be vaccinated for herd immunity to take effect, according to broad medical consensus. This is still a long way off for Hong Kong. To date, almost 200,000 of 7.5 million residents have had their first jab.