That comes with many schools on their way to achieving a 90-percent vaccination rate for students - well above the required line.

His hope came after authorities announced that youngsters from 12 to 17 can get a Sinovac jab from next Thursday.

Currently, 70 percent of secondary students have had BioNTech shots, Lau said. "Students had no choice and could only receive the BioNTech vaccine earlier, and I assume the 30 percent of unvaccinated students were waiting for Sinovac jabs."

"I hope secondary school students can get vaccinated as soon as possible after they are allowed to take the Sinovac shots and push the vaccination rate to 90 percent or nearly 100 percent by Christmas."

If students achieve such a rate, Lau said, all 506 secondary schools in Hong Kong can resume full-day classes and students can join in extracurricular activities.

He added that many schools need only 10 to 20 more students to be inoculated to reach the key 70-percent vaccination rate to resume full-day classes.

Lau also said primary school students and younger kids should be allowed to receive Sinovac jabs in January or February if there is a good response from secondary students to the program.

Authorities could also arrange for children to be vaccinated with their family, he said.

According to Education Bureau statistics, 63 secondary schools had resumed full-day classes for all grades as of November 4.

The data also showed 299 secondary schools - 59 percent of the total - were seeking a resumption of full-day classes, with 82 applying in respect of an entire school and 217 for certain grades.

Meanwhile, Pfizer Inc and the BioNTech company have announced their Covid-19 vaccine is safe and effective for youngsters from 12 to 15 as shown in updated findings from a trial running for four months after second doses were administered. The US Food and Drug Administration has also approved the vaccine for emergency use in 12 to 15-year-olds.

The SAR administration lowered the age requirement for the BioNTech vaccine to 12 in June.

Macau lowered the age limit for taking Sinopharm vaccines from 12 to three from yesterday, allowing parents to make bookings for their kids.

Macau authorities also offered a slight change in restrictions for arrivals from Hong Kong yesterday, saying they could enter the SAR with a negative Covid-19 testing result from within 72 hours rather than from one conducted within 24 hours.

But Hong Kong travelers will still have to undergo a 14-day quarantine upon arrival in Macau.

Under the Return2hk or Come2hk scheme, however, travelers from Macau can be exempted from quarantine after arriving in Hong Kong.